- A 24-year-old college soccer player collapses suddenly during a match and has no pulse. He was previously asymptomatic, but an autopsy of a relative who died young showed asymmetric thickening of the interventricular septum. Which condition is the most likely cause of his collapse?
- Innocent flow murmur
- Acute viral pericarditis
- Mitral annular calcification
- Hypertrophic cardiomyopathy
Correct answer: Hypertrophic cardiomyopathy
Hypertrophic cardiomyopathy is the answer. It is the most common cause of sudden cardiac death in young athletes, arising from a genetic disorder of the sarcomere that produces asymmetric septal hypertrophy and predisposes to malignant ventricular arrhythmias during exertion. The family history of asymmetric septal thickening strongly supports this inherited disorder.
- A patient with hypertrophic cardiomyopathy and recurrent syncope is found to have a high risk of sudden cardiac death despite optimal medical therapy. Which intervention most directly reduces his risk of dying from a malignant arrhythmia?
- Placement of an implantable cardioverter-defibrillator
- Initiating an angiotensin receptor blocker
- Starting a long-acting nitrate
- Beginning a thiazide diuretic
Correct answer: Placement of an implantable cardioverter-defibrillator
Placement of an implantable cardioverter-defibrillator is the answer. In hypertrophic cardiomyopathy patients at high risk for sudden death, the defibrillator detects and terminates life-threatening ventricular arrhythmias. Medications such as nitrates and diuretics reduce preload and can worsen the dynamic obstruction rather than prevent arrhythmic death.
- A 68-year-old with atrial fibrillation is started on warfarin for stroke prevention. Which laboratory value is used to monitor and adjust his dose?
- International normalized ratio
- Anti-factor Xa level routinely
- Platelet count
- Activated partial thromboplastin time
Correct answer: International normalized ratio
International normalized ratio is the answer. Warfarin inhibits vitamin K-dependent clotting factors, and its effect is monitored with the international normalized ratio, which is targeted to a therapeutic range for atrial fibrillation. The activated partial thromboplastin time is used for unfractionated heparin, not warfarin.
- A 72-year-old man with nonvalvular atrial fibrillation cannot reliably attend frequent laboratory monitoring. Which class of anticoagulant offers stroke prevention without the need for routine coagulation testing?
- Direct oral anticoagulants
- Vitamin K antagonists
- Antiplatelet aspirin monotherapy
- Unfractionated heparin infusions
Correct answer: Direct oral anticoagulants
Direct oral anticoagulants are the answer. Agents such as apixaban and rivaroxaban provide effective stroke prevention in nonvalvular atrial fibrillation with fixed dosing and no requirement for routine coagulation monitoring. Vitamin K antagonists require frequent international normalized ratio checks, and aspirin alone is inferior for stroke prevention.
- A medication used to treat torsades de pointes works by stabilizing the cardiac membrane and is given intravenously even when the serum level appears normal. Which electrolyte abnormality, in addition to a long QT, is most commonly corrected to help prevent recurrence?
- Hypernatremia
- Hypercalcemia
- Hyperphosphatemia
- Hypomagnesemia
Correct answer: Hypomagnesemia
Hypomagnesemia is the answer. Low magnesium predisposes to QT prolongation and torsades de pointes, so repleting magnesium both treats and helps prevent recurrence of the rhythm. Correcting coexisting hypokalemia is also important, but the listed electrolyte that classically requires repletion is magnesium.
- A 2-year-old with tetralogy of Fallot suddenly becomes deeply cyanotic and irritable while crying, then instinctively squats. Which physiologic effect of squatting relieves these hypercyanotic spells?
- It increases systemic vascular resistance and reduces right-to-left shunting
- It decreases systemic venous return abruptly
- It lowers pulmonary vascular resistance
- It opens the ductus arteriosus
Correct answer: It increases systemic vascular resistance and reduces right-to-left shunting
Increasing systemic vascular resistance and reducing right-to-left shunting is the answer. Squatting kinks the femoral arteries and raises afterload, which forces more blood across the pulmonary outflow tract instead of shunting right to left, improving oxygenation during a tet spell. This is why children with tetralogy of Fallot instinctively squat.
- A neonate with coarctation of the aorta develops shock and poor lower-body perfusion when the ductus arteriosus begins to close. Which medication is most appropriate to maintain ductal patency until surgical correction?
- Propranolol
- Prostaglandin E1 (alprostadil)
- Furosemide
- Indomethacin
Correct answer: Prostaglandin E1 (alprostadil)
Prostaglandin E1 (alprostadil) is the answer. In ductal-dependent lesions such as critical coarctation, an infusion of prostaglandin E1 keeps the ductus arteriosus open to maintain perfusion to the lower body until repair can be performed. Indomethacin has the opposite effect and is used to close a patent ductus.
- A 76-year-old with known severe aortic stenosis is considered too high-risk for open surgery. Which less invasive procedure can replace the stenotic valve in such a patient?
- Pericardiocentesis
- Mitral valve commissurotomy
- Coronary artery bypass grafting
- Transcatheter aortic valve replacement
Correct answer: Transcatheter aortic valve replacement
Transcatheter aortic valve replacement is the answer. This catheter-based approach delivers a prosthetic valve without open heart surgery and is used for patients with severe symptomatic aortic stenosis who are at high or prohibitive surgical risk. It directly relieves the fixed outflow obstruction.
- A 58-year-old man with chronic mitral regurgitation develops progressive left ventricular dilation, and echocardiography now shows a declining ejection fraction. Which mechanism explains why his left ventricle initially compensated before failing?
- The mitral valve became stenotic over time
- The left ventricle ejected part of its stroke volume backward into the low-pressure left atrium
- The pericardium thickened and restricted filling
- The aorta progressively narrowed
Correct answer: The left ventricle ejected part of its stroke volume backward into the low-pressure left atrium
Ejecting part of the stroke volume backward into the low-pressure left atrium is the answer. In chronic mitral regurgitation the ventricle unloads into the low-resistance atrium, which masks dysfunction for years until progressive volume overload causes dilation and eventual systolic failure. This is why ejection fraction can appear preserved until late.
- A patient being evaluated for suspected infective endocarditis needs imaging to look for valvular vegetations. Which test is the most sensitive noninvasive study for detecting small vegetations?
- Chest radiography
- Transesophageal echocardiography
- Coronary angiography
- Transthoracic echocardiography
Correct answer: Transesophageal echocardiography
Transesophageal echocardiography is the answer. Because the probe sits directly behind the heart, it provides superior resolution of the valves and is more sensitive than transthoracic echocardiography for detecting small vegetations and complications such as abscess. This makes it valuable when suspicion remains high despite a negative transthoracic study.
- A patient develops constrictive physiology years after an episode of acute pericarditis, with Kussmaul sign and a pericardial knock. Which hemodynamic abnormality best characterizes constrictive pericarditis?
- Obstruction of the left ventricular outflow tract
- Acute valvular regurgitation
- A large left-to-right intracardiac shunt
- Impaired ventricular filling due to a rigid, scarred pericardium
Correct answer: Impaired ventricular filling due to a rigid, scarred pericardium
Impaired ventricular filling due to a rigid, scarred pericardium is the answer. Constrictive pericarditis results from a thickened, noncompliant pericardium that limits diastolic filling, producing elevated venous pressures, Kussmaul sign, and a pericardial knock. The constraint on filling distinguishes it from outflow obstruction or valvular disease.
- A 70-year-old with a known 4.2 cm asymptomatic abdominal aortic aneurysm is asymptomatic on routine follow-up. According to standard surveillance practice, which is the most appropriate management?
- No further imaging is ever needed
- Begin lifelong full-dose anticoagulation
- Periodic ultrasound surveillance for growth
- Immediate open surgical repair
Correct answer: Periodic ultrasound surveillance for growth
Periodic ultrasound surveillance for growth is the answer. Abdominal aortic aneurysms below the 5.5 cm repair threshold are monitored with serial imaging because the rupture risk remains low until they enlarge. Smoking cessation and blood pressure control are also recommended, while elective repair is reserved for larger or rapidly expanding aneurysms.
- A 62-year-old with an acute ST elevation myocardial infarction develops a new harsh holosystolic murmur and acute pulmonary edema three days later. Which mechanical complication is most consistent with this finding?
- Ventricular septal rupture
- Pericardial effusion without tamponade
- Atrial myxoma
- Sinus bradycardia
Correct answer: Ventricular septal rupture
Ventricular septal rupture is the answer. A new holosystolic murmur with abrupt hemodynamic deterioration several days after myocardial infarction suggests rupture of the interventricular septum, creating a left-to-right shunt. This mechanical complication is a surgical emergency and is distinct from the gradual course of uncomplicated infarction.
- A 60-year-old with peripheral artery disease has rest pain in the foot at night and a nonhealing ulcer on the toe. This presentation of advanced limb ischemia is best described by which term?
- Superficial thrombophlebitis
- Raynaud phenomenon
- Critical limb ischemia
- Intermittent claudication
Correct answer: Critical limb ischemia
Critical limb ischemia is the answer. Rest pain, nonhealing ulcers, and tissue loss reflect severe arterial insufficiency that threatens limb viability, a stage beyond simple claudication. This advanced presentation often requires revascularization to prevent amputation.
- A 45-year-old develops sudden severe tearing chest pain radiating to the back. Which underlying condition is the single most important risk factor for the aortic dissection that is suspected?
- Poorly controlled hypertension
- Atrial fibrillation
- Mild mitral stenosis
- Hyperlipidemia
Correct answer: Poorly controlled hypertension
Poorly controlled hypertension is the answer. Chronic hypertension is the most important and common risk factor for aortic dissection because sustained high pressure weakens and stresses the aortic wall. Connective tissue disorders also contribute, but hypertension is the predominant risk in most patients.
- A patient with a Stanford type B aortic dissection involving only the descending aorta is hemodynamically stable without complications. Which is the preferred initial management?
- Emergent open surgical repair
- Immediate thrombolytic therapy
- Pericardiocentesis
- Aggressive blood pressure and heart rate control with medications
Correct answer: Aggressive blood pressure and heart rate control with medications
Aggressive blood pressure and heart rate control with medications is the answer. Uncomplicated type B dissections that spare the ascending aorta are managed initially with medical therapy using agents such as beta-blockers to lower shear stress on the aortic wall. Surgery is reserved for ascending (type A) dissections or complicated type B cases.
- A patient with new-onset heart failure has a markedly elevated B-type natriuretic peptide level. What does this biomarker primarily reflect?
- Acute coronary plaque rupture
- Increased ventricular wall stress from volume or pressure overload
- Pericardial inflammation
- Skeletal muscle injury
Correct answer: Increased ventricular wall stress from volume or pressure overload
Increased ventricular wall stress from volume or pressure overload is the answer. B-type natriuretic peptide is released by stretched ventricular myocardium and rises in heart failure, helping distinguish cardiac from pulmonary causes of dyspnea. It reflects wall stress rather than coronary or pericardial pathology.
- A patient with heart failure with reduced ejection fraction remains symptomatic on an ACE inhibitor and beta-blocker. Adding which class of medication provides additional mortality benefit by blocking aldosterone?
- Dihydropyridine calcium channel blockers
- Class I antiarrhythmics
- Alpha-blockers
- Mineralocorticoid receptor antagonists
Correct answer: Mineralocorticoid receptor antagonists
Mineralocorticoid receptor antagonists are the answer. Agents such as spironolactone or eplerenone block aldosterone, reduce adverse remodeling, and improve survival in heart failure with reduced ejection fraction when added to standard therapy. The other listed classes do not provide this mortality benefit.
- A patient presenting with acute decompensated heart failure has pulmonary congestion and elevated jugular venous pressure. Which class of medication is first-line to relieve the volume overload?
- Loop diuretics
- Antiarrhythmics
- Beta-blockers
- Calcium channel blockers
Correct answer: Loop diuretics
Loop diuretics are the answer. In acute decompensated heart failure with volume overload, loop diuretics such as furosemide rapidly reduce preload and relieve pulmonary and systemic congestion. Beta-blockers are generally not initiated or up-titrated during acute decompensation.
- A patient with cardiac tamponade is hemodynamically unstable. Which procedure provides the most immediate relief by removing fluid compressing the heart?
- Cardioversion
- Pericardiocentesis
- Thoracentesis
- Coronary stenting
Correct answer: Pericardiocentesis
Pericardiocentesis is the answer. Aspirating the pericardial fluid relieves the external compression on the heart, restoring filling and cardiac output in tamponade. Thoracentesis drains the pleural space and does not address the pericardial fluid causing the obstruction.
- A 55-year-old man has a clinic blood pressure of 158/96 mmHg confirmed on repeat visits with no evidence of secondary causes. Which lifestyle modification typically produces the greatest reduction in blood pressure for an overweight patient?
- Weight loss
- Reducing dietary potassium
- Avoiding all aerobic exercise
- Increasing dietary sodium
Correct answer: Weight loss
Weight loss is the answer. In overweight or obese hypertensive patients, weight reduction is among the most effective lifestyle interventions for lowering blood pressure, often yielding substantial decreases. Reducing sodium and increasing physical activity also help, but the choice that best fits this overweight patient is weight loss.
- A 50-year-old African American patient with stage 2 hypertension and no other compelling indications needs pharmacologic therapy. Which is an appropriate first-line agent class for initial blood pressure control in this population?
- Digoxin
- Short-acting nitrate
- Calcium channel blocker or thiazide diuretic
- Loop diuretic monotherapy
Correct answer: Calcium channel blocker or thiazide diuretic
A calcium channel blocker or thiazide diuretic is the answer. For Black adults without heart failure or chronic kidney disease, guidelines favor initiating therapy with a calcium channel blocker or thiazide-type diuretic for effective blood pressure lowering. Loop diuretics and digoxin are not first-line antihypertensives.
- A newborn with a large patent ductus arteriosus develops signs of pulmonary overcirculation. Which medication can be used to promote closure of the ductus in a preterm infant?
- Adenosine
- Indomethacin
- Prostaglandin E1
- Dopamine
Correct answer: Indomethacin
Indomethacin is the answer. As a prostaglandin synthesis inhibitor, indomethacin promotes closure of a patent ductus arteriosus in preterm infants. Prostaglandin E1 has the opposite effect and is used to keep the ductus open in ductal-dependent lesions.
- An adult with a longstanding large atrial septal defect develops reversal of the shunt to right-to-left with cyanosis as pulmonary pressures rise. This complication of an uncorrected left-to-right shunt is known as which syndrome?
- Brugada syndrome
- Dressler syndrome
- Marfan syndrome
- Eisenmenger syndrome
Correct answer: Eisenmenger syndrome
Eisenmenger syndrome is the answer. Chronic left-to-right shunting raises pulmonary vascular resistance until the pressures reverse the shunt to right-to-left, producing cyanosis. Once Eisenmenger physiology develops, the defect is generally no longer surgically correctable.
- A 64-year-old presents with crescendo chest pain occurring at rest and with minimal exertion over the past two days, but troponin levels are normal and there is no ST elevation. Which diagnosis best fits this presentation?
- Unstable angina
- Stable chronic angina
- ST elevation myocardial infarction
- Acute pericarditis
Correct answer: Unstable angina
Unstable angina is the answer. New or worsening anginal chest pain at rest or with minimal exertion, without a rise in troponin, defines unstable angina, an acute coronary syndrome caused by a partially occlusive thrombus. The normal troponin distinguishes it from non-ST elevation myocardial infarction.
- A patient diagnosed with an acute coronary syndrome is given a medication that irreversibly inhibits platelet cyclooxygenase to reduce further thrombus formation. Which drug is being described?
- Warfarin
- Metoprolol
- Aspirin
- Atorvastatin
Correct answer: Aspirin
Aspirin is the answer. It irreversibly inhibits platelet cyclooxygenase, reducing thromboxane-mediated platelet aggregation, and is given promptly in acute coronary syndromes to limit thrombus propagation. Warfarin acts on clotting factors rather than platelets.
- A patient develops fever, pleuritic chest pain, and a pericardial effusion several weeks after a myocardial infarction. Which post-infarction complication does this delayed immune-mediated pericarditis represent?
- Papillary muscle rupture
- Ventricular aneurysm
- Dressler syndrome
- Reinfarction
Correct answer: Dressler syndrome
Dressler syndrome is the answer. This is a delayed, immune-mediated pericarditis occurring weeks after myocardial infarction, presenting with fever, pleuritic chest pain, and a pericardial effusion. It is treated with anti-inflammatory agents and is distinct from the acute mechanical complications of infarction.
- A patient with chest pain has an electrocardiogram showing ST elevation in leads V1 and V2 with reciprocal changes, and there is concern for involvement of the wall supplied by the left anterior descending artery. Which heart sound or finding would suggest the infarct has impaired ventricular relaxation, producing a stiff ventricle?
- A fixed split S2
- An opening snap
- A fourth heart sound (S4)
- A continuous machine-like murmur
Correct answer: A fourth heart sound (S4)
A fourth heart sound (S4) is the answer. An S4 results from atrial contraction against a stiff, noncompliant ventricle, which can occur acutely with ischemia that impairs ventricular relaxation. A fixed split S2 and an opening snap point to unrelated structural conditions.
- A 30-year-old has frequent palpitations, and an electrocardiogram captures isolated wide QRS complexes occurring earlier than expected, each followed by a compensatory pause, with no preceding P wave. Which is the most likely description of these beats?
- Junctional escape beats
- Premature atrial contractions
- Premature ventricular contractions
- Sinus pauses
Correct answer: Premature ventricular contractions
Premature ventricular contractions are the answer. Early, wide QRS complexes without a preceding P wave and followed by a compensatory pause are characteristic of premature ventricular contractions, which originate in the ventricle. Premature atrial contractions produce narrow complexes preceded by abnormal P waves.
- An elderly patient on the monitor shows a heart rate of 40 beats per minute with a normal narrow QRS and a P wave preceding each QRS at a consistent PR interval. He is asymptomatic. Which rhythm is present?
- Atrial fibrillation
- Complete heart block
- Sinus bradycardia
- Ventricular tachycardia
Correct answer: Sinus bradycardia
Sinus bradycardia is the answer. A slow rate below 60 with a P wave preceding every QRS and a consistent PR interval defines sinus bradycardia, which is often benign in healthy or athletic individuals. The preserved one-to-one atrioventricular relationship distinguishes it from heart block.
- A symptomatic patient with persistent high-grade Mobitz type II atrioventricular block and bradycardia is at risk of progression to complete heart block. Which definitive treatment is most appropriate?
- Long-term atropine therapy
- Beta-blocker initiation
- Adenosine administration
- Permanent pacemaker placement
Correct answer: Permanent pacemaker placement
Permanent pacemaker placement is the answer. Mobitz type II block frequently progresses to complete heart block and carries a risk of asystole, so a permanent pacemaker is the definitive treatment for symptomatic or high-grade disease. Beta-blockers would worsen the conduction delay.
- A patient with chest pain has an electrocardiogram demonstrating a QRS duration greater than 120 milliseconds with a broad R wave in lead I and V6 and a deep S in V1. Which conduction abnormality is most consistent with this pattern?
- Right bundle branch block
- Wolff-Parkinson-White pattern
- First-degree atrioventricular block
- Left bundle branch block
Correct answer: Left bundle branch block
Left bundle branch block is the answer. A wide QRS with broad, notched R waves in the lateral leads I and V6 and a deep S wave in V1 is characteristic of left bundle branch block, which reflects delayed left ventricular activation. This pattern can also obscure the diagnosis of acute myocardial infarction.
- A patient develops profound bradycardia and hypotension after an inferior wall myocardial infarction, reflecting ischemia of the artery that often supplies the sinoatrial and atrioventricular nodes. Which artery is most often responsible for supplying these nodes?
- Left main coronary artery
- Left circumflex artery
- Right coronary artery
- Left anterior descending artery
Correct answer: Right coronary artery
The right coronary artery is the answer. In most people the right coronary artery supplies the sinoatrial and atrioventricular nodes, so inferior infarction from right coronary occlusion commonly produces bradyarrhythmias and conduction block. This explains the bradycardia accompanying inferior infarcts.
- A patient is found to have an irregularly irregular pulse, and the electrocardiogram confirms atrial fibrillation. Which is the most common identifiable chronic condition predisposing to atrial fibrillation in adults?
- Hypertension
- Migraine
- Hypothyroidism
- Iron deficiency
Correct answer: Hypertension
Hypertension is the answer. Chronic hypertension is the most common condition associated with atrial fibrillation because it causes left atrial enlargement and structural remodeling that promote the arrhythmia. Treating the underlying hypertension is part of long-term management.
- A 19-year-old asymptomatic patient is incidentally noted to have a soft, short systolic murmur at the left sternal border that disappears when she stands and has no other abnormal findings. Which is the most likely explanation?
- A large ventricular septal defect
- Severe aortic stenosis
- Mitral stenosis
- An innocent (functional) flow murmur
Correct answer: An innocent (functional) flow murmur
An innocent (functional) flow murmur is the answer. A soft, short, position-dependent systolic murmur in an asymptomatic young person with otherwise normal findings is typical of a benign flow murmur. The lack of associated symptoms or abnormal signs argues against significant structural valvular disease.
- A 26-year-old develops Raynaud-like episodes plus a new diastolic murmur, and echocardiography reveals a pedunculated mass attached to the interatrial septum that causes a tumor plop and intermittent mitral inflow obstruction. Which cardiac diagnosis is most likely?
- Infective endocarditis
- Mitral valve prolapse
- Atrial myxoma
- Aortic dissection
Correct answer: Atrial myxoma
Atrial myxoma is the answer. A pedunculated mass on the interatrial septum that intermittently obstructs the mitral valve produces a tumor plop and positional symptoms, the classic features of the most common primary cardiac tumor. Surgical removal is the definitive treatment.
- A patient with newly diagnosed hypertension is found on screening to have hypokalemia and metabolic alkalosis without diuretic use, raising concern for a secondary endocrine cause acting through excess mineralocorticoid effect on the cardiovascular system. Which secondary cause of hypertension is most consistent with these findings?
- Coarctation of the aorta
- Renal artery stenosis from fibromuscular dysplasia
- White-coat hypertension
- Primary hyperaldosteronism
Correct answer: Primary hyperaldosteronism
Primary hyperaldosteronism is the answer. Excess aldosterone causes sodium retention with hypertension along with potassium wasting and metabolic alkalosis, the classic biochemical clues. This endocrine-mediated mineralocorticoid excess is a recognized secondary cause of hypertension.
- A patient presents with severe substernal pressure and the electrocardiogram shows ST elevation in leads V5, V6, I, and aVL. Which region of the heart is infarcting?
- Lateral wall
- Anterior wall
- Inferior wall
- Posterior wall
Correct answer: Lateral wall
The lateral wall is the answer. ST elevation in leads I, aVL, V5, and V6 localizes to the lateral wall, typically supplied by the left circumflex artery or a diagonal branch. This pattern is distinct from the inferior leads II, III, and aVF.
- A patient with an inferior ST elevation myocardial infarction develops hypotension, clear lung fields, and elevated jugular venous pressure, and right-sided leads show ST elevation. Which intervention is most appropriate for the suspected right ventricular infarction?
- Aggressive nitroglycerin therapy
- Cautious intravenous fluid administration
- High-dose loop diuretics
- Beta-blocker bolus
Correct answer: Cautious intravenous fluid administration
Cautious intravenous fluid administration is the answer. Right ventricular infarction causes hypotension with clear lungs and elevated venous pressure because the failing right ventricle is preload-dependent, so fluids support output. Nitrates and diuretics reduce preload and can precipitate severe hypotension in this setting.
- A patient several days after a large anterior myocardial infarction is found to have persistent ST elevation and a bulging, dyskinetic region of the left ventricle on echocardiography. Which late complication does this most likely represent?
- Papillary muscle rupture
- Acute pericarditis
- Left ventricular aneurysm
- New mitral stenosis
Correct answer: Left ventricular aneurysm
Left ventricular aneurysm is the answer. Persistent ST elevation weeks after infarction with a dyskinetic, bulging ventricular wall suggests a true left ventricular aneurysm formed from scarred myocardium. It can predispose to mural thrombus, arrhythmias, and heart failure.
- A 55-year-old with stable angina is prescribed sublingual nitroglycerin for acute episodes. Through which primary mechanism does nitroglycerin relieve anginal chest pain?
- Blocking calcium channels in the atrioventricular node
- Direct coronary thrombolysis
- Venodilation that reduces preload and myocardial oxygen demand
- Increasing heart rate and contractility
Correct answer: Venodilation that reduces preload and myocardial oxygen demand
Venodilation that reduces preload and myocardial oxygen demand is the answer. Nitroglycerin predominantly dilates veins, lowering preload and ventricular wall stress so the heart needs less oxygen, and it also dilates coronary arteries. This reduction in demand relieves the ischemic chest pain of angina.
- A 70-year-old man reports brief episodes of lightheadedness and one syncopal event. Holter monitoring shows alternating periods of bradycardia and supraventricular tachycardia. Which disorder of the sinus node does this tachy-brady pattern most suggest?
- Complete heart block
- Atrial flutter alone
- Wolff-Parkinson-White syndrome
- Sick sinus syndrome
Correct answer: Sick sinus syndrome
Sick sinus syndrome is the answer. The alternating bradycardia and tachycardia, or tachy-brady syndrome, reflects sinoatrial node dysfunction and often causes syncope or near-syncope. Symptomatic disease frequently requires a permanent pacemaker.
- A patient taking digoxin for rate control presents with nausea, visual disturbances described as yellow-green halos, and a new arrhythmia. Which finding most strongly suggests digoxin toxicity as the cause of these symptoms?
- Isolated hypertension
- The combination of gastrointestinal upset, yellow-green vision changes, and arrhythmia
- A widened pulse pressure
- A continuous machine-like murmur
Correct answer: The combination of gastrointestinal upset, yellow-green vision changes, and arrhythmia
The combination of gastrointestinal upset, yellow-green vision changes, and arrhythmia is the answer. This classic triad reflects digoxin toxicity, which can also be precipitated by hypokalemia and renal impairment. Recognizing the constellation prompts measurement of the digoxin level and appropriate management.
- A patient with severe symptomatic rheumatic mitral stenosis and favorable valve anatomy is being considered for intervention. Which procedure is often preferred to relieve the obstruction when the valve is suitable?
- Aortic valve replacement
- Percutaneous balloon mitral valvuloplasty
- Coronary artery bypass grafting
- Pericardiocentesis
Correct answer: Percutaneous balloon mitral valvuloplasty
Percutaneous balloon mitral valvuloplasty is the answer. In symptomatic mitral stenosis with suitable, noncalcified valve anatomy and no significant regurgitation, balloon valvuloplasty can open the fused commissures and relieve the obstruction. It is often preferred over surgery when the anatomy is favorable.
- A 35-year-old woman with mitral valve prolapse is generally asymptomatic. Which is the most common associated symptom or finding that may occur with this condition?
- Fixed split second heart sound
- Atypical chest pain or palpitations
- Continuous machine-like murmur
- Cyanosis at rest
Correct answer: Atypical chest pain or palpitations
Atypical chest pain or palpitations is the answer. Although many patients with mitral valve prolapse are asymptomatic, atypical chest pain and palpitations are the symptoms most often reported. Cyanosis and a fixed split S2 are features of unrelated congenital lesions.
- A 45-year-old with aortic regurgitation has a head bob with each heartbeat and visible pulsations of the nail beds. These peripheral signs of a hyperdynamic circulation result primarily from which hemodynamic feature?
- A wide pulse pressure from large stroke volume and diastolic runoff
- Reduced stroke volume
- A narrow pulse pressure from fixed outflow obstruction
- Pulsus paradoxus
Correct answer: A wide pulse pressure from large stroke volume and diastolic runoff
A wide pulse pressure from large stroke volume and diastolic runoff is the answer. In chronic aortic regurgitation the ventricle ejects a large stroke volume while blood runs back during diastole, widening the pulse pressure and producing signs such as head bobbing and nail-bed pulsations. These dynamic peripheral signs are hallmarks of significant aortic regurgitation.
- A patient with longstanding poorly controlled hypertension is found on echocardiography to have a thick-walled left ventricle. Which compensatory change does this represent, and why is it clinically important?
- Acute pericardial effusion
- A congenital septal defect
- Dilated cardiomyopathy from infection
- Concentric left ventricular hypertrophy, which raises the risk of diastolic dysfunction and arrhythmia
Correct answer: Concentric left ventricular hypertrophy, which raises the risk of diastolic dysfunction and arrhythmia
Concentric left ventricular hypertrophy is the answer. Chronic pressure overload from hypertension causes the ventricular wall to thicken, which increases the risk of diastolic dysfunction, arrhythmias, and ischemia. Recognizing it underscores the importance of blood pressure control.
- A patient with hypertension is started on an angiotensin-converting enzyme inhibitor and later develops a persistent dry cough. Which mechanism explains this common side effect?
- Calcium channel inhibition
- Direct beta-receptor blockade
- Accumulation of bradykinin
- Aldosterone excess
Correct answer: Accumulation of bradykinin
Accumulation of bradykinin is the answer. Angiotensin-converting enzyme inhibitors block the breakdown of bradykinin, and its buildup is responsible for the characteristic dry cough that can lead to switching to an angiotensin receptor blocker. This mechanism is specific to this drug class.
- A 50-year-old develops sudden severe substernal chest pain and is hypotensive, and an electrocardiogram shows ST elevation in leads II, III, and aVF along with bradycardia. Beyond aspirin and reperfusion, why should nitroglycerin be used cautiously in this presentation?
- It can cause severe hypotension if there is right ventricular involvement
- It dissolves the coronary stent
- It raises the heart rate dangerously
- It directly causes ventricular fibrillation
Correct answer: It can cause severe hypotension if there is right ventricular involvement
It can cause severe hypotension if there is right ventricular involvement is the answer. Inferior infarctions can involve the preload-dependent right ventricle, and nitroglycerin reduces preload, which may precipitate profound hypotension. This caution is important before giving nitrates in inferior ST elevation myocardial infarction.
- A patient with chronic stable angina has a coronary angiogram showing significant three-vessel disease including the proximal left anterior descending artery, and he has diabetes. Which revascularization strategy is often favored in this scenario?
- Coronary artery bypass grafting
- Medical therapy with no revascularization ever
- Pericardiocentesis
- Single-vessel stenting only
Correct answer: Coronary artery bypass grafting
Coronary artery bypass grafting is the answer. In patients with complex multivessel disease, particularly diabetics with proximal left anterior descending involvement, surgical bypass often provides better outcomes than percutaneous intervention. This makes bypass the favored revascularization approach in such cases.
- A patient develops sudden tearing chest pain and is found to have an ascending aortic aneurysm. Which inherited connective tissue disorder is most classically associated with aortic root dilation and dissection in young patients?
- Klinefelter syndrome
- Marfan syndrome
- Sturge-Weber syndrome
- Down syndrome
Correct answer: Marfan syndrome
Marfan syndrome is the answer. This connective tissue disorder weakens the aortic wall, predisposing tall, long-limbed patients to aortic root dilation, aneurysm, and dissection at a young age. Regular imaging surveillance of the aorta is recommended in affected individuals.
- A patient develops painful, red, tender cord-like swelling along a superficial leg vein without deep system involvement. Which condition is most likely?
- Cellulitis of the entire limb
- Superficial thrombophlebitis
- Deep vein thrombosis
- Arterial embolism
Correct answer: Superficial thrombophlebitis
Superficial thrombophlebitis is the answer. Inflammation and clot in a superficial vein produces a tender, palpable, cord-like erythematous streak along its course. It is usually managed conservatively, though extension toward the deep system warrants closer evaluation.
- A young woman reports that her fingers turn white, then blue, then red with cold exposure or stress, with normal pulses between episodes. Which vasospastic condition does this color sequence describe?
- Peripheral artery disease
- Raynaud phenomenon
- Buerger disease
- Acute arterial embolism
Correct answer: Raynaud phenomenon
Raynaud phenomenon is the answer. The classic triphasic color change of white to blue to red with cold or stress, with normal perfusion between attacks, reflects episodic digital arterial vasospasm. It contrasts with fixed obstructive arterial disease.
- A patient with longstanding diabetes has resting tachycardia and orthostatic hypotension attributed to autonomic dysfunction of the cardiovascular system. Which physical finding best supports orthostatic hypotension?
- A fixed split second heart sound
- Pulsus paradoxus
- A sustained drop in blood pressure when moving from lying to standing
- A widened pulse pressure at rest
Correct answer: A sustained drop in blood pressure when moving from lying to standing
A sustained drop in blood pressure when moving from lying to standing is the answer. Orthostatic hypotension is defined by a significant fall in blood pressure on standing, which in diabetics may reflect autonomic neuropathy impairing cardiovascular reflexes. Measuring positional blood pressures confirms the diagnosis.
- A patient with an acute coronary syndrome is started on a P2Y12 inhibitor in addition to aspirin to provide dual antiplatelet therapy. Which medication is an example of a P2Y12 receptor inhibitor?
- Warfarin
- Lisinopril
- Clopidogrel
- Furosemide
Correct answer: Clopidogrel
Clopidogrel is the answer. It inhibits the platelet P2Y12 receptor and is combined with aspirin for dual antiplatelet therapy after acute coronary syndromes and stent placement. Warfarin and the other agents do not act on this platelet pathway.
- A patient with heart failure with reduced ejection fraction is started on a newer combination agent containing sacubitril and valsartan. Sacubitril provides benefit by inhibiting which enzyme?
- Neprilysin
- HMG-CoA reductase
- Carbonic anhydrase
- Cyclooxygenase
Correct answer: Neprilysin
Neprilysin is the answer. Sacubitril inhibits neprilysin, which prevents breakdown of natriuretic peptides and promotes vasodilation and natriuresis, and combined with valsartan it improves outcomes in heart failure with reduced ejection fraction. This combination is a guideline-directed therapy for the condition.
- An asymptomatic 55-year-old man undergoes lipid screening showing markedly elevated low-density lipoprotein and tendon xanthomas, with a strong family history of early myocardial infarction. Which condition is most likely?
- Acute pericarditis
- Familial hypercholesterolemia
- Atrial septal defect
- Hypertensive emergency
Correct answer: Familial hypercholesterolemia
Familial hypercholesterolemia is the answer. Very high low-density lipoprotein levels, tendon xanthomas, and premature coronary disease in the family suggest this inherited disorder of cholesterol metabolism. Early aggressive lipid lowering reduces the substantial cardiovascular risk.
- A patient is in cardiac arrest with an organized rhythm on the monitor but no palpable pulse. Which term describes this clinical state, and what is the immediate priority?
- Sinus tachycardia, requiring observation
- Pulseless electrical activity, requiring chest compressions and a search for reversible causes
- Atrial flutter, requiring rate control
- Ventricular fibrillation, requiring immediate defibrillation only
Correct answer: Pulseless electrical activity, requiring chest compressions and a search for reversible causes
Pulseless electrical activity, requiring chest compressions and a search for reversible causes, is the answer. When the monitor shows organized electrical activity but there is no pulse, the priority is high-quality CPR while addressing reversible causes such as hypovolemia or tension pneumothorax. Defibrillation is not indicated for this nonshockable rhythm.
- A patient with severe hyperlipidemia is started on a statin and later reports diffuse muscle aches with a rise in creatine kinase. Which adverse effect of statins does this most likely represent?
- Statin-associated myopathy
- Aortic dissection
- Hyperkalemia
- Pericarditis
Correct answer: Statin-associated myopathy
Statin-associated myopathy is the answer. Statins can cause muscle aches and elevated creatine kinase, ranging from mild myalgias to rare rhabdomyolysis, prompting evaluation and possible dose adjustment. Recognizing this side effect guides safe lipid management.
- A 30-year-old develops fever, weight loss, and a new regurgitant murmur, and blood cultures are persistently positive. According to the diagnostic framework for endocarditis, persistently positive blood cultures with a typical organism represents which type of diagnostic criterion?
- An unrelated finding
- A minor criterion
- An exclusion criterion
- A major criterion
Correct answer: A major criterion
A major criterion is the answer. Within the Duke criteria, persistently positive blood cultures with typical endocarditis organisms count as a major criterion, as does echocardiographic evidence of endocardial involvement. Combining major and minor criteria establishes the diagnosis of infective endocarditis.
- A patient with prosthetic heart valves and high cardiac risk requires a dental procedure with gingival manipulation. Which intervention is recommended before the procedure to reduce the risk of infective endocarditis?
- Routine echocardiography
- Antibiotic prophylaxis before the procedure
- Long-term anticoagulation increase
- Beta-blocker administration
Correct answer: Antibiotic prophylaxis before the procedure
Antibiotic prophylaxis before the procedure is the answer. Patients with the highest-risk cardiac conditions, such as prosthetic valves, receive antibiotic prophylaxis prior to dental procedures involving gingival manipulation to prevent endocarditis. This targeted prophylaxis reflects current guideline recommendations.
- A patient on the monitor develops an irregularly irregular narrow-complex tachycardia, and on closer inspection there are at least three distinct P-wave morphologies at varying rates. This rhythm, often seen with severe lung disease, is best described as which arrhythmia?
- Sinus arrhythmia
- Atrial flutter with fixed block
- Multifocal atrial tachycardia
- Junctional rhythm
Correct answer: Multifocal atrial tachycardia
Multifocal atrial tachycardia is the answer. The presence of three or more distinct P-wave morphologies with varying rates produces an irregularly irregular rhythm classically associated with severe chronic lung disease. Treating the underlying pulmonary condition is central to management.
- A patient has a blood pressure that is consistently elevated only in the clinic but normal on repeated home and ambulatory measurements, with no end-organ damage. Which term best describes this pattern?
- White-coat hypertension
- Malignant hypertension
- Secondary hypertension
- Hypertensive emergency
Correct answer: White-coat hypertension
White-coat hypertension is the answer. Blood pressure that is elevated in the office but normal outside it, without target-organ damage, defines white-coat hypertension. Confirming it with ambulatory or home monitoring avoids unnecessary treatment.
- A patient presents with acute pulmonary edema, severe respiratory distress, and a blood pressure of 220/120 mmHg. In addition to controlled blood pressure reduction, which finding makes this a hypertensive emergency rather than urgency?
- An isolated elevated reading with no symptoms
- Acute end-organ damage such as pulmonary edema
- Mild headache alone
- A family history of hypertension
Correct answer: Acute end-organ damage such as pulmonary edema
Acute end-organ damage such as pulmonary edema is the answer. The distinguishing feature of a hypertensive emergency is evidence of acute target-organ injury, including pulmonary edema, encephalopathy, or renal failure, accompanying the severe pressure elevation. This warrants prompt, carefully controlled reduction of blood pressure.
- A 6-month-old infant is noted to have weak femoral pulses and a blood pressure higher in the arms than the legs. Beyond imaging the aorta, which condition explains the discrepancy and is the most likely diagnosis?
- Atrial septal defect
- Tricuspid regurgitation
- Patent ductus arteriosus
- Coarctation of the aorta
Correct answer: Coarctation of the aorta
Coarctation of the aorta is the answer. Narrowing of the aorta produces higher pressures and stronger pulses in the upper body with weak femoral pulses and lower-extremity pressures. This brachial-femoral discrepancy is the hallmark of the coarctation.
- A patient with chest pain has serial electrocardiograms, and the first one is nondiagnostic. Which feature on a follow-up tracing would most specifically indicate evolving transmural injury rather than ischemia alone?
- An isolated premature atrial contraction
- A prolonged PR interval
- New ST-segment elevation in contiguous leads
- Sinus tachycardia
Correct answer: New ST-segment elevation in contiguous leads
New ST-segment elevation in contiguous leads is the answer. Evolving ST elevation across anatomically contiguous leads signals transmural myocardial injury and prompts emergent reperfusion. Sinus tachycardia and an isolated premature beat are nonspecific and do not localize injury.
- A patient recovering from myocardial infarction is counseled on secondary prevention. Which combination of measures forms the foundation of reducing recurrent cardiovascular events?
- Antiplatelet therapy, statin, smoking cessation, and blood pressure control
- Avoiding all physical activity permanently
- Routine prophylactic antibiotics
- Bed rest and sodium loading
Correct answer: Antiplatelet therapy, statin, smoking cessation, and blood pressure control
Antiplatelet therapy, statin, smoking cessation, and blood pressure control is the answer. Secondary prevention after myocardial infarction centers on antiplatelet agents, lipid lowering with statins, tobacco cessation, and blood pressure management, along with cardiac rehabilitation. These measures together reduce recurrent events.
- A patient with chronic kidney disease is found to have peripheral edema and hypertension, and a renal cause is suspected. Which mechanism most directly links chronic kidney disease to elevated blood pressure?
- Sodium and fluid retention with activation of the renin-angiotensin system
- Excess thyroid hormone production
- A congenital septal defect
- Loss of pericardial compliance
Correct answer: Sodium and fluid retention with activation of the renin-angiotensin system
Sodium and fluid retention with activation of the renin-angiotensin system is the answer. Impaired kidneys retain sodium and water and inappropriately activate the renin-angiotensin system, raising blood pressure. This makes hypertension both a cause and a consequence of chronic kidney disease.
- A patient with severe symptomatic peripheral artery disease and a focal short stenosis in the superficial femoral artery has failed conservative therapy. Which intervention directly restores blood flow through the narrowed segment?
- Long-term bed rest
- Oral antibiotics
- Endovascular angioplasty with possible stenting
- Compression stockings
Correct answer: Endovascular angioplasty with possible stenting
Endovascular angioplasty with possible stenting is the answer. A focal arterial stenosis causing lifestyle-limiting symptoms despite medical therapy can be treated by catheter-based angioplasty and stenting to reopen the vessel. This directly restores perfusion in peripheral artery disease.
- A patient with acute chest pain is assessed for myocardial injury. Which feature of high-sensitivity cardiac troponin makes it especially useful for diagnosing myocardial infarction?
- It is only detectable two weeks after injury
- It is specific to skeletal muscle
- It is unaffected by myocardial damage
- It rises within a few hours of myocardial injury and is highly cardiac-specific
Correct answer: It rises within a few hours of myocardial injury and is highly cardiac-specific
It rises within a few hours of myocardial injury and is highly cardiac-specific is the answer. High-sensitivity troponin assays detect small amounts of cardiac-specific troponin released early after myocyte injury, enabling rapid diagnosis of myocardial infarction. Serial measurements help confirm a rising or falling pattern.
- A patient with a regular narrow-complex supraventricular tachycardia is hemodynamically unstable with hypotension and altered mental status. Which intervention is most appropriate?
- Carotid massage alone
- Synchronized cardioversion
- Oral beta-blocker
- Observation and reassurance
Correct answer: Synchronized cardioversion
Synchronized cardioversion is the answer. When a supraventricular tachycardia produces hemodynamic instability such as hypotension or altered mental status, immediate synchronized cardioversion is indicated. Pharmacologic measures and vagal maneuvers are reserved for stable patients.
- A previously healthy young adult develops acute heart failure and a friction rub days after a viral illness, with both myocardial and pericardial involvement suspected. This combined inflammation is best described as which condition?
- Atrial myxoma
- Myopericarditis
- Aortic stenosis
- Coarctation of the aorta
Correct answer: Myopericarditis
Myopericarditis is the answer. When a viral process inflames both the myocardium and the pericardium, the combined picture of heart failure or arrhythmia with a friction rub is termed myopericarditis. Management focuses on supportive care and treating the inflammation.
- A patient with an acute inferior myocardial infarction develops complete heart block with a junctional escape rhythm but remains hemodynamically stable. Which initial approach is most appropriate while monitoring for recovery?
- Immediate permanent pacemaker implantation regardless of stability
- Administration of adenosine
- High-dose beta-blocker therapy
- Close monitoring with atropine and transcutaneous pacing available if needed
Correct answer: Close monitoring with atropine and transcutaneous pacing available if needed
Close monitoring with atropine and transcutaneous pacing available if needed is the answer. Heart block complicating inferior infarction is often transient because of right coronary ischemia of the atrioventricular node, so stable patients are monitored with temporary measures ready. Permanent pacing is reserved for persistent or symptomatic block.
- A patient with chronic venous insufficiency is counseled on management to reduce edema and prevent ulceration. Which intervention is the cornerstone of conservative therapy?
- Strict prolonged standing
- Long-term anticoagulation
- Arterial bypass surgery
- Graduated compression stockings and leg elevation
Correct answer: Graduated compression stockings and leg elevation
Graduated compression stockings and leg elevation is the answer. Compression therapy counteracts venous hypertension and, together with leg elevation, reduces edema and promotes healing in chronic venous insufficiency. This conservative approach is the mainstay of management.
- A patient on the monitor in cardiac arrest shows a chaotic, disorganized waveform with no identifiable QRS complexes. Beyond beginning chest compressions, which intervention is most likely to restore an organized rhythm?
- Vagal maneuvers
- Synchronized cardioversion
- Oral antiarrhythmic loading
- Immediate defibrillation
Correct answer: Immediate defibrillation
Immediate defibrillation is the answer. Ventricular fibrillation produces a disorganized waveform without QRS complexes and is treated with prompt unsynchronized defibrillation alongside high-quality CPR. Synchronized cardioversion cannot be used without an organized QRS to target.
- A patient is found to have a wide-complex tachycardia, and clinicians must distinguish ventricular tachycardia from supraventricular tachycardia with aberrancy. Which historical feature most increases the likelihood that the rhythm is ventricular tachycardia?
- Presence of a delta wave at baseline
- Young age with no cardiac history
- A history of prior myocardial infarction or structural heart disease
- A normal echocardiogram with no scar
Correct answer: A history of prior myocardial infarction or structural heart disease
A history of prior myocardial infarction or structural heart disease is the answer. In a patient with a wide-complex tachycardia, underlying structural heart disease or prior infarction strongly favors ventricular tachycardia. When in doubt, a wide-complex tachycardia should be treated as ventricular tachycardia.
- A 32-year-old presents with well-demarcated erythematous plaques covered by thick silvery scale over both elbows and knees. When the scale is gently scraped away, pinpoint bleeding appears at the surface. Which condition does this finding most strongly support?
- Atopic dermatitis
- Seborrheic dermatitis
- Lichen planus
- Psoriasis
Correct answer: Psoriasis
Psoriasis is the answer. The well-demarcated plaques with silvery scale on extensor surfaces and the pinpoint bleeding when scale is removed, known as the Auspitz sign, are characteristic of this chronic papulosquamous disorder driven by accelerated keratinocyte turnover. Seborrheic dermatitis favors greasy scale in sebaceous areas rather than silvery plaques with Auspitz sign.
- A patient with extensive chronic plaque psoriasis covering more than 15 percent of the body surface has failed topical therapy and phototherapy. Which class of systemic agents targets the inflammatory cytokines that drive this disease?
- Topical calcineurin inhibitors
- Oral first-generation antihistamines
- Biologic agents targeting tumor necrosis factor or interleukin pathways
- Topical benzoyl peroxide
Correct answer: Biologic agents targeting tumor necrosis factor or interleukin pathways
Biologic agents targeting tumor necrosis factor or interleukin pathways is the answer. Moderate to severe psoriasis that fails topical and light therapy is treated with biologics that block cytokines such as tumor necrosis factor, interleukin-17, or interleukin-23, which drive the inflammatory cascade. Topical agents alone are inadequate for extensive disease.
- A 28-year-old develops new psoriatic plaques along a linear scratch mark where she recently injured her skin. Which phenomenon describes the appearance of psoriasis lesions at sites of trauma?
- Nikolsky sign
- Koebner phenomenon
- Darier sign
- Auspitz sign
Correct answer: Koebner phenomenon
The Koebner phenomenon is the answer. It describes the development of new psoriatic lesions at sites of skin trauma such as scratches, cuts, or sunburn, reflecting the disease's tendency to localize to injured skin. The Auspitz sign instead refers to pinpoint bleeding when scale is removed.
- A patient is being evaluated for a suspicious pigmented lesion. Which feature, as part of a widely used clinical screening mnemonic for melanoma, raises concern based on the lesion having two halves that do not match?
- Uniform color
- Symmetry
- Small diameter
- Asymmetry
Correct answer: Asymmetry
Asymmetry is the answer. In the ABCDE melanoma screening criteria, asymmetry means one half of the lesion does not match the other and is a warning sign of malignancy, along with border irregularity, color variation, diameter greater than 6 millimeters, and evolution. A symmetric, uniformly colored lesion is more reassuring.
- A 55-year-old has a newly enlarging dark lesion on the back with irregular borders and three different shades of brown and black. A biopsy confirms melanoma. Which histologic measurement is the single most important factor for determining prognosis?
- The diameter of the lesion in centimeters
- The color variation within the lesion
- The Breslow depth of tumor invasion
- The presence of overlying scale
Correct answer: The Breslow depth of tumor invasion
The Breslow depth of tumor invasion is the answer. The thickness of the melanoma measured in millimeters from the granular layer to the deepest tumor cell is the most powerful predictor of prognosis and guides surgical margins and staging. Surface features such as color and diameter do not determine outcome as reliably as depth.
- A clinician examining a patient notes a pigmented lesion that has changed in size, color, and shape over the past few months. Within the melanoma screening framework, which letter of the ABCDE criteria does this progressive change represent?
- Border
- Diameter
- Color
- Evolution
Correct answer: Evolution
Evolution is the answer. The E in the ABCDE melanoma criteria refers to evolution, meaning any change in a lesion's size, shape, color, or symptoms over time, and it is one of the most important warning signs of malignancy. A changing mole warrants prompt evaluation and biopsy.
- A 70-year-old fair-skinned man has a slowly growing pearly papule with a rolled, translucent border and overlying telangiectasias on the nose. The lesion occasionally bleeds. Which diagnosis is most likely?
- Seborrheic keratosis
- Basal cell carcinoma
- Actinic keratosis
- Dermatofibroma
Correct answer: Basal cell carcinoma
Basal cell carcinoma is the answer. A pearly or translucent papule with a rolled border, telangiectasias, and a tendency to bleed in a sun-exposed area of an older fair-skinned person is the classic presentation of the most common skin cancer. Seborrheic keratoses instead appear waxy and stuck-on without telangiectasias.
- A patient is diagnosed with a basal cell carcinoma on the cheek. Which statement best describes the typical biological behavior of this tumor?
- It frequently metastasizes early to distant organs
- It resolves spontaneously without treatment
- It is locally invasive but rarely metastasizes
- It primarily spreads through the bloodstream to the lungs
Correct answer: It is locally invasive but rarely metastasizes
It is locally invasive but rarely metastasizes is the answer. Basal cell carcinoma grows locally and can cause significant tissue destruction if neglected, but it almost never spreads to distant sites. This indolent behavior contrasts with melanoma, which carries a much higher metastatic risk.
- A 24-year-old started a new anticonvulsant two weeks ago and now has fever, painful skin, and a spreading rash with mucosal erosions of the lips and eyes. Several flat targetoid lesions have begun to blister and slough, involving about 7 percent of the body surface. Which condition is most likely?
- Stevens-Johnson syndrome
- Bullous impetigo
- Erythema nodosum
- Pityriasis rosea
Correct answer: Stevens-Johnson syndrome
Stevens-Johnson syndrome is the answer. A drug-triggered reaction with fever, painful skin, mucosal erosions, and epidermal detachment involving less than 10 percent of the body surface is characteristic of this severe mucocutaneous reaction. Detachment exceeding 30 percent would instead define toxic epidermal necrolysis.
- A patient is admitted with Stevens-Johnson syndrome attributed to a sulfonamide antibiotic. Which is the single most important initial step in management?
- Begin systemic antifungal therapy
- Immediately discontinue the offending medication
- Apply a high-potency topical retinoid
- Start oral isotretinoin
Correct answer: Immediately discontinue the offending medication
Immediately discontinuing the offending medication is the answer. The most critical action in Stevens-Johnson syndrome is prompt withdrawal of the causative drug, followed by supportive care such as fluid management, wound care, and treatment in a specialized unit. Delaying discontinuation worsens outcomes.
- A young adult has multiple oval, hypopigmented and slightly scaly macules on the upper back and chest that became more noticeable after sun exposure. A potassium hydroxide preparation shows short hyphae and round yeast forms resembling spaghetti and meatballs. Which organism is responsible?
- Trichophyton rubrum
- Candida albicans
- Sarcoptes scabiei
- Malassezia species
Correct answer: Malassezia species
Malassezia species is the answer. Tinea versicolor is caused by overgrowth of the lipophilic yeast Malassezia, producing hypopigmented or hyperpigmented scaly macules with the classic spaghetti-and-meatballs appearance on potassium hydroxide microscopy. The pigment changes often become more apparent after sun exposure.
- A patient with tinea versicolor on the trunk asks about treatment. Which therapy is appropriate first-line for limited disease?
- Topical antifungal such as selenium sulfide or ketoconazole
- Oral acyclovir
- Topical mupirocin
- Systemic corticosteroids
Correct answer: Topical antifungal such as selenium sulfide or ketoconazole
Topical antifungal such as selenium sulfide or ketoconazole is the answer. Limited tinea versicolor responds to topical antifungals like selenium sulfide, ketoconazole, or zinc pyrithione, which reduce the Malassezia yeast burden. Patients should be counseled that pigment changes may take weeks to normalize after the infection clears.
- A 16-year-old has comedones, inflammatory papules, and pustules across the forehead and cheeks. Which initial pathologic event underlies the formation of the comedones in this condition?
- Autoimmune attack on desmosomes
- Follicular hyperkeratinization plugging the pilosebaceous unit
- Viral infection of keratinocytes
- Deposition of immune complexes in vessel walls
Correct answer: Follicular hyperkeratinization plugging the pilosebaceous unit
Follicular hyperkeratinization plugging the pilosebaceous unit is the answer. Acne vulgaris begins with abnormal keratinization that obstructs the follicle, followed by sebum accumulation, Cutibacterium acnes proliferation, and inflammation. This plugging produces the comedones that are the earliest lesions of acne.
- A 19-year-old with moderate inflammatory acne has not improved despite topical retinoid and benzoyl peroxide use. Which is an appropriate next step in escalating therapy?
- Begin oral acyclovir
- Start systemic corticosteroids
- Add an oral antibiotic such as doxycycline
- Apply topical mupirocin
Correct answer: Add an oral antibiotic such as doxycycline
Adding an oral antibiotic such as doxycycline is the answer. Moderate inflammatory acne that fails topical therapy is commonly escalated with an oral tetracycline-class antibiotic, used alongside topical agents to reduce inflammation and bacterial load. Severe nodulocystic or refractory disease may later warrant isotretinoin.
- A patient with severe nodulocystic acne unresponsive to antibiotics is started on oral isotretinoin. Which counseling point is most critical before beginning this medication in a person who can become pregnant?
- It must be taken on an empty stomach to avoid toxicity
- It is highly teratogenic and requires strict pregnancy prevention
- It commonly causes permanent hearing loss
- It should be combined with tetracyclines for best effect
Correct answer: It is highly teratogenic and requires strict pregnancy prevention
It is highly teratogenic and requires strict pregnancy prevention is the answer. Isotretinoin causes severe birth defects, so patients who can become pregnant must use reliable contraception and undergo monitored pregnancy testing through a risk-management program. Combining it with tetracyclines is avoided because both can raise intracranial pressure.
- A 40-year-old develops an intensely itchy, erythematous, vesicular rash confined to a band on the wrist exactly where a new nickel watch contacts the skin. Which type of reaction does this localized pattern most likely represent?
- Irritant contact dermatitis
- Allergic contact dermatitis
- Atopic dermatitis
- Stasis dermatitis
Correct answer: Allergic contact dermatitis
Allergic contact dermatitis is the answer. A pruritic, vesicular eruption sharply limited to the area touching a known allergen such as nickel reflects a delayed type IV hypersensitivity reaction. The sharp geometric border matching the exposure distinguishes it from irritant dermatitis, which depends on the irritant's concentration and duration.
- A patient with recurrent hand dermatitis has an unclear allergen, and the clinician wants to identify the responsible substance. Which test is most appropriate to confirm an allergic contact dermatitis and its trigger?
- Patch testing
- Skin prick testing
- Wood lamp examination
- Tzanck smear
Correct answer: Patch testing
Patch testing is the answer. Allergic contact dermatitis is confirmed by patch testing, in which standardized allergens are applied to the back and read after several days to identify the delayed hypersensitivity trigger. Skin prick testing instead evaluates immediate, immunoglobulin E-mediated reactions rather than contact allergy.
- A 55-year-old presents with flaccid blisters that rupture easily, leaving painful erosions on the trunk and oral mucosa. Lateral pressure on adjacent normal-appearing skin causes the epidermis to shear away. Which autoantibody target underlies this disease?
- Hemidesmosomal BP180 and BP230
- Type VII collagen
- Desmoglein adhesion proteins
- Gliadin
Correct answer: Desmoglein adhesion proteins
Desmoglein adhesion proteins is the answer. Pemphigus vulgaris is caused by autoantibodies against desmogleins, which disrupt keratinocyte adhesion and produce flaccid intraepidermal blisters, mucosal involvement, and a positive Nikolsky sign. Antibodies to hemidesmosomal proteins instead cause bullous pemphigoid, which produces tense subepidermal blisters.
- A patient with flaccid blisters is examined, and the clinician applies gentle lateral pressure to perilesional skin, causing the superficial epidermis to slide off. Which sign does this maneuver demonstrate?
- Auspitz sign
- Darier sign
- Nikolsky sign
- Hutchinson sign
Correct answer: Nikolsky sign
Nikolsky sign is the answer. The shearing away of the superficial epidermis with lateral pressure on normal-appearing skin reflects loss of keratinocyte cohesion and is positive in pemphigus vulgaris and severe drug reactions such as toxic epidermal necrolysis. It contrasts with the tense, firmly adherent blisters of bullous pemphigoid.
- A 30-year-old develops crops of targetoid lesions with three concentric color zones on the palms and extensor extremities about ten days after a cold sore. Which infection most commonly precipitates this reaction?
- Herpes simplex virus
- Group A streptococcus
- Human papillomavirus
- Sarcoptes scabiei
Correct answer: Herpes simplex virus
Herpes simplex virus is the answer. Erythema multiforme is most often triggered by herpes simplex virus infection and presents with classic three-zone target lesions favoring the palms and extensor surfaces. Recognizing the preceding herpes outbreak helps confirm the diagnosis and guides suppressive therapy in recurrent cases.
- A patient is being evaluated for an eruption of target-shaped lesions. Which clinical feature best distinguishes erythema multiforme from early Stevens-Johnson syndrome?
- Presence of typical targetoid lesions on the extremities
- Limited mucosal involvement with little or no skin detachment
- A history of recent herpes infection
- Itching of the lesions
Correct answer: Limited mucosal involvement with little or no skin detachment
Limited mucosal involvement with little or no skin detachment is the answer. Erythema multiforme is usually self-limited with minimal mucosal disease and no significant epidermal sloughing, whereas Stevens-Johnson syndrome features extensive painful mucosal erosions and epidermal detachment. The degree of mucosal involvement and skin loss separates the benign from the life-threatening process.
- A 6-year-old has honey-colored crusted lesions around the nose and mouth that began as small vesicles. The child is otherwise well. Which organisms most commonly cause this superficial infection?
- Malassezia furfur and Candida albicans
- Herpes simplex virus and varicella-zoster virus
- Sarcoptes scabiei and Pediculus humanus
- Staphylococcus aureus and Streptococcus pyogenes
Correct answer: Staphylococcus aureus and Streptococcus pyogenes
Staphylococcus aureus and Streptococcus pyogenes is the answer. Nonbullous impetigo presents with honey-colored crusted lesions on the face and is caused by these gram-positive bacteria. Localized disease is treated with topical mupirocin, while more widespread involvement may require oral antibiotics.
- A 65-year-old has multiple tense, fluid-filled blisters on the trunk and flexural areas that do not rupture easily, and the surrounding skin does not shear with lateral pressure. Direct immunofluorescence shows linear deposition along the basement membrane. Which condition is most likely?
- Pemphigus vulgaris
- Dermatitis herpetiformis
- Bullous pemphigoid
- Porphyria cutanea tarda
Correct answer: Bullous pemphigoid
Bullous pemphigoid is the answer. Tense subepidermal blisters in an older adult, a negative Nikolsky sign, and linear basement-membrane immunofluorescence reflect autoantibodies against hemidesmosomal proteins. The tense, durable blisters and deeper cleavage plane distinguish it from the fragile, flaccid blisters of pemphigus vulgaris.
- A 5-year-old develops a unilateral cluster of grouped vesicles on an erythematous base in a band along one dermatome of the trunk, with associated pain. Reactivation of which latent virus explains this distribution?
- Varicella-zoster virus
- Coxsackievirus
- Molluscum contagiosum virus
- Human papillomavirus
Correct answer: Varicella-zoster virus
Varicella-zoster virus is the answer. Herpes zoster results from reactivation of latent varicella-zoster virus within a sensory ganglion, producing painful grouped vesicles confined to a single dermatome. Antiviral therapy started early reduces the duration and the risk of postherpetic neuralgia.
- A 70-year-old has a firm, rapidly growing, dome-shaped nodule with a central keratin-filled crater on the sun-exposed forearm, and biopsy shows atypical keratinocytes. Which malignancy is most consistent with these findings?
- Basal cell carcinoma
- Kaposi sarcoma
- Dermatofibroma
- Squamous cell carcinoma
Correct answer: Squamous cell carcinoma
Squamous cell carcinoma is the answer. A firm, scaly or crusted nodule, sometimes with a central keratin plug, arising on chronically sun-damaged skin and showing atypical keratinocytes is characteristic of cutaneous squamous cell carcinoma. Unlike basal cell carcinoma, it carries a higher potential for regional metastasis.
- An older patient has several rough, scaly, erythematous macules on the bald scalp and dorsal hands that feel like sandpaper. These lesions are considered precursors that can progress to which malignancy?
- Squamous cell carcinoma
- Melanoma
- Basal cell carcinoma
- Merkel cell carcinoma
Correct answer: Squamous cell carcinoma
Squamous cell carcinoma is the answer. Actinic keratoses are sun-induced precancerous lesions that feel gritty or sandpaper-like, and a subset progress to invasive squamous cell carcinoma over time. Treating them with cryotherapy or topical agents reduces this risk.
- A 3-year-old has intensely pruritic, ill-defined erythematous patches with scaling in the antecubital and popliteal flexures, and the family history includes asthma and allergic rhinitis. Which chronic condition is most likely?
- Psoriasis
- Tinea corporis
- Scabies
- Atopic dermatitis
Correct answer: Atopic dermatitis
Atopic dermatitis is the answer. Chronic, intensely itchy, poorly demarcated eczematous patches in flexural areas of a child with a personal or family history of atopy are classic for atopic dermatitis. Management centers on emollients, trigger avoidance, and topical anti-inflammatory therapy during flares.
- A patient has a single oval, salmon-colored plaque with a collarette of fine scale on the trunk, followed a week later by smaller similar lesions arranged along the skin cleavage lines in a Christmas-tree pattern. Which self-limited condition is most likely?
- Pityriasis rosea
- Secondary syphilis
- Tinea corporis
- Guttate psoriasis
Correct answer: Pityriasis rosea
Pityriasis rosea is the answer. A single herald patch followed by smaller oval lesions oriented along skin cleavage lines in a Christmas-tree distribution is the hallmark of this self-limited eruption. Because secondary syphilis can mimic it, especially with palmar or soles involvement, serologic testing is considered when the presentation is atypical.
- A 26-year-old man with type 1 diabetes presents in diabetic ketoacidosis with a serum glucose of 510 mg/dL, a measured sodium of 128 mmol/L, and severe hyperglycemia. Before assuming he has true hyponatremia, what should the clinician do with this sodium value?
- Treat the low sodium with hypertonic saline immediately
- Restrict all sodium intake
- Assume it reflects the syndrome of inappropriate antidiuretic hormone
- Correct the measured sodium upward for the degree of hyperglycemia
Correct answer: Correct the measured sodium upward for the degree of hyperglycemia
Correcting the measured sodium upward for the degree of hyperglycemia is the right step in diabetic ketoacidosis. High glucose draws water into the vascular space and dilutes the measured sodium, so the true corrected sodium is higher than the reported value. Giving hypertonic saline for this artifactual low sodium is dangerous, sodium restriction is not indicated, and the dilutional pattern is not the syndrome of inappropriate antidiuretic hormone.
- During recovery from diabetic ketoacidosis, the anion gap has closed, the patient is eating, and the clinician plans to transition off the insulin infusion. Which step prevents rebound ketoacidosis during the changeover?
- Overlap subcutaneous basal insulin with the infusion before stopping the drip
- Stop the infusion and wait several hours before any subcutaneous insulin
- Switch directly to an oral hypoglycemic agent
- Discontinue insulin entirely once the patient eats
Correct answer: Overlap subcutaneous basal insulin with the infusion before stopping the drip
Overlapping subcutaneous basal insulin with the infusion before stopping the drip prevents rebound ketoacidosis. Intravenous insulin clears within minutes, so a basal dose must be active before the infusion ends to avoid a gap in coverage that allows ketogenesis to resume. Waiting hours after stopping leaves the patient uncovered, oral agents act too slowly and are wrong for type 1 disease, and discontinuing insulin entirely invites recurrent ketoacidosis.
- A 58-year-old woman with autoimmune hypothyroidism reports persistent fatigue, and her clinician wants the single best test to monitor the adequacy of her levothyroxine dose. Which test serves this purpose in primary hypothyroidism?
- Total triiodothyronine
- Thyroglobulin
- Serum thyroid-stimulating hormone
- Anti-thyroid peroxidase antibody titer
Correct answer: Serum thyroid-stimulating hormone
Serum thyroid-stimulating hormone is the single best test to monitor levothyroxine adequacy in primary hypothyroidism. Because the pituitary is intact, thyrotropin sensitively reflects whether the replacement dose is too low, correct, or excessive, and the goal is a normalized value. Total triiodothyronine does not track replacement well, thyroglobulin is used in thyroid cancer surveillance, and antibody titers confirm autoimmune cause but do not guide dosing.
- A 44-year-old woman with Graves ophthalmopathy has worsening eye protrusion, double vision, and a complaint of redness and grittiness while being treated for hyperthyroidism. Which modifiable factor most clearly worsens the eye disease and should be addressed?
- Moderate caffeine intake
- Cigarette smoking
- A high-fiber diet
- Regular aerobic exercise
Correct answer: Cigarette smoking
Cigarette smoking most clearly worsens Graves ophthalmopathy and should be addressed. Smoking is the strongest modifiable risk factor for progression and severity of the eye disease, so cessation is an important part of management. Moderate caffeine, a high-fiber diet, and regular exercise do not drive the orbital inflammation of Graves eye disease.
- A 35-year-old woman has heat intolerance, weight loss, and a suppressed thyroid-stimulating hormone, and her clinician explains how thyroid hormone is normally regulated. Which feedback relationship is correct in a healthy person?
- High thyroid hormone stimulates more thyroid-stimulating hormone release
- High thyroid hormone suppresses thyroid-stimulating hormone via negative feedback
- Thyroid-stimulating hormone is produced by the adrenal gland
- Thyroid hormone has no effect on the pituitary
Correct answer: High thyroid hormone suppresses thyroid-stimulating hormone via negative feedback
High thyroid hormone suppresses thyroid-stimulating hormone through negative feedback, which is the correct relationship and explains why the thyrotropin is low when thyroid hormone is high. Circulating thyroxine and triiodothyronine feed back on the pituitary and hypothalamus to reduce thyrotropin output. High thyroid hormone does not stimulate more thyrotropin, thyrotropin comes from the pituitary not the adrenal, and thyroid hormone clearly acts on the pituitary.
- A 30-year-old woman in her first trimester of pregnancy has a mildly suppressed thyroid-stimulating hormone, a slightly elevated free thyroxine, no goiter or eye signs, and resolution of mild nausea, with normal findings by mid-pregnancy. Which explanation best fits this transient pattern?
- New Graves disease requiring radioactive iodine
- Toxic multinodular goiter
- Hashimoto thyroiditis
- Gestational transient thyrotoxicosis from human chorionic gonadotropin stimulation
Correct answer: Gestational transient thyrotoxicosis from human chorionic gonadotropin stimulation
Gestational transient thyrotoxicosis from human chorionic gonadotropin stimulation best fits this transient pattern. The structural similarity of human chorionic gonadotropin to thyrotropin can mildly stimulate the thyroid in early pregnancy, producing a slightly suppressed thyrotropin that resolves as the hormone falls. Graves disease would have eye signs and persistent stimulating antibodies, radioactive iodine is contraindicated in pregnancy, and a toxic goiter and Hashimoto thyroiditis do not show this self-limited early-pregnancy course.
- A patient newly started on levothyroxine for hypothyroidism has known coronary artery disease, and the clinician chooses an initial dosing approach. Which strategy is most appropriate to avoid precipitating angina?
- Start a low dose and titrate up gradually
- Begin a full weight-based replacement dose at once
- Use intravenous thyroid hormone boluses
- Combine high-dose thyroid hormone with a stimulant
Correct answer: Start a low dose and titrate up gradually
Starting a low dose and titrating up gradually is most appropriate in a hypothyroid patient with coronary artery disease. Thyroid hormone increases myocardial oxygen demand, so a slow upward titration avoids provoking angina or ischemia. A full replacement dose started at once can precipitate cardiac events, intravenous boluses are unnecessary and risky here, and pairing thyroid hormone with a stimulant adds cardiac strain.
- A patient with primary adrenal insufficiency who takes daily glucocorticoid replacement is scheduled for major surgery. Which adjustment to the glucocorticoid regimen is required to prevent an adrenal crisis perioperatively?
- Hold the glucocorticoid on the day of surgery
- Replace the glucocorticoid with insulin
- No change is needed for surgery
- Administer increased stress-dose glucocorticoids around the procedure
Correct answer: Administer increased stress-dose glucocorticoids around the procedure
Administering increased stress-dose glucocorticoids around the procedure is required to prevent an adrenal crisis. A patient who cannot mount an endogenous cortisol surge needs supplemental steroid to meet the heightened demand of surgical stress. Holding the dose would risk crisis, insulin does not substitute for cortisol, and making no change leaves the patient unable to respond to the stress.
- A 33-year-old woman with primary adrenal insufficiency reports that she sometimes feels weak and craves salt, and she asks why she needs both a glucocorticoid and a mineralocorticoid. Which physiologic role does the mineralocorticoid replacement serve?
- It raises blood glucose during stress
- It suppresses the thyroid
- It maintains sodium retention and potassium balance
- It replaces growth hormone
Correct answer: It maintains sodium retention and potassium balance
The mineralocorticoid replacement maintains sodium retention and potassium balance, which is why it is needed alongside the glucocorticoid in primary adrenal insufficiency. Loss of aldosterone causes sodium and water wasting, salt craving, and potassium retention, all corrected by mineralocorticoid replacement. Raising glucose during stress is the glucocorticoid's role, and the mineralocorticoid does not suppress the thyroid or replace growth hormone.
- A 50-year-old man with Cushing syndrome is undergoing localization, and high-dose dexamethasone suppresses his cortisol while ACTH is elevated. Which source of cortisol excess does this pattern most support?
- A pituitary ACTH-secreting adenoma (Cushing disease)
- A primary adrenal adenoma
- An ectopic ACTH-secreting small cell lung tumor
- Exogenous steroid use
Correct answer: A pituitary ACTH-secreting adenoma (Cushing disease)
A pituitary ACTH-secreting adenoma, the entity called Cushing disease, is most supported. Pituitary tumors typically retain some sensitivity to glucocorticoid feedback, so cortisol suppresses with a high dexamethasone dose while ACTH is elevated. A primary adrenal source and exogenous steroids would show low ACTH, and ectopic ACTH from a lung tumor characteristically fails to suppress even at high doses.
- A patient with episodic hypertension is diagnosed with a pheochromocytoma and started on alpha-blockade in preparation for surgery. Which finding indicates that adequate alpha-blockade has been achieved before adding any other agent?
- Development of mild orthostatic blood pressure changes
- A rising fasting glucose
- A new resting bradycardia
- An increase in serum potassium
Correct answer: Development of mild orthostatic blood pressure changes
Development of mild orthostatic blood pressure changes indicates adequate alpha-blockade before pheochromocytoma surgery. Effective blockade of catecholamine-driven vasoconstriction relaxes the vasculature enough to produce slight postural drops, signaling readiness to proceed. A rising glucose, a resting bradycardia, and a rise in potassium are not the markers used to confirm sufficient alpha-blockade.
- A 12-year-old boy with a family history of bilateral pheochromocytoma, mucosal neuromas, and a marfanoid body habitus is found to have medullary thyroid carcinoma. Which inherited syndrome best unifies these specific features?
- Multiple endocrine neoplasia type 1
- Von Hippel-Lindau disease
- Multiple endocrine neoplasia type 2B
- Neurofibromatosis type 1
Correct answer: Multiple endocrine neoplasia type 2B
Multiple endocrine neoplasia type 2B best unifies these features. This syndrome classically combines medullary thyroid carcinoma, pheochromocytoma, mucosal neuromas, and a marfanoid habitus, distinguishing it from related disorders. Multiple endocrine neoplasia type 1 involves parathyroid, pituitary, and pancreatic tumors instead, and while pheochromocytoma occurs in von Hippel-Lindau disease and neurofibromatosis type 1, neither features mucosal neuromas with medullary thyroid carcinoma.
- A 48-year-old man with acromegaly is counseled about the increased health risks of untreated growth hormone excess. Which complication is a leading cause of premature death in acromegaly that warrants close monitoring?
- Iron deficiency anemia
- Vitamin C deficiency
- Cardiovascular disease
- Acute appendicitis
Correct answer: Cardiovascular disease
Cardiovascular disease is a leading cause of premature death in acromegaly and warrants close monitoring. Chronic growth hormone excess promotes hypertension, cardiomyopathy, and accelerated atherosclerosis that shorten life expectancy if untreated. Iron deficiency anemia, vitamin C deficiency, and acute appendicitis are not the characteristic mortality drivers of this disease.
- A patient with acromegaly from a pituitary macroadenoma is not cured after transsphenoidal surgery and has persistent elevation of insulin-like growth factor 1. Which medical therapy directly reduces growth hormone secretion as a next step?
- Levothyroxine
- Insulin
- A thiazide diuretic
- A somatostatin analog such as octreotide
Correct answer: A somatostatin analog such as octreotide
A somatostatin analog such as octreotide directly reduces growth hormone secretion and is an appropriate next step after incomplete surgical cure of acromegaly. Somatostatin physiologically inhibits growth hormone release, so its analogs lower hormone levels and insulin-like growth factor 1. Levothyroxine, insulin, and a thiazide diuretic do not suppress growth hormone.
- A 55-year-old woman with primary hyperparathyroidism and hypercalcemia is referred for evaluation of bone effects. Which skeletal pattern is most characteristic of long-standing parathyroid hormone excess?
- Subperiosteal bone resorption
- Increased cortical bone density
- Dense sclerotic vertebrae
- No effect on bone
Correct answer: Subperiosteal bone resorption
Subperiosteal bone resorption is most characteristic of long-standing parathyroid hormone excess. Excess hormone drives osteoclastic resorption, classically seen along the radial aspect of the phalanges, and contributes to reduced cortical bone density. The hormone reduces rather than increases cortical density, does not produce dense sclerotic vertebrae, and clearly affects bone.
- A patient with severe symptomatic hypercalcemia from primary hyperparathyroidism is hospitalized and remains hypercalcemic despite saline hydration. Which agent provides more sustained lowering of calcium by inhibiting osteoclastic bone resorption?
- Oral calcium carbonate
- A thiazide diuretic
- Vitamin D
- A bisphosphonate
Correct answer: A bisphosphonate
A bisphosphonate provides more sustained lowering of calcium by inhibiting osteoclastic bone resorption in severe hypercalcemia. After volume repletion, blocking bone breakdown reduces calcium release over the following days. Oral calcium and vitamin D would raise calcium further, and a thiazide diuretic increases calcium and is contraindicated in hypercalcemia.
- A patient with acute symptomatic hypocalcemia after thyroid surgery has carpopedal spasm and a prolonged QT interval on the electrocardiogram. Which treatment most rapidly relieves the acute neuromuscular symptoms?
- Oral vitamin D alone over several days
- A loop diuretic
- Intravenous calcium gluconate
- Oral phosphate
Correct answer: Intravenous calcium gluconate
Intravenous calcium gluconate most rapidly relieves acute symptomatic hypocalcemia. Replacing calcium directly reverses the neuromuscular irritability causing carpopedal spasm and shortens the dangerously prolonged QT interval. Oral vitamin D works too slowly for an acute crisis, a loop diuretic lowers calcium further, and oral phosphate would worsen hypocalcemia.
- A 40-year-old man with central diabetes insipidus is comparing his condition to the syndrome of inappropriate antidiuretic hormone, which a relative has. Which contrasting laboratory pattern best characterizes his diabetes insipidus?
- Low serum sodium with concentrated urine
- Normal sodium with no urine output
- Low sodium with no thirst
- High serum sodium with inappropriately dilute urine
Correct answer: High serum sodium with inappropriately dilute urine
High serum sodium with inappropriately dilute urine best characterizes diabetes insipidus. The deficiency of, or resistance to, antidiuretic hormone causes loss of large volumes of dilute urine, concentrating the blood and raising serum sodium. Low sodium with concentrated urine is the opposite picture seen in the syndrome of inappropriate antidiuretic hormone, and the other patterns do not fit the polyuric, water-wasting state.
- A 29-year-old woman who is breastfeeding has a known prolactinoma that was stable, and she asks how nursing relates to her prolactin. Which statement about prolactin physiology is correct?
- Prolactin suppresses milk production
- Suckling stimulates prolactin release and milk production
- Prolactin is secreted by the adrenal gland
- Dopamine increases prolactin secretion
Correct answer: Suckling stimulates prolactin release and milk production
Suckling stimulates prolactin release and milk production, which is the correct statement about prolactin physiology. The infant's suckling triggers a neural reflex that increases prolactin, sustaining lactation. Prolactin promotes rather than suppresses milk production, it is secreted by the pituitary not the adrenal gland, and dopamine inhibits rather than increases prolactin.
- A 62-year-old man with type 2 diabetes has an estimated GFR that has fallen to 28 mL/min/1.73 m2. The clinician reviews his glucose-lowering regimen. Which commonly used agent should be discontinued at this level of kidney function because of accumulation risk?
- A short-acting basal insulin
- A GLP-1 receptor agonist if tolerated
- Dietary modification
- Metformin
Correct answer: Metformin
Metformin should be discontinued at this level of kidney function because of accumulation risk. As the estimated GFR falls below the recommended threshold, metformin can build up and raise the risk of lactic acidosis, so it is stopped in advanced kidney impairment. Insulin can be continued with dose adjustment, dietary modification remains appropriate, and a GLP-1 receptor agonist may still be used per its renal labeling.
- A patient with newly diagnosed type 2 diabetes is overweight, and the clinician explains why insulin resistance is central to the disease. Which description best captures the core defect in type 2 diabetes?
- Autoimmune destruction of beta cells
- Reduced tissue responsiveness to insulin with relative insulin deficiency
- Complete absence of insulin from birth
- Deficiency of antidiuretic hormone
Correct answer: Reduced tissue responsiveness to insulin with relative insulin deficiency
Reduced tissue responsiveness to insulin with relative insulin deficiency best captures the core defect of type 2 diabetes. Peripheral tissues resist insulin while the pancreas cannot fully compensate, producing hyperglycemia. Autoimmune beta cell destruction and a complete absence of insulin describe type 1 diabetes, and antidiuretic hormone deficiency defines diabetes insipidus, a distinct disorder.
- A 19-year-old woman with newly diagnosed type 1 diabetes has well-controlled glucose with low insulin requirements in the weeks after starting therapy, and the clinician explains this is temporary. Which phase does this describe?
- Established hyperosmolar state
- The dawn phenomenon
- The honeymoon (partial remission) phase
- Complete pancreatic recovery
Correct answer: The honeymoon (partial remission) phase
This describes the honeymoon, or partial remission, phase of type 1 diabetes. After starting insulin, residual beta cell function can transiently improve, lowering insulin needs, but the phase is temporary as autoimmune destruction continues. It is not a hyperosmolar state, the dawn phenomenon refers to morning hyperglycemia, and it does not represent permanent pancreatic recovery.
- A 45-year-old woman with hypothyroidism is found to also have vitiligo and pernicious anemia, and the clinician notes a clustering of autoimmune endocrine conditions. Which combination is characteristic of autoimmune polyglandular syndrome type 2?
- Pheochromocytoma and medullary thyroid cancer
- Adrenal insufficiency, autoimmune thyroid disease, and type 1 diabetes
- Acromegaly and prolactinoma
- Primary hyperaldosteronism and Cushing syndrome
Correct answer: Adrenal insufficiency, autoimmune thyroid disease, and type 1 diabetes
Adrenal insufficiency, autoimmune thyroid disease, and type 1 diabetes are characteristic of autoimmune polyglandular syndrome type 2. This adult-onset clustering of organ-specific autoimmune endocrine disorders often co-occurs with conditions such as vitiligo and pernicious anemia. Pheochromocytoma with medullary thyroid cancer reflects multiple endocrine neoplasia, and the other pairings are not the defining triad of this polyglandular syndrome.
- A 38-year-old woman with Hashimoto thyroiditis is counseled that her condition raises her risk of a specific, though uncommon, thyroid malignancy. Which lymphoid malignancy is associated with chronic Hashimoto thyroiditis?
- Anaplastic thyroid carcinoma
- Follicular thyroid carcinoma
- Primary thyroid lymphoma
- Parathyroid carcinoma
Correct answer: Primary thyroid lymphoma
Primary thyroid lymphoma is the malignancy associated with chronic Hashimoto thyroiditis. The longstanding lymphocytic infiltration of the gland is the recognized risk factor for this uncommon lymphoid cancer, classically suspected when a goiter enlarges rapidly. Anaplastic and follicular carcinomas and parathyroid carcinoma are not the malignancy specifically linked to Hashimoto disease.
- A patient with subclinical hyperthyroidism has a persistently suppressed thyroid-stimulating hormone with normal free thyroxine and triiodothyronine. The clinician explains the main long-term risks if it is left untreated in an older adult. Which complications are of greatest concern?
- Atrial fibrillation and bone loss
- Hyperkalemia and kidney stones
- Anemia and weight gain
- Hypoglycemia and seizures
Correct answer: Atrial fibrillation and bone loss
Atrial fibrillation and bone loss are of greatest concern in untreated subclinical hyperthyroidism in older adults. Even a low-level excess of thyroid activity, reflected by a suppressed thyrotropin with normal hormone levels, increases the risk of this arrhythmia and accelerates loss of bone density. Hyperkalemia, kidney stones, anemia, weight gain, hypoglycemia, and seizures are not the characteristic risks of this state.
- A 60-year-old man with weight loss and a new firm thyroid nodule undergoes fine-needle aspiration that returns as suspicious for follicular neoplasm, which cannot distinguish benign from malignant on cytology alone. Which step is needed to determine whether follicular carcinoma is present?
- Repeat the same fine-needle aspiration only
- Surgical excision to assess for capsular or vascular invasion
- A thyroid-stimulating hormone level alone
- Start levothyroxine and observe
Correct answer: Surgical excision to assess for capsular or vascular invasion
Surgical excision to assess for capsular or vascular invasion is needed to determine whether follicular carcinoma is present. Follicular cancer is diagnosed by demonstrating invasion through the capsule or into vessels, which cytology cannot show, so histologic examination of the resected tissue is required. Repeating the aspiration faces the same limitation, a thyrotropin level does not establish malignancy, and observation on levothyroxine would delay diagnosis.
- A patient with poorly controlled diabetes and ketoacidosis develops facial pain, black eschar in the nasal cavity, and orbital swelling. Which life-threatening infection is most strongly associated with the acidotic, hyperglycemic state?
- Allergic rhinitis
- Viral pharyngitis
- Rhinocerebral mucormycosis
- Bacterial conjunctivitis
Correct answer: Rhinocerebral mucormycosis
Rhinocerebral mucormycosis is most strongly associated with the acidotic, hyperglycemic state of diabetic ketoacidosis. The low pH and high glucose favor this angioinvasive mold, which produces facial pain, black necrotic nasal eschar, and orbital involvement and requires emergent treatment. Allergic rhinitis, viral pharyngitis, and bacterial conjunctivitis do not have this specific link to the ketoacidotic diabetic patient.
- A patient with diabetes is found to have a fasting glucose of 60 mg/dL in clinic but is entirely asymptomatic and feels well, with no medications that lower glucose. Which step is most appropriate before diagnosing a hypoglycemic disorder?
- Immediately start frequent feedings
- Begin a continuous dextrose infusion
- Refer for pancreatic surgery
- Confirm true hypoglycemia by documenting the Whipple triad
Correct answer: Confirm true hypoglycemia by documenting the Whipple triad
Confirming true hypoglycemia by documenting the Whipple triad is most appropriate before diagnosing a hypoglycemic disorder. The triad of low measured glucose, consistent symptoms, and relief with glucose correction establishes that a low reading is clinically meaningful rather than artifactual. Starting feedings or a dextrose infusion and referring for surgery are premature without first confirming genuine, symptomatic hypoglycemia.
- A 30-year-old woman is found to have a thyroid-stimulating hormone that is inappropriately normal or elevated despite a high free thyroxine and ongoing hyperthyroid symptoms, with no exogenous hormone use. Which uncommon cause should be considered?
- A thyroid-stimulating hormone-secreting pituitary adenoma
- Primary hypothyroidism
- Iodine deficiency
- Subacute thyroiditis
Correct answer: A thyroid-stimulating hormone-secreting pituitary adenoma
A thyroid-stimulating hormone-secreting pituitary adenoma should be considered. When thyroid hormone is elevated but the thyrotropin is inappropriately normal or high rather than suppressed, an autonomously secreting pituitary tumor that drives the thyroid is a recognized cause. Primary hypothyroidism and iodine deficiency lower thyroid hormone, and subacute thyroiditis suppresses thyrotropin during its hyperthyroid phase.
- A patient with type 1 diabetes asks how glucagon helps during a severe hypoglycemic episode when she cannot swallow. Which physiologic action of glucagon makes it useful as rescue therapy?
- It stimulates insulin release
- It promotes hepatic glycogen breakdown to raise blood glucose
- It lowers blood glucose
- It increases urinary glucose loss
Correct answer: It promotes hepatic glycogen breakdown to raise blood glucose
Glucagon promotes hepatic glycogen breakdown to raise blood glucose, which makes it useful as rescue therapy for severe hypoglycemia when oral intake is impossible. By mobilizing stored hepatic glycogen, it quickly raises the blood sugar. Glucagon does not stimulate insulin release, does not lower glucose, and does not increase urinary glucose loss.
- A patient with chronic, stable type 2 diabetes is reviewed for cardiovascular risk reduction, and the clinician sets a blood pressure and lipid plan. Beyond glucose control, which intervention most reduces cardiovascular events in a diabetic patient with hypertension?
- Blood pressure control and statin therapy
- Ignoring blood pressure if glucose is controlled
- High-dose vitamin supplements
- Routine bed rest
Correct answer: Blood pressure control and statin therapy
Blood pressure control and statin therapy most reduce cardiovascular events in a diabetic patient with hypertension. Because much of the morbidity in diabetes is cardiovascular, lowering blood pressure and treating dyslipidemia provide substantial protection alongside glucose management. Ignoring blood pressure, taking high-dose vitamins, and bed rest do not provide this benefit.
- A patient with longstanding type 2 diabetes presents with confusion and a fingerstick glucose of 42 mg/dL and is able to swallow safely. Which is the most appropriate immediate treatment?
- An immediate dose of insulin
- A bisphosphonate
- A beta-blocker
- Oral fast-acting carbohydrate such as glucose tablets or juice
Correct answer: Oral fast-acting carbohydrate such as glucose tablets or juice
Oral fast-acting carbohydrate such as glucose tablets or juice is the most appropriate immediate treatment for symptomatic hypoglycemia in a patient who can swallow safely. Rapidly absorbed carbohydrate quickly raises the blood glucose and relieves the neuroglycopenic symptoms. Insulin would dangerously lower glucose further, and a bisphosphonate and a beta-blocker have no role in treating acute hypoglycemia.
- A 45-year-old woman with Cushing syndrome from an adrenal adenoma undergoes successful removal of the affected adrenal gland. In the immediate postoperative period, why does she require glucocorticoid replacement?
- She now has hyperthyroidism
- The remaining adrenal is suppressed and cannot yet produce adequate cortisol
- She has developed diabetes insipidus
- Her parathyroid glands were removed
Correct answer: The remaining adrenal is suppressed and cannot yet produce adequate cortisol
The remaining adrenal is suppressed and cannot yet produce adequate cortisol, which is why she requires glucocorticoid replacement after removal of a cortisol-secreting adenoma. Chronic cortisol excess had suppressed ACTH and the contralateral gland, so until that axis recovers, supplemental steroid prevents adrenal insufficiency. The surgery does not cause hyperthyroidism or diabetes insipidus, and the parathyroid glands are not involved.
- A patient with a large nonfunctioning pituitary macroadenoma reports progressive loss of peripheral vision in both temporal fields. Which structure compressed by the tumor explains this specific visual defect?
- The oculomotor nerve
- The optic chiasm
- The cochlea
- The trigeminal ganglion
Correct answer: The optic chiasm
Compression of the optic chiasm explains the loss of peripheral vision in both temporal fields. A pituitary macroadenoma growing upward presses on the crossing nasal retinal fibers at the chiasm, producing the classic bitemporal visual field defect. The oculomotor nerve governs eye movements, the cochlea serves hearing, and the trigeminal ganglion carries facial sensation, none of which create this field pattern.
- A patient with a pituitary adenoma is found to have low free thyroxine together with a low or inappropriately normal thyroid-stimulating hormone. Which type of hypothyroidism does this laboratory pattern indicate?
- Secondary (central) hypothyroidism
- Primary hypothyroidism
- Subclinical hyperthyroidism
- Euthyroid sick syndrome resolution
Correct answer: Secondary (central) hypothyroidism
Secondary, or central, hypothyroidism is indicated by a low free thyroxine with a low or inappropriately normal thyroid-stimulating hormone. When the pituitary fails to drive the thyroid, the thyrotropin does not rise as it should despite the low thyroid hormone. Primary hypothyroidism shows a clearly elevated thyrotropin, subclinical hyperthyroidism has a suppressed thyrotropin with normal hormone, and the pattern is not explained by resolving sick euthyroid state.
- A 50-year-old reports recurrent transient episodes of complete vision loss in one eye, each lasting a few minutes and resolving fully, described as a curtain coming down and then lifting. He has carotid bruits. Which term best describes these transient monocular episodes that may precede a central retinal artery occlusion?
- Diplopia
- Metamorphopsia
- Amaurosis fugax
- Scotoma scintillans
Correct answer: Amaurosis fugax
Amaurosis fugax is the answer. Transient, painless monocular vision loss that fully resolves, often described as a descending curtain, reflects temporary retinal ischemia from emboli and serves as a warning sign that precedes a central retinal artery occlusion or stroke. Metamorphopsia is distortion of straight lines, diplopia is double vision from misalignment, and scintillating scotoma is the visual aura of migraine rather than transient ischemic vision loss.
- A clinician evaluates a 68-year-old with sudden painless monocular vision loss and suspects a central retinal artery occlusion. On dilated fundoscopy, which additional finding besides a cherry-red spot would support arterial rather than venous occlusion?
- Diffuse blot hemorrhages in all four quadrants
- Box-carring or segmentation of the retinal arterioles
- Optic disc swelling with peripapillary hemorrhages
- Dilated tortuous veins with cotton-wool spots throughout
Correct answer: Box-carring or segmentation of the retinal arterioles
Box-carring or segmentation of the retinal arterioles is correct. In central retinal artery occlusion the columns of blood within the arterioles break into segments, called box-carring, reflecting stagnant arterial flow alongside the pale retina and cherry-red macula. Diffuse four-quadrant hemorrhages with dilated tortuous veins describe a central retinal vein occlusion, and isolated disc swelling reflects optic neuropathy rather than arterial occlusion.
- A clinician describes acute angle closure glaucoma to a student and explains the underlying mechanism. Which physiologic event most directly produces the abrupt rise in intraocular pressure?
- Excess production of tears by the lacrimal gland
- Detachment of the neurosensory retina from the pigment epithelium
- Opacification of the crystalline lens
- Blockage of aqueous humor outflow at a narrowed iridocorneal angle
Correct answer: Blockage of aqueous humor outflow at a narrowed iridocorneal angle
Blockage of aqueous humor outflow at a narrowed iridocorneal angle is correct. In acute angle closure glaucoma the peripheral iris obstructs the trabecular meshwork, abruptly trapping aqueous humor and spiking intraocular pressure, which threatens the optic nerve. Excess tearing relates to lacrimal drainage, retinal detachment is a separate posterior event, and lens opacification describes a cataract rather than the outflow obstruction of angle closure.
- A patient with intermittent eye pain and halos is found to have anatomically narrow angles and is at risk for acute angle closure glaucoma. Which class of systemic medication is most important to use cautiously because it can precipitate an acute attack by dilating the pupil?
- Beta-lactam antibiotics
- Anticholinergic agents
- Thiazide diuretics
- Proton pump inhibitors
Correct answer: Anticholinergic agents
Anticholinergic agents are the answer. Drugs with anticholinergic activity dilate the pupil, which can push the peripheral iris into a narrow angle and trigger acute angle closure glaucoma in predisposed eyes. Beta-lactam antibiotics, thiazide diuretics, and proton pump inhibitors do not cause the pupillary dilation that precipitates angle closure.
- A 62-year-old is incidentally found on screening to have an elevated intraocular pressure, an enlarged optic cup-to-disc ratio, and gradual loss of peripheral vision in both eyes, while the central vision and the anterior chamber angle remain normal and the eyes are painless. Which is the most likely diagnosis?
- Acute angle closure glaucoma
- Anterior uveitis
- Primary open-angle glaucoma
- Episcleritis
Correct answer: Primary open-angle glaucoma
Primary open-angle glaucoma is the answer. Painless, gradual peripheral visual field loss with an enlarged cup-to-disc ratio and elevated pressure in an open angle is the classic chronic glaucoma that often goes unnoticed until advanced. Acute angle closure is acutely painful with a closed angle, and uveitis and episcleritis present with redness and inflammation rather than silent optic nerve cupping.
- A 7-year-old recovering from a cold presents with one day of red eyes and crusting. The clinician must distinguish bacterial conjunctivitis from a viral cause to decide on topical antibiotics. Which single feature most favors a bacterial rather than viral etiology?
- Watery serous discharge
- Tender preauricular lymph node
- Recent shared swimming pool exposure
- Persistent thick mucopurulent discharge that reaccumulates after wiping
Correct answer: Persistent thick mucopurulent discharge that reaccumulates after wiping
Persistent thick mucopurulent discharge that reaccumulates after wiping is correct. Continuous purulent discharge that returns within minutes of cleaning the lid is the feature most predictive of bacterial conjunctivitis and supports topical antibiotic therapy. Watery discharge and a tender preauricular node favor viral disease, and pool exposure is a nonspecific clue rather than a discriminating finding.
- A sexually active 24-year-old presents with a one-week history of unilateral mucopurulent conjunctivitis that is not responding to standard topical antibiotics, along with a stringy discharge and a follicular reaction. Which organism should be suspected as a cause of this chronic bacterial conjunctivitis?
- Chlamydia trachomatis
- Staphylococcus epidermidis
- Streptococcus pneumoniae
- Moraxella catarrhalis
Correct answer: Chlamydia trachomatis
Chlamydia trachomatis is the answer. A chronic, follicular, mucopurulent conjunctivitis in a sexually active adult that fails routine topical antibiotics suggests inclusion conjunctivitis from Chlamydia, which requires systemic treatment. Staphylococcus epidermidis, Streptococcus pneumoniae, and Moraxella cause acute self-limited bacterial conjunctivitis that responds to standard topical therapy.
- A 3-year-old with acute otitis media is reassessed. The clinician explains why young children are predisposed to middle ear infections. Which anatomic feature in young children most contributes to this susceptibility?
- A shorter, more horizontal eustachian tube
- A larger mastoid antrum than adults
- An absent tympanic membrane
- A narrower external auditory canal cartilage
Correct answer: A shorter, more horizontal eustachian tube
A shorter, more horizontal eustachian tube is correct. Young children have eustachian tubes that are shorter and more horizontal, impairing middle ear drainage and ventilation and predisposing them to acute otitis media. A larger mastoid antrum, an absent drum, and a narrow canal cartilage are not the recognized anatomic reasons children develop frequent middle ear infections.
- A 2-year-old has had three episodes of acute otitis media in six months. The current episode is mild with minimal symptoms and no severe pain or high fever, and the child is otherwise well. Which 2026 management option is most appropriate for this nonsevere case?
- Immediate tympanostomy tube placement
- Intravenous ceftriaxone for three days
- Watchful waiting with analgesia and a 48 to 72 hour reassessment
- Oral antifungal therapy
Correct answer: Watchful waiting with analgesia and a 48 to 72 hour reassessment
Watchful waiting with analgesia and a 48 to 72 hour reassessment is correct. For an older infant or child with nonsevere acute otitis media, an observation option with pain control and reassessment within a couple of days is appropriate, reserving antibiotics for those who fail to improve. Immediate surgery, intravenous antibiotics, and antifungals are not indicated for a mild, uncomplicated episode.
- A 30-year-old develops a peritonsillar abscess. The clinician wants to confirm the diagnosis and differentiate it from cellulitis when the bedside exam is equivocal. Which imaging study is most useful to identify and localize the abscess collection?
- Plain lateral neck radiograph
- Skull-base bone scan
- Sinus transillumination
- Intraoral or transcervical ultrasound
Correct answer: Intraoral or transcervical ultrasound
Intraoral or transcervical ultrasound is correct. When the diagnosis of a peritonsillar abscess is uncertain, ultrasound can distinguish a drainable fluid collection from peritonsillar cellulitis and guide aspiration, while contrast CT is used for deeper extension. A plain neck radiograph, a bone scan, and sinus transillumination do not reliably identify a peritonsillar pus pocket.
- A 16-year-old develops a peritonsillar abscess. The clinician reviews how this complication usually arises. Which sequence most commonly precedes a peritonsillar abscess?
- Untreated or progressing acute tonsillitis or pharyngitis
- Chronic allergic rhinitis
- A foreign body in the external ear canal
- Repeated episodes of positional vertigo
Correct answer: Untreated or progressing acute tonsillitis or pharyngitis
Untreated or progressing acute tonsillitis or pharyngitis is correct. A peritonsillar abscess typically develops as a suppurative extension of acute tonsillitis or pharyngitis into the potential space between the tonsillar capsule and the pharyngeal muscles. Allergic rhinitis, an ear-canal foreign body, and positional vertigo are unrelated to the pathogenesis of a peritonsillar abscess.
- A 45-year-old presents with rapidly worsening sore throat, drooling, and a muffled voice; the clinician is concerned about adult epiglottitis. Which diagnostic approach is most appropriate to confirm the diagnosis when the airway is stable?
- Blind digital palpation of the epiglottis
- Forced supine positioning for a CT scan without monitoring
- Direct fiberoptic laryngoscopy by experienced personnel in a controlled setting
- Vigorous tongue-blade depression to view the larynx
Correct answer: Direct fiberoptic laryngoscopy by experienced personnel in a controlled setting
Direct fiberoptic laryngoscopy by experienced personnel in a controlled setting is correct. In a stable adult with suspected epiglottitis, careful fiberoptic visualization of a cherry-red swollen epiglottis by skilled clinicians confirms the diagnosis while airway control remains available. Blind palpation, forcing a supine position without monitoring, and aggressive tongue-blade exam can precipitate complete airway obstruction.
- A clinician reviews why the incidence of pediatric epiglottitis has fallen dramatically in recent decades. Which public health measure is most responsible for this decline?
- Routine fluoride supplementation
- Universal newborn hearing screening
- Reduced antibiotic use for otitis media
- Widespread Haemophilus influenzae type b vaccination
Correct answer: Widespread Haemophilus influenzae type b vaccination
Widespread Haemophilus influenzae type b vaccination is correct. Routine Hib immunization has sharply reduced classic pediatric epiglottitis, since this organism was historically the leading cause. Fluoride supplementation, newborn hearing screening, and changes in otitis media antibiotic use have not affected the incidence of epiglottitis.
- A 60-year-old reports that for the past few months it feels like the room spins for several seconds whenever he lies down or rolls over in bed, with no hearing changes. The clinician performs the Dix-Hallpike maneuver and observes characteristic nystagmus. Which finding of the nystagmus most supports benign paroxysmal positional vertigo rather than a central cause?
- Nystagmus that is direction-changing and persists without fatigue
- Vertical down-beating nystagmus present in primary gaze
- Nystagmus with a brief latency that fatigues with repeated testing
- Nystagmus that is unaffected by head position
Correct answer: Nystagmus with a brief latency that fatigues with repeated testing
Nystagmus with a brief latency that fatigues with repeated testing is correct. Peripheral benign paroxysmal positional vertigo produces torsional-upbeating nystagmus that begins after a short latency and fatigues on repetition, distinguishing it from worrisome central patterns. Direction-changing, non-fatiguing, persistent down-beating, or position-independent nystagmus suggests a central rather than benign peripheral cause.
- A patient is diagnosed with benign paroxysmal positional vertigo of the posterior semicircular canal. Which intervention is the most appropriate first-line treatment?
- Long-term daily meclizine
- Surgical labyrinthectomy
- High-dose oral corticosteroids
- Canalith repositioning with the Epley maneuver
Correct answer: Canalith repositioning with the Epley maneuver
Canalith repositioning with the Epley maneuver is correct. The first-line treatment for posterior canal benign paroxysmal positional vertigo is a particle-repositioning procedure such as the Epley maneuver, which moves displaced otoconia out of the canal. Long-term vestibular suppressants are discouraged, surgery is a last resort, and corticosteroids treat vestibular neuritis rather than positional vertigo.
- A 6-year-old presents with bilateral conjunctivitis and concurrent acute otitis media, with watery eye discharge and ear pain. Which organism is classically associated with this conjunctivitis-otitis syndrome?
- Pseudomonas aeruginosa
- Nontypeable Haemophilus influenzae
- Treponema pallidum
- Bordetella pertussis
Correct answer: Nontypeable Haemophilus influenzae
Nontypeable Haemophilus influenzae is the answer. The combination of conjunctivitis and otitis media occurring together is classically caused by nontypeable Haemophilus influenzae, guiding antibiotic choice toward agents with beta-lactamase coverage. Pseudomonas causes ear-canal and contact-lens infections, while Treponema pallidum and Bordetella pertussis are not causes of this conjunctivitis-otitis syndrome.
- A 22-year-old develops a hyperacute, copious purulent conjunctivitis over 12 hours with severe lid swelling and chemosis. Which diagnostic step is most important given the rapid progression and risk of corneal involvement?
- Obtain conjunctival cultures and Gram stain promptly
- Begin only artificial tears
- Reassure and recheck in two weeks
- Apply warm compresses without further evaluation
Correct answer: Obtain conjunctival cultures and Gram stain promptly
Obtaining conjunctival cultures and Gram stain promptly is correct. Hyperacute purulent conjunctivitis raises concern for Neisseria gonorrhoeae, which can penetrate the intact cornea, so urgent Gram stain and culture guide systemic treatment. Reassurance, artificial tears alone, and warm compresses without diagnostics fail to address this sight-threatening infection.
- A 19-year-old contact lens wearer presents with severe eye pain, photophobia, and a corneal infiltrate with an overlying epithelial defect and surrounding stromal haze. Which is the most concerning diagnosis requiring urgent treatment to preserve vision?
- Pinguecula
- Pterygium
- Blepharitis
- Bacterial keratitis
Correct answer: Bacterial keratitis
Bacterial keratitis is the answer. A painful corneal infiltrate with an epithelial defect and stromal haze in a contact lens wearer indicates a corneal infection that can rapidly scar or perforate the cornea, requiring urgent culture and intensive topical antibiotics. A pinguecula and pterygium are benign conjunctival growths, and blepharitis is lid-margin inflammation without a corneal infiltrate.
- A contact lens wearer who swims in lakes presents with severe eye pain out of proportion to findings and a ring-shaped corneal infiltrate that has not responded to standard antibacterial drops. Which organism should be suspected?
- Streptococcus pneumoniae
- Acanthamoeba
- Adenovirus
- Staphylococcus aureus
Correct answer: Acanthamoeba
Acanthamoeba is the answer. Severe pain out of proportion to examination and a ring-shaped stromal infiltrate in a contact lens wearer with freshwater exposure that fails antibacterial therapy suggests Acanthamoeba keratitis. Streptococcus pneumoniae and Staphylococcus aureus cause typical bacterial keratitis, and adenovirus causes conjunctivitis rather than a painful ring infiltrate.
- A patient presents with a painful red eye, photophobia, and tearing. Fluorescein staining of the cornea under cobalt blue light reveals a branching, linear ulcer with terminal bulbs. Which is the most likely diagnosis?
- Bacterial corneal ulcer
- Corneal foreign body
- Herpes simplex keratitis
- Pterygium
Correct answer: Herpes simplex keratitis
Herpes simplex keratitis is the answer. A branching dendritic ulcer with terminal end-bulbs that highlights with fluorescein is the classic sign of herpes simplex virus infection of the cornea, treated with antivirals while avoiding topical steroids alone. A bacterial ulcer produces a round dense infiltrate, a corneal foreign body shows a focal staining defect with a visible object, and a pterygium is a fleshy noninflamed growth.
- A 35-year-old presents with horizontal binocular double vision that resolves when either eye is covered, along with an inability to fully abduct the right eye. Which cranial nerve palsy most likely explains this finding?
- Cranial nerve III (oculomotor)
- Cranial nerve IV (trochlear)
- Cranial nerve VI (abducens)
- Cranial nerve VII (facial)
Correct answer: Cranial nerve VI (abducens)
Cranial nerve VI palsy is the answer. The lateral rectus, which abducts the eye, is innervated by the abducens nerve, so an inability to abduct one eye with horizontal binocular diplopia indicates a sixth nerve palsy. The oculomotor nerve controls most other extraocular movements and the lid, the trochlear nerve controls the superior oblique producing vertical diplopia, and the facial nerve governs facial expression rather than eye movement.
- A 7-year-old is brought in because the left eye turns inward, and a cover-uncover test shows the deviating eye refixates when uncovered. The child has reduced vision in that eye. Which condition must be treated promptly to prevent permanent vision loss from this misalignment?
- Subconjunctival hemorrhage
- Pinguecula
- Strabismus with amblyopia
- Chalazion
Correct answer: Strabismus with amblyopia
Strabismus with amblyopia is the answer. An inward-turning eye revealed by the cover-uncover test in a child with reduced vision indicates strabismus that can lead to amblyopia, requiring prompt correction and patching during the critical period of visual development. A subconjunctival hemorrhage is a painless blood patch, a pinguecula is a benign conjunctival deposit, and a chalazion is a painless eyelid lump.
- A 16-year-old presents with brisk anterior epistaxis that has not stopped after 20 minutes of correct firm pressure. Which is the most appropriate next step in the office?
- Immediate posterior balloon packing
- Topical vasoconstrictor followed by anterior nasal packing or chemical cautery of the bleeding point
- Order an urgent angiogram for embolization
- Discharge with reassurance that it will stop on its own
Correct answer: Topical vasoconstrictor followed by anterior nasal packing or chemical cautery of the bleeding point
Topical vasoconstrictor followed by anterior nasal packing or chemical cautery of the bleeding point is correct. When direct pressure fails to control anterior epistaxis, applying a vasoconstrictor and then cauterizing or packing the identified anterior bleeding source is the next appropriate step. Posterior packing and angiographic embolization are reserved for refractory posterior bleeds, and discharge without intervention is inappropriate for ongoing active bleeding.
- A 70-year-old on warfarin has profuse epistaxis with blood draining into the posterior pharynx and bleeding from both nostrils that is not controlled with anterior packing. Which is the most likely source of this bleeding?
- Kiesselbach plexus
- Anterior ethmoidal vein in the vestibule
- Sphenopalatine artery (posterior source)
- Lacrimal punctum
Correct answer: Sphenopalatine artery (posterior source)
The sphenopalatine artery as a posterior source is correct. Heavy bleeding draining down the posterior pharynx from both nostrils that resists anterior packing suggests a posterior epistaxis from the sphenopalatine artery, which is more common in older anticoagulated patients and may require posterior packing. The Kiesselbach plexus is the anterior source, while the anterior ethmoidal vestibular vessels and the lacrimal punctum do not cause posterior epistaxis.
- A 24-year-old returns from a long flight with severe right ear pain, muffled hearing, and a sensation of pressure that began during descent. Otoscopy shows a retracted tympanic membrane with hemorrhage in the drum. Which is the most likely diagnosis?
- Acute otitis media
- Otitic barotrauma
- Cholesteatoma
- Otosclerosis
Correct answer: Otitic barotrauma
Otitic barotrauma is the answer. Ear pain, muffled hearing, and pressure that develop during the pressure changes of flight, with a retracted and hemorrhagic tympanic membrane, indicate barotrauma from failure to equalize middle ear pressure. Acute otitis media shows a bulging erythematous drum with infection, cholesteatoma is a chronic keratin mass, and otosclerosis causes progressive conductive loss without acute barotrauma.
- A 30-year-old presents with sudden, unilateral, profound sensorineural hearing loss developing over hours with no preceding trauma, and aural fullness without true vertigo. Which is the most appropriate consideration regarding management of this condition?
- It is benign and requires no treatment
- Treat with topical antibiotic ear drops
- Reassure that it always resolves within a year regardless of treatment
- Prompt evaluation and consideration of corticosteroids, as it is a sudden sensorineural hearing loss emergency
Correct answer: Prompt evaluation and consideration of corticosteroids, as it is a sudden sensorineural hearing loss emergency
Prompt evaluation and consideration of corticosteroids is correct. Sudden sensorineural hearing loss developing within hours to days is an otologic emergency in which early corticosteroid therapy improves the chance of recovery, and audiometry and MRI are obtained. It is not benign or self-limited in all cases, and topical antibiotic drops treat external canal infections rather than inner ear loss.
- A 50-year-old reports a left-sided facial droop that involves the forehead and the inability to fully close the left eye, along with hyperacusis and altered taste. There are no other neurologic deficits. Regarding eye care for this peripheral facial palsy, which measure is most important?
- Patch the unaffected eye
- Lubricate and protect the affected eye to prevent exposure keratopathy
- Begin oral antifungal therapy
- Apply a vasoconstrictor to the affected eye
Correct answer: Lubricate and protect the affected eye to prevent exposure keratopathy
Lubricating and protecting the affected eye to prevent exposure keratopathy is correct. When a peripheral facial nerve palsy prevents complete eyelid closure, the exposed cornea is at risk of drying and ulceration, so artificial tears, ointment, and taping or a moisture chamber protect the eye. Patching the unaffected eye, antifungals, and vasoconstrictors do not address the corneal exposure that threatens the affected eye.
- A 30-year-old presents with hoarseness and a breathy voice for three days after cheering loudly at a concert and having a recent cold. Laryngoscopy shows erythematous, edematous vocal cords. Which is the most appropriate initial management of this acute laryngitis?
- Immediate microlaryngeal surgery
- Long-term systemic corticosteroids
- Voice rest, hydration, and humidification
- Daily decongestant nasal spray for a month
Correct answer: Voice rest, hydration, and humidification
Voice rest, hydration, and humidification is correct. Acute laryngitis, usually viral or from vocal overuse, is self-limited and managed conservatively with voice rest, fluids, and humidified air. Surgery is unnecessary for uncomplicated acute laryngitis, prolonged systemic steroids are not appropriate, and long-term decongestant sprays risk rebound congestion without treating the inflamed cords.
- A 38-year-old professional singer has persistent hoarseness for two months. Laryngoscopy reveals small, bilateral, symmetric callous-like lesions at the junction of the anterior and middle thirds of the vocal cords. Which is the most likely diagnosis?
- Laryngeal carcinoma
- Vocal cord nodules
- Epiglottitis
- Reinke edema
Correct answer: Vocal cord nodules
Vocal cord nodules are the answer. Bilateral, symmetric, callous-like lesions at the anterior-middle third junction of the vocal cords in someone with chronic vocal overuse are classic vocal cord nodules, managed with voice therapy. Laryngeal carcinoma usually produces a unilateral mass in a smoker, epiglottitis is an acute supraglottic emergency, and Reinke edema is diffuse polypoid swelling of the cords in smokers.
- A 28-year-old presents with eye redness and irritation and is found to have a fleshy, wing-shaped fibrovascular growth extending from the nasal conjunctiva onto the cornea. He works outdoors in a sunny climate. Which is the most likely diagnosis?
- Hordeolum
- Dacryocystitis
- Cataract
- Pterygium
Correct answer: Pterygium
Pterygium is the answer. A wing-shaped fibrovascular conjunctival growth encroaching onto the cornea in a person with chronic sun and wind exposure is a pterygium, which can be observed unless it threatens vision. A hordeolum is a tender lid-margin stye, dacryocystitis is tear-sac infection at the medial canthus, and a cataract is a clouding of the lens rather than a surface growth.
- A diabetic patient with proliferative diabetic retinopathy is at risk of severe vision loss. Which retinal change defines the proliferative stage and explains the risk of vitreous hemorrhage?
- Neovascularization of the disc or retina
- Hard exudates near the macula
- A few scattered microaneurysms only
- Drusen at the macula
Correct answer: Neovascularization of the disc or retina
Neovascularization of the disc or retina is the answer. The proliferative stage of diabetic retinopathy is defined by growth of fragile new vessels that can bleed into the vitreous and cause tractional detachment, prompting laser or anti-VEGF therapy. Hard exudates and isolated microaneurysms are nonproliferative changes, and drusen are features of macular degeneration rather than diabetic retinopathy.
- A 65-year-old with poorly controlled hypertension undergoes fundoscopy. Which set of findings is most characteristic of hypertensive retinopathy?
- A cherry-red spot with a pale retina
- Arteriovenous nicking, copper wiring, and flame-shaped hemorrhages
- Pearly papule with telangiectasias
- Dendritic ulcer with terminal bulbs
Correct answer: Arteriovenous nicking, copper wiring, and flame-shaped hemorrhages
Arteriovenous nicking, copper wiring, and flame-shaped hemorrhages is correct. Chronic hypertension produces arteriolar narrowing with copper or silver wiring, arteriovenous nicking, flame hemorrhages, and in severe cases papilledema. A cherry-red spot indicates central retinal artery occlusion, a pearly telangiectatic papule is a basal cell carcinoma of the skin, and a dendritic ulcer indicates herpes keratitis.
- A 55-year-old presents with sudden painless decrease in vision in one eye, and fundoscopy shows diffuse retinal hemorrhages in all four quadrants, dilated tortuous veins, and cotton-wool spots, described as a blood-and-thunder appearance. Which is the most likely diagnosis?
- Central retinal artery occlusion
- Open-angle glaucoma
- Central retinal vein occlusion
- Optic neuritis
Correct answer: Central retinal vein occlusion
Central retinal vein occlusion is the answer. Sudden painless monocular vision loss with widespread four-quadrant retinal hemorrhages, dilated tortuous veins, and cotton-wool spots produces the blood-and-thunder fundus of a vein occlusion. A central retinal artery occlusion shows a pale retina with a cherry-red spot, open-angle glaucoma causes gradual peripheral loss, and optic neuritis features pain on eye movement with an afferent pupillary defect.
- A 30-year-old with type 1 diabetes presents in diabetic ketoacidosis and is noted to have black necrotic eschar on the nasal turbinates and palate with facial pain and proptosis. Which invasive infection must be urgently suspected?
- Allergic fungal rhinitis
- Simple viral rhinitis
- Nasal polyposis
- Rhinocerebral mucormycosis
Correct answer: Rhinocerebral mucormycosis
Rhinocerebral mucormycosis is the answer. A black necrotic eschar of the nasal mucosa and palate with facial pain and proptosis in a diabetic or immunocompromised patient indicates angioinvasive mucormycosis, an emergency requiring urgent debridement and antifungal therapy. Allergic fungal rhinitis is noninvasive, viral rhinitis is benign and self-limited, and nasal polyps are pale edematous growths without necrosis.
- A 60-year-old smoker presents with one month of unilateral nasal obstruction, recurrent epistaxis, and a unilateral mass in the nasal cavity. A biopsy is planned. Which is the most appropriate concern driving the evaluation?
- This is certainly benign allergic rhinitis
- A unilateral nasal mass may represent a sinonasal tumor and warrants biopsy
- Warm compresses will resolve the mass
- A trial of antihistamines should be the only management
Correct answer: A unilateral nasal mass may represent a sinonasal tumor and warrants biopsy
A unilateral nasal mass may represent a sinonasal tumor and warrants biopsy is correct. Unilateral nasal obstruction, recurrent epistaxis, and a one-sided mass, especially in a smoker, raise concern for a sinonasal neoplasm and require imaging and biopsy. Allergic rhinitis is bilateral, and warm compresses or antihistamines alone are inappropriate when malignancy is a concern.
- A clinician examines a child with leukocoria, an abnormal white reflex on red-reflex testing, in one eye. Which serious diagnosis must be urgently excluded in a young child with leukocoria?
- Allergic conjunctivitis
- Stye
- Retinoblastoma
- Cerumen impaction
Correct answer: Retinoblastoma
Retinoblastoma is the answer. A white pupillary reflex, or leukocoria, in a young child is a red flag for retinoblastoma, a malignant intraocular tumor that requires urgent ophthalmologic evaluation, though cataract and other causes are also considered. Allergic conjunctivitis, a stye, and cerumen impaction do not produce leukocoria and are not life- or sight-threatening tumors.
- A 45-year-old with poorly controlled HIV reports floaters and progressive painless vision loss; dilated fundoscopy reveals fluffy white retinal infiltrates with associated hemorrhages described as a pizza-pie appearance. Which is the most likely cause of this retinitis?
- Bacterial conjunctivitis
- Episcleritis
- Pinguecula
- Cytomegalovirus retinitis
Correct answer: Cytomegalovirus retinitis
Cytomegalovirus retinitis is the answer. Fluffy yellow-white retinal infiltrates with hemorrhage producing a pizza-pie appearance in a patient with advanced HIV and low CD4 counts indicate cytomegalovirus retinitis, a sight-threatening opportunistic infection. Bacterial conjunctivitis and episcleritis affect the ocular surface, and a pinguecula is a benign conjunctival deposit, none of which cause retinitis.
- A clinician examines a comatose patient and notes one pupil that is fixed and dilated and does not constrict to light, with the eye deviated down and out and a drooping eyelid on the same side. Which cranial nerve is most likely compressed?
- Cranial nerve III (oculomotor)
- Cranial nerve VI (abducens)
- Cranial nerve VII (facial)
- Cranial nerve VIII (vestibulocochlear)
Correct answer: Cranial nerve III (oculomotor)
Cranial nerve III is the answer. A fixed, dilated, unreactive pupil with the eye positioned down and out and ptosis reflects compression of the oculomotor nerve, which carries pupillary parasympathetic fibers and innervates most extraocular muscles and the levator. The abducens nerve controls only lateral gaze, the facial nerve governs facial expression, and the vestibulocochlear nerve mediates hearing and balance rather than pupil and eye position.
- A 35-year-old presents with sudden painful loss of vision after blunt trauma to the eye. Slit-lamp exam shows layered blood in the anterior chamber. Which is the most likely diagnosis and an important associated risk to monitor?
- Cataract, with no acute risk
- Pinguecula, with cosmetic concern only
- Hyphema, with risk of elevated intraocular pressure
- Chalazion, with risk of recurrence
Correct answer: Hyphema, with risk of elevated intraocular pressure
Hyphema with risk of elevated intraocular pressure is correct. Layered blood in the anterior chamber after blunt ocular trauma is a hyphema, which requires monitoring for raised intraocular pressure and rebleeding, often with rest and head elevation. A cataract is a painless chronic lens opacity, a pinguecula is a benign surface deposit, and a chalazion is a painless eyelid lump, none of which involve anterior chamber blood after trauma.
- A 50-year-old presents with one week of bilateral lacy white reticular striations on the buccal mucosa, accompanied by similar pruritic violaceous papules on the wrists. The oral lesions are mildly sensitive but cannot be wiped off. Which is the most likely diagnosis?
- Oral candidiasis
- Aphthous stomatitis
- Leukoplakia
- Oral lichen planus
Correct answer: Oral lichen planus
Oral lichen planus is the answer. Bilateral lacy white reticular striations on the buccal mucosa that cannot be wiped off, accompanied by violaceous pruritic skin papules, are characteristic of lichen planus. Oral candidiasis produces plaques that scrape off, aphthous ulcers are discrete shallow erosions, and leukoplakia is a solid white patch rather than a lacy reticular pattern.
- A 40-year-old reports vertigo and hearing loss, and the clinician explains the difference between a peripheral and a central cause of vertigo. Which feature most strongly suggests a peripheral rather than central origin of vertigo?
- Severe gait ataxia with inability to walk and normal hearing
- Horizontal nystagmus that suppresses with visual fixation and is associated with hearing symptoms
- Direction-changing nystagmus and dysarthria
- Persistent nystagmus with diplopia and focal weakness
Correct answer: Horizontal nystagmus that suppresses with visual fixation and is associated with hearing symptoms
Horizontal nystagmus that suppresses with visual fixation and is associated with hearing symptoms is correct. Peripheral vestibular causes typically produce horizontal-torsional nystagmus that lessens with fixation and often accompany auditory symptoms such as tinnitus or hearing loss. Severe truncal ataxia, direction-changing nystagmus, dysarthria, diplopia, and focal weakness point toward a central cause requiring urgent neuroimaging.
- A 48-year-old man reports a burning retrosternal sensation that occurs after large meals and when lying flat at night, along with an occasional sour taste in his mouth. He has no dysphagia, weight loss, or anemia. Which of the following is the most appropriate initial management?
- A trial of a once-daily proton pump inhibitor with lifestyle modification
- Immediate upper endoscopy to obtain biopsies
- Surgical Nissen fundoplication
- A 14-day course of oral metronidazole
Correct answer: A trial of a once-daily proton pump inhibitor with lifestyle modification
A trial of a once-daily proton pump inhibitor combined with lifestyle changes is the correct first step. In a patient with classic gastroesophageal reflux disease symptoms and no alarm features such as dysphagia, weight loss, or bleeding, empiric acid suppression with weight loss, head-of-bed elevation, and avoiding late meals is standard. Endoscopy is reserved for alarm features or refractory symptoms, fundoplication is for select refractory cases, and antibiotics treat infection, not reflux.
- A 55-year-old man with long-standing gastroesophageal reflux disease undergoes endoscopy that shows salmon-colored mucosa extending into the distal esophagus, with biopsy confirming intestinal metaplasia. This finding most importantly increases his risk for which of the following?
- Achalasia
- Esophageal adenocarcinoma
- Zenker diverticulum
- Diffuse esophageal spasm
Correct answer: Esophageal adenocarcinoma
Esophageal adenocarcinoma is the key risk. The salmon-colored mucosa with intestinal metaplasia describes Barrett esophagus, a complication of chronic reflux in which squamous epithelium is replaced by columnar epithelium. Barrett esophagus is the principal precursor lesion for esophageal adenocarcinoma and warrants endoscopic surveillance. Achalasia, Zenker diverticulum, and esophageal spasm are motility or structural disorders not driven by metaplasia.
- Which of the following pharmacologic agents most effectively suppresses gastric acid secretion by irreversibly blocking the hydrogen-potassium ATPase pump of parietal cells?
- Famotidine
- Sucralfate
- Omeprazole
- Aluminum hydroxide
Correct answer: Omeprazole
Omeprazole is correct. Proton pump inhibitors such as omeprazole irreversibly bind and inhibit the hydrogen-potassium ATPase (the proton pump) on gastric parietal cells, producing profound and durable acid suppression. Famotidine is an H2-receptor antagonist that blocks histamine-mediated secretion less completely, sucralfate forms a protective coating over ulcers, and aluminum hydroxide simply neutralizes existing acid.
- A 60-year-old woman presents with epigastric pain that improves with eating but recurs a few hours later, along with nocturnal awakening from pain. Testing reveals Helicobacter pylori infection and an ulcer in the duodenal bulb. Which regimen is the most appropriate treatment?
- A proton pump inhibitor alone for 8 weeks
- Oral fluconazole for 14 days
- Sucralfate monotherapy with no antibiotics
- A proton pump inhibitor plus clarithromycin and amoxicillin
Correct answer: A proton pump inhibitor plus clarithromycin and amoxicillin
A proton pump inhibitor plus clarithromycin and amoxicillin is correct. Helicobacter pylori-associated peptic ulcer disease requires eradication with combination therapy, classically triple therapy of a PPI and two antibiotics, to heal the ulcer and prevent recurrence. Acid suppression alone, antifungals, or mucosal protectants without antibiotics fail to eradicate the organism and leave the patient at high risk of relapse.
- Besides Helicobacter pylori, which of the following is the most common cause of peptic ulcer disease?
- Chronic nonsteroidal anti-inflammatory drug use
- Excessive dietary fiber intake
- Lactose intolerance
- Chronic proton pump inhibitor use
Correct answer: Chronic nonsteroidal anti-inflammatory drug use
Chronic nonsteroidal anti-inflammatory drug use is the answer. After H. pylori, NSAIDs are the leading cause of peptic ulcers because they inhibit cyclooxygenase and reduce protective mucosal prostaglandins, leaving the mucosa vulnerable to acid injury. Dietary fiber and lactose intolerance do not cause ulcers, and proton pump inhibitors actually protect the mucosa rather than damage it.
- A 50-year-old man with a history of peptic ulcer disease suddenly develops severe, diffuse abdominal pain with a rigid, board-like abdomen. An upright chest radiograph shows free air under the diaphragm. Which complication has most likely occurred?
- Gastric outlet obstruction
- Perforation of the ulcer
- Pernicious anemia
- Reflux esophagitis
Correct answer: Perforation of the ulcer
Perforation is correct. A rigid board-like abdomen with free air under the diaphragm on upright imaging indicates a perforated viscus, a surgical emergency in which the ulcer erodes completely through the wall and releases air and contents into the peritoneum. Gastric outlet obstruction causes vomiting and succussion splash without free air, pernicious anemia is a chronic hematologic complication, and reflux esophagitis does not cause peritonitis.
- A 45-year-old man with heavy alcohol use presents with severe, constant epigastric pain radiating to the back, nausea, and vomiting. Which laboratory finding best supports a diagnosis of acute pancreatitis?
- Elevated serum alkaline phosphatase alone
- Markedly elevated serum ammonia
- Serum lipase elevated more than three times the upper limit of normal
- Positive anti-tissue transglutaminase antibodies
Correct answer: Serum lipase elevated more than three times the upper limit of normal
A serum lipase greater than three times the upper limit of normal is the answer. Lipase is the most specific enzyme for acute pancreatitis and, combined with characteristic pain, satisfies diagnostic criteria. Isolated alkaline phosphatase elevation suggests biliary obstruction, elevated ammonia points to hepatic encephalopathy, and anti-tissue transglutaminase antibodies indicate celiac disease.
- In a patient who does not drink alcohol, which of the following is the most common cause of acute pancreatitis?
- Hypothyroidism
- Iron deficiency
- Chronic constipation
- Gallstones
Correct answer: Gallstones
Gallstones are correct. Together with alcohol, gallstones account for the large majority of acute pancreatitis cases; a stone obstructing the ampulla causes pancreatic ductal hypertension and enzyme activation. Hypothyroidism, iron deficiency, and constipation are not recognized causes of pancreatitis.
- A patient with acute pancreatitis is admitted to the hospital. Which of the following is the cornerstone of early management?
- Aggressive intravenous fluid resuscitation and analgesia
- Immediate exploratory laparotomy
- Oral broad-spectrum antibiotics for all patients
- High-fat enteral feeding within the first hour
Correct answer: Aggressive intravenous fluid resuscitation and analgesia
Aggressive intravenous fluid resuscitation and analgesia is the foundation of early care. Pancreatitis causes large fluid losses into the inflamed retroperitoneum, so early goal-directed fluids and pain control are central. Routine surgery and prophylactic antibiotics are not indicated in uncomplicated cases, and high-fat feeding would worsen pancreatic stimulation early in the course.
- A 24-year-old woman has months of crampy abdominal pain, nonbloody diarrhea, and weight loss. Colonoscopy reveals discontinuous areas of inflammation with skip lesions and cobblestoning involving the terminal ileum. Which diagnosis is most consistent with these findings?
- Ulcerative colitis
- Crohn disease
- Celiac disease
- Irritable bowel syndrome
Correct answer: Crohn disease
Crohn disease is correct. Discontinuous skip lesions, cobblestoning, and terminal ileal involvement are hallmark features of Crohn disease, which can affect any segment of the gastrointestinal tract transmurally. Ulcerative colitis causes continuous inflammation limited to the colon, celiac disease affects the small bowel diffusely without skip lesions, and irritable bowel syndrome produces no structural inflammation.
- Which of the following extraintestinal or transmural complications is most characteristically associated with Crohn disease rather than ulcerative colitis?
- Continuous involvement starting at the rectum
- Lead-pipe appearance of the colon
- Fistula formation between bowel loops or to the skin
- Toxic megacolon as the most common complication
Correct answer: Fistula formation between bowel loops or to the skin
Fistula formation is the answer. Because Crohn disease causes transmural inflammation through the full thickness of the bowel wall, it characteristically forms fistulas, strictures, and abscesses. Continuous rectal involvement and the lead-pipe colon describe ulcerative colitis, and while toxic megacolon can occur in Crohn disease, it is far more classically linked with ulcerative colitis.
- A 28-year-old man reports several weeks of bloody diarrhea with mucus and lower abdominal cramping. Colonoscopy shows continuous inflammation beginning at the rectum and extending proximally without skip areas, limited to the mucosa. Which is the most likely diagnosis?
- Crohn disease
- Diverticulitis
- Acute appendicitis
- Ulcerative colitis
Correct answer: Ulcerative colitis
Ulcerative colitis is correct. Continuous, mucosa-limited inflammation that begins in the rectum and extends proximally without skip lesions is characteristic of ulcerative colitis. Crohn disease shows skip lesions and transmural disease, diverticulitis presents with focal left lower quadrant pain, and appendicitis causes acute right lower quadrant pain rather than chronic bloody diarrhea.
- Patients with long-standing ulcerative colitis require regular surveillance colonoscopy primarily because of an increased risk of which complication?
- Colorectal cancer
- Esophageal varices
- Cholelithiasis
- Peptic ulcer disease
Correct answer: Colorectal cancer
Colorectal cancer is the answer. Chronic colonic inflammation in ulcerative colitis substantially raises the long-term risk of colorectal dysplasia and cancer, which is why surveillance colonoscopy is recommended after years of disease. Varices relate to portal hypertension, gallstones and peptic ulcers are not direct consequences of colonic inflammation.
- A 62-year-old man presents with left lower quadrant abdominal pain, low-grade fever, and a change in bowel habits. Examination shows localized left lower quadrant tenderness. Which imaging study is most appropriate to confirm acute diverticulitis?
- Immediate colonoscopy during the acute episode
- Computed tomography of the abdomen and pelvis with contrast
- Plain abdominal radiograph alone
- Esophagogastroduodenoscopy
Correct answer: Computed tomography of the abdomen and pelvis with contrast
Computed tomography of the abdomen and pelvis with contrast is correct. CT is the test of choice for suspected acute diverticulitis because it confirms the diagnosis and identifies complications such as abscess or perforation. Colonoscopy is avoided acutely due to perforation risk, a plain film lacks sensitivity, and upper endoscopy evaluates the wrong region.
- A patient is diagnosed with uncomplicated acute diverticulitis without abscess, perforation, or systemic toxicity and is able to tolerate oral intake. Which outpatient management approach is most appropriate?
- Emergent sigmoid colectomy
- Long-term daily corticosteroids
- Oral antibiotics with a clear liquid diet and close follow-up
- Immediate colonoscopy to remove diverticula
Correct answer: Oral antibiotics with a clear liquid diet and close follow-up
Oral antibiotics with a clear liquid diet and close follow-up is appropriate for selected uncomplicated cases managed as outpatients. Bowel rest with a clear liquid diet and antibiotics covering gram-negative and anaerobic organisms is standard, with diet advanced as symptoms improve. Surgery is reserved for complicated or recurrent disease, steroids have no role, and diverticula cannot be endoscopically removed.
- A 58-year-old obese woman presents with right upper quadrant pain after a fatty meal, nausea, and inspiratory arrest during deep palpation of the right upper quadrant. Which sign is being elicited and what condition does it suggest?
- A positive McBurney sign suggesting appendicitis
- A positive Rovsing sign suggesting peritonitis
- A positive Cullen sign suggesting pancreatic hemorrhage
- A positive Murphy sign suggesting acute cholecystitis
Correct answer: A positive Murphy sign suggesting acute cholecystitis
A positive Murphy sign suggesting acute cholecystitis is correct. Inspiratory arrest from pain when the inflamed gallbladder descends onto the examiner's hand is the classic Murphy sign of acute cholecystitis, especially in the patient with right upper quadrant pain after a fatty meal. McBurney and Rovsing signs relate to appendicitis, and Cullen sign is periumbilical bruising from retroperitoneal hemorrhage.
- A patient with suspected acute cholecystitis has an equivocal right upper quadrant ultrasound. Which imaging study is most useful to confirm cystic duct obstruction?
- Hepatobiliary iminodiacetic acid (HIDA) scan
- Barium swallow
- Magnetic resonance imaging of the brain
- Colonoscopy
Correct answer: Hepatobiliary iminodiacetic acid (HIDA) scan
A hepatobiliary iminodiacetic acid (HIDA) scan is correct. When ultrasound is inconclusive, a HIDA scan that fails to visualize the gallbladder confirms cystic duct obstruction, the functional hallmark of acute cholecystitis. A barium swallow assesses the esophagus, brain MRI is unrelated, and colonoscopy evaluates the colon.
- A patient is found to have a positive hepatitis B surface antigen, positive hepatitis B e antigen, and a high viral load. Which interpretation of these serologic markers is most accurate?
- Resolved infection with lifelong immunity
- Active hepatitis B infection with high infectivity
- Immunity from prior vaccination
- No evidence of hepatitis B exposure
Correct answer: Active hepatitis B infection with high infectivity
Active hepatitis B infection with high infectivity is correct. The presence of surface antigen indicates active infection, while e antigen positivity with a high viral load reflects active replication and high transmissibility. Resolved infection shows surface antibody plus core antibody, vaccination produces isolated surface antibody, and absence of all markers indicates no exposure.
- A healthcare worker has the following hepatitis B serologies: surface antigen negative, surface antibody positive, and core antibody negative. Which interpretation is correct?
- Acute active infection
- Chronic carrier state
- Immunity due to prior vaccination
- Immunity due to natural prior infection
Correct answer: Immunity due to prior vaccination
Immunity due to prior vaccination is correct. Isolated surface antibody positivity with a negative core antibody indicates a vaccine-induced immune response, because the vaccine contains only surface antigen and does not generate core antibody. Active infection would show surface antigen, a carrier state shows persistent surface antigen, and natural immunity would include a positive core antibody.
- A 30-year-old woman has chronic diarrhea, bloating, weight loss, and an itchy vesicular rash on her elbows. Anti-tissue transglutaminase IgA antibodies are positive. Which dietary intervention is the cornerstone of treatment?
- Permanent lactose elimination only
- Low-fat diet with pancreatic enzyme replacement
- High-fiber diet with stool bulking agents
- Strict lifelong gluten-free diet
Correct answer: Strict lifelong gluten-free diet
A strict lifelong gluten-free diet is correct. Celiac disease is an immune reaction to gluten, and the positive anti-tissue transglutaminase antibodies with the associated dermatitis herpetiformis rash confirm it; eliminating gluten allows the small-bowel villi to heal. Lactose restriction, pancreatic enzymes, and fiber address other conditions and do not treat the underlying gluten sensitivity.
- Celiac disease characteristically causes malabsorption through which pathologic change in the small intestine?
- Villous atrophy of the small-bowel mucosa
- Transmural granulomatous inflammation
- Continuous colonic mucosal ulceration
- Outpouchings of the sigmoid colon wall
Correct answer: Villous atrophy of the small-bowel mucosa
Villous atrophy is the answer. The immune response to gluten flattens and destroys the small-intestinal villi, reducing absorptive surface area and producing malabsorption with deficiencies in iron, folate, and fat-soluble vitamins. Granulomatous transmural inflammation describes Crohn disease, colonic ulceration describes ulcerative colitis, and sigmoid outpouchings describe diverticulosis.
- A 19-year-old man presents with periumbilical pain that migrated to the right lower quadrant, anorexia, low-grade fever, and tenderness at McBurney point. Which is the most likely diagnosis?
- Acute cholecystitis
- Acute appendicitis
- Diverticulitis
- Gastroesophageal reflux disease
Correct answer: Acute appendicitis
Acute appendicitis is correct. Pain that begins periumbilically and migrates to the right lower quadrant with anorexia, fever, and McBurney point tenderness is the classic presentation of appendicitis from luminal obstruction and inflammation. Cholecystitis localizes to the right upper quadrant, diverticulitis to the left lower quadrant, and reflux produces retrosternal burning.
- A 70-year-old man presents with colicky abdominal pain, distension, vomiting, and obstipation. He has a prior abdominal surgery. Plain films show dilated loops of small bowel with air-fluid levels. Which is the most likely cause of his small bowel obstruction?
- Sigmoid diverticulitis
- Acute pancreatitis
- Postoperative adhesions
- Hemorrhoidal disease
Correct answer: Postoperative adhesions
Postoperative adhesions are correct. Adhesions are the most common cause of small bowel obstruction in patients with prior abdominal surgery, and the presentation of colicky pain, distension, vomiting, obstipation, and dilated loops with air-fluid levels is classic. Diverticulitis and pancreatitis do not typically cause mechanical small bowel obstruction, and hemorrhoids are an anorectal condition.
- A 65-year-old man with cirrhosis presents with vomiting bright red blood. Endoscopy reveals bleeding dilated submucosal veins in the distal esophagus. Which underlying mechanism best explains these varices?
- Helicobacter pylori infection
- Gluten sensitivity
- Cystic duct obstruction
- Portal hypertension
Correct answer: Portal hypertension
Portal hypertension is correct. In cirrhosis, increased resistance to portal blood flow raises portal venous pressure and forces blood through collateral channels, dilating submucosal esophageal veins that can rupture and bleed massively. H. pylori causes peptic ulcers, gluten sensitivity causes celiac disease, and cystic duct obstruction causes cholecystitis.
- A 35-year-old woman reports recurrent abdominal pain associated with altered bowel habits that improves after defecation, occurring over more than six months. Extensive workup including labs, colonoscopy, and imaging is unremarkable. Which is the most likely diagnosis?
- Irritable bowel syndrome
- Ulcerative colitis
- Colorectal cancer
- Acute pancreatitis
Correct answer: Irritable bowel syndrome
Irritable bowel syndrome is correct. Chronic recurrent abdominal pain related to defecation and changes in stool frequency or form, with no structural or biochemical abnormality on workup, defines this functional disorder diagnosed by the Rome criteria. Ulcerative colitis, colorectal cancer, and pancreatitis all produce objective abnormalities that would be detected on testing.
- A 68-year-old man reports a recent change in bowel habits, intermittent rectal bleeding, and unintentional weight loss. Colonoscopy reveals an obstructing mass in the descending colon. Which is the most appropriate next diagnostic step to confirm the diagnosis?
- Empiric chemotherapy without tissue confirmation
- Biopsy of the lesion for histologic examination
- A trial of a gluten-free diet
- Treatment with a proton pump inhibitor
Correct answer: Biopsy of the lesion for histologic examination
Biopsy of the lesion for histologic examination is correct. A colonic mass with bleeding, obstruction, and weight loss is highly suspicious for colorectal cancer, and tissue biopsy is required to confirm the diagnosis and guide staging and treatment. Chemotherapy should not begin without histologic confirmation, and dietary or acid-suppression therapy does not address a malignancy.
- At what age does current United States guidance recommend that average-risk adults begin screening for colorectal cancer?
- 21 years
- 65 years
- 45 years
- 75 years
Correct answer: 45 years
Age 45 years is correct. Current guidelines recommend that average-risk adults begin colorectal cancer screening at age 45 with colonoscopy or an approved alternative, reflecting a lowering from the prior age of 50. Age 21 is far too early, and ages 65 and 75 would miss the window when most preventive benefit is gained.
- A 45-year-old man complains of bright red blood coating the stool and on the toilet paper after defecation, with anal itching but no pain. Examination reveals a soft, nontender vascular cushion at the anal verge. Which is the most likely diagnosis?
- Anal fissure
- Colorectal carcinoma
- Acute diverticulitis
- Hemorrhoids
Correct answer: Hemorrhoids
Hemorrhoids are correct. Painless bright red rectal bleeding coating the stool, anal itching, and a soft vascular cushion describe hemorrhoids, dilated venous cushions of the anorectum. An anal fissure causes severe pain with defecation, colorectal carcinoma typically causes weight loss and habit change, and diverticulitis causes left lower quadrant pain rather than anal bleeding.
- A 30-year-old woman reports severe, sharp anal pain during and after bowel movements with a small streak of bright red blood on the tissue, often following constipation. Which is the most likely diagnosis?
- Anal fissure
- Internal hemorrhoid
- Perirectal abscess
- Rectal prolapse
Correct answer: Anal fissure
Anal fissure is correct. A linear tear in the anoderm, usually from passage of hard stool, causes characteristic severe pain during and after defecation with a small amount of bright red blood. Internal hemorrhoids are typically painless, a perirectal abscess produces a tender fluctuant mass with fever, and rectal prolapse presents as protruding tissue rather than a painful tear.
- A patient hospitalized and treated with broad-spectrum antibiotics develops profuse watery diarrhea, abdominal cramping, and fever. Stool testing is positive for Clostridioides difficile toxin. Which is the most appropriate first-line treatment?
- Intravenous ceftriaxone
- Oral vancomycin or oral fidaxomicin
- Loperamide alone
- A gluten-free diet
Correct answer: Oral vancomycin or oral fidaxomicin
Oral vancomycin or oral fidaxomicin is correct. Antibiotic-associated Clostridioides difficile colitis is treated with oral vancomycin or fidaxomicin, which act directly in the colonic lumen. Adding more broad-spectrum antibiotics like ceftriaxone worsens the dysbiosis, antimotility agents alone can precipitate toxic megacolon, and diet changes do not eradicate the organism.
- A 60-year-old man with peripheral vascular disease develops sudden left lower quadrant pain followed by bloody diarrhea. Colonoscopy shows segmental mucosal inflammation at the splenic flexure, a known watershed area. Which is the most likely diagnosis?
- Ulcerative colitis
- Celiac disease
- Ischemic colitis
- Hemorrhoids
Correct answer: Ischemic colitis
Ischemic colitis is correct. Sudden abdominal pain and bloody diarrhea with segmental involvement at watershed areas such as the splenic flexure in a patient with vascular disease reflects transient colonic hypoperfusion. Ulcerative colitis causes continuous rectal disease, celiac disease affects the small bowel, and hemorrhoids do not cause segmental colonic ischemia.
- A 40-year-old man reports progressive difficulty swallowing both solids and liquids, with occasional regurgitation of undigested food. A barium swallow shows a dilated esophagus tapering to a bird-beak appearance at the lower esophageal sphincter. Which is the most likely diagnosis?
- Gastroesophageal reflux disease
- Pyloric stenosis
- Acute pancreatitis
- Achalasia
Correct answer: Achalasia
Achalasia is correct. Dysphagia to both solids and liquids with regurgitation and a bird-beak narrowing of the lower esophageal sphincter on barium swallow reflects failure of the sphincter to relax due to loss of esophageal myenteric neurons. Reflux causes heartburn rather than a bird-beak, pyloric stenosis affects the gastric outlet, and pancreatitis is not an esophageal disorder.
- A 3-week-old male infant presents with progressive nonbilious projectile vomiting after feeds and an olive-shaped mass palpable in the epigastrium. Which is the most likely diagnosis?
- Hypertrophic pyloric stenosis
- Gastroesophageal reflux
- Intussusception
- Acute appendicitis
Correct answer: Hypertrophic pyloric stenosis
Hypertrophic pyloric stenosis is correct. Nonbilious projectile vomiting in a firstborn infant around 3 to 6 weeks of age with a palpable olive-shaped epigastric mass is classic for pyloric stenosis, in which hypertrophied pyloric muscle obstructs gastric outflow. Reflux causes nonprojectile spit-ups, intussusception causes currant-jelly stools, and appendicitis is rare in neonates.
- A 9-month-old infant presents with episodes of intermittent severe crying with drawing up of the legs, vomiting, and stools that resemble currant jelly. Which is the most likely diagnosis?
- Hypertrophic pyloric stenosis
- Intussusception
- Celiac disease
- Hirschsprung disease
Correct answer: Intussusception
Intussusception is correct. Intermittent colicky pain with leg drawing, vomiting, and currant-jelly stools in an infant describes intussusception, where one segment of bowel telescopes into another causing ischemia. Pyloric stenosis causes projectile nonbilious vomiting, celiac disease causes chronic diarrhea, and Hirschsprung disease presents with failure to pass meconium and chronic constipation.
- A 55-year-old man with a long history of alcohol use develops sudden severe chest and epigastric pain after an episode of forceful vomiting, followed by subcutaneous emphysema in the neck. Imaging suggests a full-thickness esophageal rupture. Which condition does this represent?
- Mallory-Weiss tear
- Zenker diverticulum
- Boerhaave syndrome
- Barrett esophagus
Correct answer: Boerhaave syndrome
Boerhaave syndrome is correct. A full-thickness esophageal rupture after forceful vomiting, with chest pain and subcutaneous emphysema, defines Boerhaave syndrome, a surgical emergency. A Mallory-Weiss tear is only a mucosal laceration causing bleeding without perforation, a Zenker diverticulum is an outpouching causing dysphagia, and Barrett esophagus is metaplasia from chronic reflux.
- A 40-year-old man presents with hematemesis after repeated forceful vomiting and retching during an episode of binge drinking. Endoscopy shows a longitudinal mucosal tear at the gastroesophageal junction without perforation. Which is the most likely diagnosis?
- Boerhaave syndrome
- Esophageal varices
- Peptic ulcer perforation
- Mallory-Weiss tear
Correct answer: Mallory-Weiss tear
Mallory-Weiss tear is correct. A longitudinal mucosal laceration at the gastroesophageal junction following retching, causing upper gastrointestinal bleeding without full-thickness rupture, defines a Mallory-Weiss tear. Boerhaave syndrome is a full-thickness rupture, varices are dilated submucosal veins from portal hypertension, and a perforated ulcer would show free air rather than a mucosal tear.
- A 50-year-old woman with obesity and type 2 diabetes is found to have mildly elevated liver enzymes and a fatty liver on ultrasound, with no history of significant alcohol use. Which is the most appropriate initial management?
- Weight loss and control of metabolic risk factors
- Long-term oral corticosteroids
- Immediate liver transplantation
- Lifelong antiviral therapy
Correct answer: Weight loss and control of metabolic risk factors
Weight loss and control of metabolic risk factors is correct. Nonalcoholic fatty liver disease in a patient with obesity and diabetes is managed primarily by gradual weight loss, exercise, and optimizing glucose and lipid control, which can reverse hepatic steatosis. Corticosteroids and antivirals do not treat this metabolic condition, and transplantation is reserved for end-stage liver failure.
- An unvaccinated traveler returns from a developing country with fever, malaise, anorexia, jaundice, and right upper quadrant discomfort after consuming contaminated food and water. Serology confirms acute hepatitis A. Which statement about this infection is most accurate?
- It commonly progresses to cirrhosis if untreated
- It is self-limited and does not cause chronic infection
- It is transmitted primarily through sexual contact
- It requires lifelong antiviral therapy
Correct answer: It is self-limited and does not cause chronic infection
It is self-limited and does not cause chronic infection is correct. Hepatitis A is spread by the fecal-oral route through contaminated food or water and causes an acute, self-limited illness that does not become chronic. It does not progress to cirrhosis from a single infection, is not primarily sexually transmitted, and is managed supportively rather than with lifelong antivirals.
- A patient is found to be positive for hepatitis C antibody, and a follow-up hepatitis C RNA test confirms active viremia. Compared with hepatitis A, hepatitis C is most notable for which feature?
- Reliable resolution without any chronic phase
- Transmission primarily through contaminated food
- A high rate of progression to chronic infection
- Prevention by a widely available vaccine
Correct answer: A high rate of progression to chronic infection
A high rate of progression to chronic infection is correct. Hepatitis C frequently becomes chronic and is a leading cause of cirrhosis and hepatocellular carcinoma, in contrast to the self-limited course of hepatitis A. It is spread mainly through blood exposure rather than food, and unlike hepatitis A and B there is currently no vaccine.
- A 58-year-old man with chronic alcohol use presents with abdominal distension, jaundice, spider angiomata, and palmar erythema. Examination reveals shifting dullness consistent with ascites. Which underlying process best explains the ascites?
- Acute pancreatic enzyme leakage
- Bacterial overgrowth of the small bowel
- Gluten-induced villous atrophy
- Portal hypertension with reduced hepatic albumin synthesis
Correct answer: Portal hypertension with reduced hepatic albumin synthesis
Portal hypertension with reduced hepatic albumin synthesis is correct. Cirrhosis produces ascites through elevated portal pressure and decreased synthesis of albumin, lowering oncotic pressure and allowing fluid to accumulate in the peritoneum; spider angiomata and palmar erythema reflect the same chronic liver dysfunction. The other options describe pancreatitis, bacterial overgrowth, and celiac disease, none of which explain this picture.
- A patient with cirrhosis and ascites develops fever, abdominal pain, and worsening confusion. Paracentesis shows an ascitic fluid neutrophil count above 250 cells per microliter. Which diagnosis and treatment are most appropriate?
- Spontaneous bacterial peritonitis treated with a third-generation cephalosporin
- Acute cholecystitis treated with cholecystectomy
- Celiac disease treated with a gluten-free diet
- Diverticulitis treated with bowel resection
Correct answer: Spontaneous bacterial peritonitis treated with a third-generation cephalosporin
Spontaneous bacterial peritonitis treated with a third-generation cephalosporin is correct. An ascitic fluid neutrophil count above 250 cells per microliter in a cirrhotic patient indicates spontaneous bacterial peritonitis, treated empirically with a third-generation cephalosporin such as cefotaxime. The other diagnoses do not produce neutrocytic ascitic fluid in this setting.
- A 30-year-old woman reports bloating, cramping, and watery diarrhea that occur specifically after consuming dairy products and resolve when she avoids them. A hydrogen breath test is positive after a lactose load. Which is the most likely diagnosis?
- Celiac disease
- Lactose intolerance
- Crohn disease
- Acute pancreatitis
Correct answer: Lactose intolerance
Lactose intolerance is correct. Symptoms triggered by dairy and a positive lactose hydrogen breath test indicate deficiency of intestinal lactase, leaving undigested lactose to ferment and draw water into the bowel. Celiac disease is triggered by gluten, Crohn disease produces structural inflammation, and pancreatitis presents with severe epigastric pain.
- A 60-year-old man presents with a bulge in the groin that protrudes with coughing and reduces when he lies down, located above the inguinal ligament. The bulge is reducible and nontender. Which is the most likely diagnosis?
- Femoral hernia incarceration
- Acute appendicitis
- Inguinal hernia
- Testicular torsion
Correct answer: Inguinal hernia
Inguinal hernia is correct. A reducible groin bulge above the inguinal ligament that appears with increased intra-abdominal pressure and reduces when supine describes an inguinal hernia. A femoral hernia lies below the ligament and the scenario describes a reducible nontender mass rather than incarceration, while appendicitis and testicular torsion present with acute pain rather than a reducible bulge.
- A patient with a known abdominal wall hernia presents with a painful, firm, nonreducible bulge accompanied by nausea, vomiting, and signs of bowel obstruction. Which complication has most likely occurred?
- Spontaneous resolution
- Reflux esophagitis
- Celiac crisis
- Strangulation of the hernia
Correct answer: Strangulation of the hernia
Strangulation of the hernia is correct. A previously reducible hernia that becomes painful, firm, and irreducible with obstructive symptoms suggests incarceration progressing to strangulation, in which the trapped bowel's blood supply is compromised, a surgical emergency. The remaining options do not explain an acutely irreducible, tender hernia with obstruction.
- A patient with chronic alcohol use disorder presents with confusion, ophthalmoplegia, and ataxia. Which vitamin deficiency is the most likely cause, and what is the appropriate immediate treatment?
- Thiamine deficiency treated with intravenous thiamine before glucose
- Vitamin C deficiency treated with oral ascorbic acid
- Vitamin D deficiency treated with cholecalciferol
- Folate deficiency treated with oral folate
Correct answer: Thiamine deficiency treated with intravenous thiamine before glucose
Thiamine deficiency treated with intravenous thiamine before glucose is correct. The triad of confusion, ophthalmoplegia, and ataxia is Wernicke encephalopathy from thiamine deficiency, and thiamine must be given before glucose to avoid precipitating or worsening the syndrome. Vitamin C, D, and folate deficiencies produce different clinical pictures and do not cause this triad.
- A patient with severe fat malabsorption from chronic pancreatic insufficiency is at greatest risk for deficiency of which group of vitamins?
- Vitamin C and the B-complex water-soluble vitamins
- Fat-soluble vitamins A, D, E, and K
- Vitamin B12 exclusively
- Niacin and thiamine only
Correct answer: Fat-soluble vitamins A, D, E, and K
Fat-soluble vitamins A, D, E, and K is correct. Because dietary fat is required to absorb the fat-soluble vitamins, conditions causing fat malabsorption such as pancreatic insufficiency place patients at greatest risk for deficiencies of vitamins A, D, E, and K. The water-soluble vitamins are absorbed independently of fat and are less affected by steatorrhea.
- A sailor on a prolonged voyage with a diet devoid of fresh fruits and vegetables develops bleeding, swollen gums, perifollicular hemorrhages, and poor wound healing. Which vitamin deficiency is most likely?
- Vitamin K deficiency
- Thiamine deficiency
- Vitamin C deficiency
- Vitamin A deficiency
Correct answer: Vitamin C deficiency
Vitamin C deficiency is correct. Scurvy from inadequate vitamin C impairs collagen synthesis, producing swollen bleeding gums, perifollicular hemorrhages, and poor wound healing, classically in those lacking fresh produce. Vitamin K deficiency causes coagulopathy, thiamine deficiency causes neurologic disease, and vitamin A deficiency causes night blindness.
- A patient with Crohn disease who has had ileal resection develops a macrocytic anemia and peripheral neuropathy. Deficiency of which nutrient best explains both findings?
- Iron
- Vitamin C
- Calcium
- Vitamin B12
Correct answer: Vitamin B12
Vitamin B12 is correct. The terminal ileum absorbs vitamin B12, so ileal disease or resection in Crohn disease leads to B12 deficiency, which causes macrocytic anemia and neurologic symptoms such as peripheral neuropathy. Iron deficiency causes microcytic anemia without neuropathy, vitamin C deficiency causes scurvy, and calcium deficiency does not produce macrocytosis.
- A 22-year-old man presents with right lower quadrant pain, and during examination, palpation of the left lower quadrant elicits pain in the right lower quadrant. Which finding does this represent and what does it suggest?
- A positive Rovsing sign suggesting appendicitis
- A positive Murphy sign suggesting cholecystitis
- A positive psoas sign suggesting diverticulitis
- A positive Cullen sign suggesting pancreatitis
Correct answer: A positive Rovsing sign suggesting appendicitis
A positive Rovsing sign suggesting appendicitis is correct. Referred right lower quadrant pain when the left lower quadrant is palpated is the Rovsing sign, which supports peritoneal irritation from appendicitis. The Murphy sign relates to the gallbladder, the psoas sign involves hip extension, and the Cullen sign is periumbilical ecchymosis.
- A 65-year-old man with poorly controlled gastroesophageal reflux develops progressive dysphagia to solids and significant weight loss. Endoscopy and biopsy reveal a malignancy of the distal esophagus arising from glandular tissue. Which type of esophageal cancer and predisposing condition are most consistent?
- Squamous cell carcinoma associated with smoking and alcohol
- Adenocarcinoma associated with Barrett esophagus
- Lymphoma associated with celiac disease
- Carcinoid associated with pernicious anemia
Correct answer: Adenocarcinoma associated with Barrett esophagus
Adenocarcinoma associated with Barrett esophagus is correct. A distal esophageal malignancy of glandular origin in a patient with chronic reflux reflects adenocarcinoma arising from Barrett metaplasia, the dominant esophageal cancer in this setting. Squamous cell carcinoma is more proximal and linked to smoking and alcohol, while lymphoma and carcinoid are not the typical reflux-associated esophageal cancers.
- A 24-year-old woman with celiac disease who has poor dietary adherence is most likely to develop which nutritional deficiency causing a microcytic anemia?
- Vitamin B12 deficiency
- Vitamin K deficiency
- Iron deficiency
- Zinc deficiency
Correct answer: Iron deficiency
Iron deficiency is correct. The duodenum, the primary site of iron absorption, is most affected by the villous atrophy of celiac disease, so iron deficiency producing a microcytic anemia is the classic finding. Vitamin B12 deficiency causes macrocytic anemia and is absorbed in the ileum, vitamin K deficiency causes coagulopathy, and zinc deficiency does not produce a microcytic anemia.
- A 50-year-old man undergoing nutritional support after prolonged starvation suddenly develops low phosphate, low potassium, and low magnesium with fluid retention shortly after aggressive feeding is started. Which complication is occurring?
- Dumping syndrome
- Acute pancreatitis
- Celiac crisis
- Refeeding syndrome
Correct answer: Refeeding syndrome
Refeeding syndrome is correct. Aggressive reintroduction of nutrition after starvation triggers an insulin surge that drives phosphate, potassium, and magnesium into cells, producing the characteristic electrolyte shifts and fluid retention of refeeding syndrome. Dumping syndrome follows gastric surgery, while pancreatitis and celiac crisis do not produce this specific electrolyte pattern after refeeding.
- A 26-year-old woman presents with chronic intermittent diarrhea, abdominal pain, and weight loss. Laboratory testing reveals iron deficiency anemia and a low vitamin D level, and anti-tissue transglutaminase IgA is markedly elevated. Which confirmatory test should be performed next?
- Small-bowel biopsy showing villous atrophy
- Stool culture for enteric pathogens
- Abdominal ultrasound of the gallbladder
- Colonoscopy with random colonic biopsies
Correct answer: Small-bowel biopsy showing villous atrophy
Small-bowel biopsy showing villous atrophy is correct. When serologic testing such as anti-tissue transglutaminase IgA suggests celiac disease, duodenal biopsy demonstrating villous atrophy confirms the diagnosis while the patient is still consuming gluten. Stool culture evaluates infection, gallbladder ultrasound assesses biliary disease, and colonic biopsy targets the colon rather than the small bowel affected in celiac disease.
- A patient diagnosed with acute pancreatitis has the following on admission: age over 55, white blood cell count above 16,000, glucose above 200, and elevated lactate dehydrogenase. These parameters are used in which prognostic assessment, and what do multiple positive criteria indicate?
- The CURB-65 score, indicating pneumonia severity
- Ranson criteria, indicating increased risk of severe pancreatitis and mortality
- The Wells score, indicating pulmonary embolism probability
- The CHA2DS2-VASc score, indicating stroke risk
Correct answer: Ranson criteria, indicating increased risk of severe pancreatitis and mortality
Ranson criteria indicating increased risk of severe pancreatitis and mortality is correct. Age, leukocytosis, hyperglycemia, and elevated lactate dehydrogenase are components of the Ranson criteria used at admission to estimate pancreatitis severity and prognosis, with more positive criteria predicting worse outcomes. CURB-65 grades pneumonia, the Wells score estimates pulmonary embolism, and CHA2DS2-VASc estimates stroke risk in atrial fibrillation.
- A 70-year-old woman presents with painless jaundice, weight loss, and a nontender palpable gallbladder. Imaging shows a mass in the head of the pancreas obstructing the common bile duct. Which classic eponymous sign is described by the palpable nontender gallbladder in this setting?
- Murphy sign
- McBurney sign
- Courvoisier sign
- Grey Turner sign
Correct answer: Courvoisier sign
Courvoisier sign is correct. A palpable, nontender, distended gallbladder in a patient with painless jaundice suggests malignant obstruction of the common bile duct, classically from pancreatic head cancer, and is termed the Courvoisier sign. The Murphy sign indicates cholecystitis, the McBurney sign indicates appendicitis, and the Grey Turner sign is flank ecchymosis from retroperitoneal hemorrhage.
- A 35-year-old man with HIV and a CD4 count below 100 presents with painful swallowing. Endoscopy reveals white plaques coating the esophageal mucosa that scrape off to reveal an erythematous base. Which is the most likely cause of his esophagitis?
- Herpes simplex virus
- Acid reflux
- Eosinophilic infiltration
- Candida species
Correct answer: Candida species
Candida species is correct. White, adherent plaques causing painful swallowing in a severely immunocompromised patient with a low CD4 count are characteristic of Candida esophagitis, the most common cause of esophagitis in advanced HIV. Herpes esophagitis typically causes discrete ulcers, acid reflux causes erosive changes without plaques, and eosinophilic esophagitis produces rings and furrows rather than removable white plaques.
- A 45-year-old man presents with sudden severe right flank pain that radiates to the groin, waxing and waning in intensity, and he cannot find a comfortable position. Urinalysis shows microscopic hematuria. Which imaging study is the preferred initial test to confirm the suspected diagnosis?
- Noncontrast helical computed tomography of the abdomen and pelvis
- Plain abdominal radiograph alone
- Voiding cystourethrogram
- Retrograde urethrogram
Correct answer: Noncontrast helical computed tomography of the abdomen and pelvis
Noncontrast helical computed tomography of the abdomen and pelvis is the answer. In suspected nephrolithiasis, this study is the most sensitive and specific test for detecting stones of essentially any composition and locating them along the ureter. A plain film misses radiolucent stones and lacks the sensitivity of computed tomography.
- A 38-year-old woman has a 4 mm distal ureteral stone with colicky flank pain but normal renal function, no fever, and well-controlled pain. Which management approach is most appropriate as the initial strategy?
- Immediate open surgical removal
- Emergent placement of a nephrostomy tube
- Hydration, analgesia, and medical expulsive therapy with an alpha-blocker
- Long-term prophylactic antibiotics
Correct answer: Hydration, analgesia, and medical expulsive therapy with an alpha-blocker
Hydration, analgesia, and medical expulsive therapy with an alpha-blocker is the answer. Small distal ureteral stones under about 5 mm usually pass spontaneously, and an alpha-blocker such as tamsulosin relaxes ureteral smooth muscle to facilitate passage. Invasive intervention is reserved for larger stones, obstruction with infection, or intractable symptoms.
- A patient passes a kidney stone and chemical analysis identifies it as calcium oxalate, the most common stone type. Which dietary recommendation is appropriate to reduce recurrence?
- Severely restrict dietary calcium intake
- Increase fluid intake and reduce sodium and oxalate-rich foods
- Increase animal protein and salt intake
- Restrict total fluid intake to concentrate the urine
Correct answer: Increase fluid intake and reduce sodium and oxalate-rich foods
Increasing fluid intake and reducing sodium and oxalate-rich foods is the answer. High urine volume dilutes lithogenic solutes, while limiting sodium decreases urinary calcium excretion and limiting oxalate reduces stone formation. Severely restricting dietary calcium is counterproductive because it can paradoxically raise urinary oxalate absorption.
- A 16-year-old boy awakens with sudden severe left testicular pain, nausea, and vomiting. The affected testis is high-riding with a horizontal lie, and the cremasteric reflex is absent on that side. Which is the most appropriate immediate action?
- Schedule an outpatient ultrasound in one week
- Obtain emergent urologic consultation for surgical exploration
- Prescribe oral antibiotics and reassess in 48 hours
- Apply scrotal elevation and observe overnight
Correct answer: Obtain emergent urologic consultation for surgical exploration
Obtaining emergent urologic consultation for surgical exploration is the answer. Testicular torsion is a surgical emergency, and the testis must be detorsed and fixed within roughly six hours to maximize salvage. An absent cremasteric reflex with a high-riding testis strongly supports torsion, and surgery should not be delayed for prolonged imaging.
- A clinician evaluates an adolescent with acute scrotal pain and is deciding between testicular torsion and epididymitis. Which physical examination finding most favors torsion over epididymitis?
- Relief of pain with elevation of the scrotum
- Gradual onset of pain over several days
- Absence of the cremasteric reflex on the affected side
- Dysuria with urethral discharge
Correct answer: Absence of the cremasteric reflex on the affected side
Absence of the cremasteric reflex on the affected side is the answer. Loss of the cremasteric reflex is a sensitive sign of testicular torsion, whereas relief of pain on scrotal elevation, a positive Prehn sign, points toward epididymitis. Torsion characteristically has abrupt onset without urinary symptoms.
- A 24-year-old sexually active man has gradual onset of unilateral scrotal pain and swelling over two days, dysuria, and tenderness localized to the posterior aspect of the testis. Lifting the scrotum relieves his pain. Which is the most likely diagnosis?
- Epididymitis
- Testicular torsion
- Varicocele
- Inguinal hernia
Correct answer: Epididymitis
Epididymitis is the answer. Gradual onset of posterior scrotal tenderness with dysuria and a positive Prehn sign, where elevation eases the pain, is characteristic of epididymitis. The gradual course and urinary symptoms distinguish it from the abrupt, severe presentation of torsion.
- A 22-year-old sexually active man is diagnosed with acute epididymitis. Which pair of organisms is the most likely cause in this age group, guiding empiric antibiotic selection?
- Staphylococcus aureus and Streptococcus pyogenes
- Escherichia coli and Pseudomonas aeruginosa
- Candida albicans and Trichomonas vaginalis
- Neisseria gonorrhoeae and Chlamydia trachomatis
Correct answer: Neisseria gonorrhoeae and Chlamydia trachomatis
Neisseria gonorrhoeae and Chlamydia trachomatis is the answer. In sexually active men younger than 35, epididymitis is most often caused by these sexually transmitted organisms, so empiric therapy targets both. In older men or those with urinary tract abnormalities, enteric gram-negative bacteria become more likely.
- A 68-year-old man reports a weak urinary stream, hesitancy, nocturia, and a sensation of incomplete emptying. Digital rectal examination reveals a smoothly enlarged, nontender prostate. Which class of medication provides the most rapid symptom relief by relaxing prostatic smooth muscle?
- Alpha-1 adrenergic antagonists
- Oral antibiotics
- Loop diuretics
- 5-alpha-reductase inhibitors
Correct answer: Alpha-1 adrenergic antagonists
Alpha-1 adrenergic antagonists are the answer. Agents such as tamsulosin relax smooth muscle in the prostate and bladder neck, producing rapid improvement in lower urinary tract symptoms of benign prostatic hyperplasia. A 5-alpha-reductase inhibitor shrinks the gland but takes months to act.
- A 70-year-old man with a markedly enlarged prostate on examination is started on finasteride for benign prostatic hyperplasia. Which mechanism explains how this drug reduces prostate volume over time?
- It blocks alpha receptors at the bladder neck
- It inhibits conversion of testosterone to dihydrotestosterone
- It directly antagonizes estrogen receptors
- It increases detrusor muscle contractility
Correct answer: It inhibits conversion of testosterone to dihydrotestosterone
Inhibiting conversion of testosterone to dihydrotestosterone is the answer. 5-alpha-reductase inhibitors like finasteride lower dihydrotestosterone, the androgen driving prostatic growth, gradually shrinking the gland over several months. This contrasts with alpha-blockers, which relieve symptoms quickly by relaxing smooth muscle rather than reducing size.
- A man with benign prostatic hyperplasia taking a 5-alpha-reductase inhibitor has his prostate-specific antigen checked during monitoring. How does this medication typically affect the prostate-specific antigen value?
- It eliminates the need to ever check prostate-specific antigen
- It causes a transient marked elevation
- It has no effect on prostate-specific antigen levels
- It lowers prostate-specific antigen by roughly half
Correct answer: It lowers prostate-specific antigen by roughly half
Lowering prostate-specific antigen by roughly half is the answer. 5-alpha-reductase inhibitors reduce measured prostate-specific antigen by approximately 50 percent after several months, so clinicians must double the value when interpreting cancer screening results. Failing to account for this can mask a rising level concerning for malignancy.
- A 25-year-old woman has dysuria, urinary frequency, and suprapubic discomfort without fever or flank pain. Urinalysis shows positive leukocyte esterase and nitrites. Which is the most appropriate initial management for this uncomplicated infection?
- Hospital admission for intravenous antibiotics
- A short course of an oral antibiotic such as nitrofurantoin
- Immediate cystoscopy
- No treatment and observation
Correct answer: A short course of an oral antibiotic such as nitrofurantoin
A short course of an oral antibiotic such as nitrofurantoin is the answer. Uncomplicated cystitis in a healthy nonpregnant woman is treated empirically with a brief oral regimen, and positive nitrites suggest a gram-negative organism. Cystoscopy and intravenous therapy are unnecessary for straightforward lower tract infection.
- A urinalysis reports positive nitrites in a patient with dysuria. Why does a positive nitrite test specifically support a bacterial urinary tract infection?
- Nitrites reflect the presence of red blood cells in the urine
- Certain bacteria reduce urinary nitrates to nitrites
- Nitrites indicate glucose spilling into the urine
- Nitrites are produced only by the kidney during inflammation
Correct answer: Certain bacteria reduce urinary nitrates to nitrites
Certain bacteria reduce urinary nitrates to nitrites is the answer. Gram-negative organisms such as Escherichia coli convert dietary nitrate to nitrite, so a positive nitrite test is fairly specific for these bacteria. Because not all uropathogens reduce nitrate, a negative test does not exclude infection.
- A 28-year-old woman who is 20 weeks pregnant has a routine urine culture growing 100,000 colony-forming units per milliliter of Escherichia coli, but she has no symptoms. Which management is most appropriate?
- No treatment unless symptoms develop
- Treat with an antibiotic safe in pregnancy
- Repeat the culture in the third trimester only
- Start chronic suppressive therapy for the remainder of pregnancy
Correct answer: Treat with an antibiotic safe in pregnancy
Treating with an antibiotic safe in pregnancy is the answer. Asymptomatic bacteriuria is treated in pregnant patients because untreated infection raises the risk of pyelonephritis and preterm birth, unlike in nonpregnant adults where it is generally not treated. Appropriate agents are selected based on safety in pregnancy and culture sensitivities.
- A 30-year-old woman has dysuria, fever, chills, and right costovertebral angle tenderness, with pyuria and white blood cell casts on urinalysis. Which diagnosis does this presentation most strongly indicate?
- Acute cystitis
- Pyelonephritis
- Urethritis
- Interstitial cystitis
Correct answer: Pyelonephritis
Pyelonephritis is the answer. Fever, flank or costovertebral angle tenderness, and white blood cell casts indicate upper urinary tract infection involving the kidney rather than the bladder alone. White blood cell casts in particular point to a renal parenchymal source.
- A 66-year-old man undergoing prostate cancer screening has an elevated prostate-specific antigen and a hard, irregular nodule on the right lobe of the prostate during digital rectal examination. Which is the most appropriate next step to establish a tissue diagnosis?
- Begin androgen deprivation therapy immediately
- Start an alpha-blocker and recheck in one year
- Treat empirically with antibiotics
- Transrectal ultrasound-guided prostate biopsy
Correct answer: Transrectal ultrasound-guided prostate biopsy
Transrectal ultrasound-guided prostate biopsy is the answer. A suspicious nodule with an elevated prostate-specific antigen requires histologic confirmation before treatment decisions, and biopsy provides tissue for diagnosis and Gleason grading. Therapy is not initiated without a confirmed diagnosis.
- A man is diagnosed with prostate adenocarcinoma after biopsy. Which grading system is used by the pathologist to describe the histologic aggressiveness of the tumor and help guide prognosis?
- Gleason score
- Breslow depth
- Bethesda system
- Ranson criteria
Correct answer: Gleason score
The Gleason score is the answer. Prostate cancer aggressiveness is assessed by summing the two most common architectural patterns to generate a Gleason score, which strongly influences prognosis and treatment. Breslow depth applies to melanoma, not prostate cancer.
- An 80-year-old man with low-grade, low-volume prostate cancer and significant comorbidities is counseled on options. Which strategy emphasizes monitoring the tumor with periodic prostate-specific antigen, examinations, and repeat biopsies, deferring treatment unless progression occurs?
- Radical prostatectomy
- Active surveillance
- External beam radiation
- Immediate chemotherapy
Correct answer: Active surveillance
Active surveillance is the answer. For low-risk prostate cancer, particularly in older patients or those with limited life expectancy, monitoring with serial prostate-specific antigen, examinations, and biopsies avoids the morbidity of treatment while reserving intervention for signs of progression. This recognizes that many low-grade tumors are indolent.
- A 67-year-old man with advanced metastatic prostate cancer is started on therapy designed to lower testosterone, the hormone that fuels tumor growth. Which treatment approach achieves this goal?
- Phosphodiesterase-5 inhibition
- Androgen deprivation therapy
- Alpha-blocker monotherapy
- 5-alpha-reductase inhibition alone
Correct answer: Androgen deprivation therapy
Androgen deprivation therapy is the answer. Because prostate cancer growth is androgen-dependent, lowering testosterone with a gonadotropin-releasing hormone agonist or antagonist, or with orchiectomy, slows progression of advanced disease. This hormonal approach is a cornerstone of metastatic prostate cancer management.
- A 70-year-old man with a long smoking history presents with painless gross hematuria but no pain, fever, or other symptoms. Which malignancy should be strongly suspected as the cause of this presentation?
- Bladder cancer
- Benign prostatic hyperplasia
- Acute cystitis
- Renal cyst
Correct answer: Bladder cancer
Bladder cancer is the answer. Painless gross hematuria in an older patient, especially a smoker, is the classic presentation of bladder cancer and warrants urgent evaluation. Smoking is the most important modifiable risk factor for the disease.
- A patient with painless hematuria is being evaluated for possible bladder cancer. Which procedure allows direct visualization of the bladder mucosa and tissue sampling to confirm the diagnosis?
- Cystoscopy with biopsy
- Renal ultrasound
- Voiding cystourethrogram
- Plain abdominal radiograph
Correct answer: Cystoscopy with biopsy
Cystoscopy with biopsy is the answer. Direct endoscopic inspection of the bladder lining permits identification and biopsy or resection of suspicious lesions, making it the standard for diagnosing bladder cancer. Imaging alone cannot sample tissue or detect small mucosal tumors reliably.
- A pathologist reports that a patient's bladder tumor is a urothelial carcinoma. From which lining cells of the urinary tract does this most common type of bladder cancer arise?
- Squamous epithelial cells
- Glandular columnar cells
- Transitional epithelial cells
- Neuroendocrine cells
Correct answer: Transitional epithelial cells
Transitional epithelial cells are the answer. Urothelial carcinoma, also called transitional cell carcinoma, arises from the transitional epithelium that lines the bladder and the rest of the urinary collecting system. This histology accounts for the large majority of bladder cancers in the United States.
- A 19-year-old man notices a soft, nontender scrotal mass that feels like a bag of worms above the left testis, more prominent when standing and decreasing when lying down. Which condition is most likely?
- Varicocele
- Hydrocele
- Testicular tumor
- Spermatocele
Correct answer: Varicocele
Varicocele is the answer. Dilation of the pampiniform venous plexus produces a soft, compressible bag-of-worms mass that enlarges with standing or Valsalva and decreases when supine. Most varicoceles occur on the left because of the venous drainage angle into the renal vein.
- A 1-year-old boy is found to have an empty right hemiscrotum, and a testis is palpable in the inguinal canal. Which condition does this describe, and why is correction recommended?
- Hydrocele, which requires no intervention
- Cryptorchidism, because of increased risks of infertility and testicular cancer
- Varicocele, because of venous congestion
- Epididymitis, requiring antibiotics
Correct answer: Cryptorchidism, because of increased risks of infertility and testicular cancer
Cryptorchidism, because of increased risks of infertility and testicular cancer, is the answer. An undescended testis should be surgically brought into the scrotum, typically by orchiopexy in infancy, to reduce later risks of impaired fertility and malignancy and to allow easier examination. Spontaneous descent after the first several months is unlikely.
- A 28-year-old man has a firm, painless, hard mass within the body of the testis that does not transilluminate. Which is the most appropriate initial diagnostic step?
- Reassurance and observation for one year
- Empiric antibiotics for presumed infection
- Fine-needle aspiration of the testis
- Scrotal ultrasound and measurement of serum tumor markers
Correct answer: Scrotal ultrasound and measurement of serum tumor markers
Scrotal ultrasound and measurement of serum tumor markers is the answer. A solid, painless intratesticular mass is concerning for testicular cancer, and ultrasound characterizes the lesion while markers such as alpha-fetoprotein, beta-hCG, and lactate dehydrogenase aid diagnosis and staging. Transscrotal needle biopsy is avoided because it risks tumor seeding.
- A 35-year-old man is being evaluated for infertility, and his semen analysis is abnormal. A physical finding of a left-sided varicocele is noted. Which mechanism best explains how a varicocele can impair spermatogenesis?
- Direct bacterial infection of the seminiferous tubules
- Autoimmune destruction of sperm
- Increased scrotal temperature from venous pooling
- Obstruction of the ejaculatory ducts
Correct answer: Increased scrotal temperature from venous pooling
Increased scrotal temperature from venous pooling is the answer. The dilated pampiniform plexus in a varicocele impairs the countercurrent cooling of the testis, raising local temperature and disrupting spermatogenesis. This is why varicocele is a common, potentially correctable cause of male infertility.
- A 2-year-old boy has a soft, fluctuant scrotal swelling that transilluminates brightly and is nontender. Which condition is most consistent with these findings?
- Hydrocele
- Testicular torsion
- Incarcerated hernia
- Orchitis
Correct answer: Hydrocele
Hydrocele is the answer. A nontender, fluid-filled scrotal swelling that transilluminates is characteristic of a hydrocele, a collection of serous fluid within the tunica vaginalis. Many congenital hydroceles resolve spontaneously during early childhood.
- A 60-year-old man reports the inability to achieve an erection adequate for intercourse, and he has diabetes and peripheral vascular disease. Which class of medication is considered first-line oral therapy for erectile dysfunction?
- Phosphodiesterase-5 inhibitors
- Alpha-blockers
- Beta-blockers
- Tricyclic antidepressants
Correct answer: Phosphodiesterase-5 inhibitors
Phosphodiesterase-5 inhibitors are the answer. Agents such as sildenafil enhance nitric oxide-mediated smooth muscle relaxation in the corpora cavernosa, making them first-line oral treatment for erectile dysfunction. They are contraindicated with nitrates because of the risk of severe hypotension.
- A 40-year-old man has a sustained, painful erection lasting more than four hours that is unrelated to sexual stimulation. Why does this condition require urgent evaluation and treatment?
- It is a normal variant requiring no intervention
- Prolonged ischemia can cause permanent erectile tissue damage
- It always resolves spontaneously within a day
- It indicates a urinary tract infection requiring antibiotics
Correct answer: Prolonged ischemia can cause permanent erectile tissue damage
Prolonged ischemia can cause permanent erectile tissue damage is the answer. Ischemic priapism is a urologic emergency because trapped, poorly oxygenated blood in the corpora cavernosa leads to tissue injury and fibrosis if not relieved promptly. Treatment includes aspiration and intracavernosal sympathomimetics to restore flow.
- A 36-year-old woman with iron deficiency anemia begins oral ferrous sulfate. To confirm an early therapeutic response before the hemoglobin has substantially recovered, which laboratory change is expected within about one week of starting treatment?
- A rise in the reticulocyte count
- A fall in the reticulocyte count
- An immediate normalization of the mean corpuscular volume
- A rise in serum ferritin to normal within days
Correct answer: A rise in the reticulocyte count
A rise in the reticulocyte count is the expected early sign of response, because once iron becomes available the marrow rapidly increases red cell production, producing a reticulocytosis within roughly five to ten days that precedes a meaningful rise in hemoglobin. The reticulocyte count does not fall with effective therapy, the mean corpuscular volume corrects only gradually as new normal-sized cells replace older microcytic ones, and ferritin stores take weeks to months to replenish.
- A 48-year-old woman with longstanding iron deficiency anemia reports an unusual craving to chew ice. Which term describes this ice-eating behavior associated with iron deficiency?
- Koilonychia
- Pagophagia
- Glossitis
- Angular cheilitis
Correct answer: Pagophagia
Pagophagia is the specific term for compulsive ice chewing, a form of pica strongly associated with iron deficiency that often resolves with iron repletion. Koilonychia refers to spoon-shaped nails, glossitis is a smooth inflamed tongue, and angular cheilitis is fissuring at the corners of the mouth; while these other physical findings can accompany iron deficiency, none of them describes the craving to chew ice.
- A 62-year-old woman has a microcytic anemia, and iron studies show a low serum iron with a transferrin saturation of 8 percent and a low ferritin. Which single calculated value most directly reflects the proportion of available transferrin binding sites occupied by iron?
- Reticulocyte index
- Mean corpuscular hemoglobin concentration
- Transferrin saturation
- Red cell distribution width
Correct answer: Transferrin saturation
Transferrin saturation most directly reflects the proportion of transferrin binding sites occupied by iron, since it is calculated as serum iron divided by total iron-binding capacity, and a low value such as 8 percent supports iron deficiency. The reticulocyte index gauges marrow response, the mean corpuscular hemoglobin concentration measures hemoglobin density within cells, and the red cell distribution width measures size variability, none of which expresses transferrin occupancy.
- A 58-year-old woman with chronic alcohol use and poor dietary intake has a macrocytic anemia with hypersegmented neutrophils, but her vitamin B12 level and neurologic examination are normal. Which deficiency most likely explains her megaloblastic anemia?
- Iron deficiency
- Vitamin K deficiency
- Copper deficiency
- Folate deficiency
Correct answer: Folate deficiency
Folate deficiency most likely explains a megaloblastic, macrocytic anemia with hypersegmented neutrophils when the vitamin B12 level and neurologic examination are normal, since folate deficiency, unlike vitamin B12 deficiency, does not cause neurologic damage. Poor intake and alcohol use are classic causes because body folate stores are small. Iron deficiency produces microcytosis, while vitamin K and copper deficiencies do not cause this megaloblastic picture.
- When distinguishing vitamin B12 deficiency from folate deficiency in a patient with megaloblastic anemia, which pair of metabolites is characteristically elevated in vitamin B12 deficiency but largely normal in isolated folate deficiency?
- Methylmalonic acid and homocysteine
- Lactate dehydrogenase and haptoglobin
- Ferritin and transferrin saturation
- D-dimer and fibrinogen
Correct answer: Methylmalonic acid and homocysteine
Methylmalonic acid and homocysteine are both characteristically elevated in vitamin B12 deficiency, whereas isolated folate deficiency raises homocysteine but leaves methylmalonic acid normal, making methylmalonic acid the more specific discriminator. Lactate dehydrogenase and haptoglobin track hemolysis, ferritin and transferrin saturation assess iron status, and D-dimer and fibrinogen reflect coagulation activity, none of which separates these two vitamin deficiencies.
- A 4-year-old boy of sub-Saharan African descent with sickle cell anemia has not received certain childhood vaccines and is being counseled on infection risk. A vaso-occlusive event in the small bones of his hands and feet causing painful, swollen digits in infancy is known by which name?
- Priapism
- Dactylitis
- Splenic sequestration
- Acute chest syndrome
Correct answer: Dactylitis
Dactylitis, also called hand-foot syndrome, is the painful swelling of the hands and feet caused by vaso-occlusion in the small bones, and it is frequently one of the earliest manifestations of sickle cell anemia in infancy. Priapism is a painful sustained erection from vaso-occlusion, splenic sequestration is pooling of blood in the spleen, and acute chest syndrome is a pulmonary complication, none of which describes the swollen digits.
- A 14-year-old boy with sickle cell anemia presents to the emergency department with a painful, sustained, and unwanted erection lasting more than four hours. Which complication of sickle cell disease does this represent?
- Avascular necrosis of the femoral head
- Aplastic crisis
- Priapism
- Cholelithiasis
Correct answer: Priapism
Priapism, a prolonged painful erection caused by sickling and vaso-occlusion within the corpora cavernosa, is a recognized urologic emergency in sickle cell disease that can lead to erectile dysfunction if untreated. Avascular necrosis of the femoral head is a chronic bone complication, aplastic crisis is a sudden drop in red cell production, and cholelithiasis results from chronic hemolysis producing pigment gallstones, none of which describes a sustained erection.
- A newborn screening hemoglobin study is reported as showing an FS pattern, meaning fetal hemoglobin and hemoglobin S are present without hemoglobin A. Which interpretation of this newborn result is most accurate?
- The infant has normal hemoglobin
- The infant has iron deficiency
- The infant has hemophilia A
- The infant has sickle cell anemia
Correct answer: The infant has sickle cell anemia
The infant has sickle cell anemia, because an FS pattern indicates fetal hemoglobin and hemoglobin S with a complete absence of normal adult hemoglobin A, meaning no normal beta-globin is being produced. This contrasts with sickle cell trait, which shows hemoglobins F, A, and S together. The pattern is not normal, and it has nothing to do with iron deficiency or hemophilia, which are not detected on hemoglobin electrophoresis.
- A 30-year-old woman is the daughter of a man with hemophilia A and a mother with no bleeding disorder. Considering the X-linked recessive inheritance of hemophilia A, what is this woman's carrier status?
- She is an obligate carrier of the hemophilia A gene
- She cannot be a carrier because she is female
- She will definitely have severe hemophilia A herself
- Her carrier status is impossible to predict from this information
Correct answer: She is an obligate carrier of the hemophilia A gene
She is an obligate carrier because a father with hemophilia A passes his single affected X chromosome to all of his daughters, making every daughter a carrier of the gene. Females can certainly be carriers, and most carriers are not severely affected because they have a second normal X chromosome. Her status is fully predictable from the inheritance pattern, so it is neither impossible to determine nor a certainty of severe disease.
- A patient with thrombotic thrombocytopenic purpura is diagnosed based on microangiopathic hemolytic anemia and severe thrombocytopenia. Which intervention is the most important and urgent treatment for this condition?
- Platelet transfusion
- Plasma exchange
- Splenectomy
- Intravenous iron
Correct answer: Plasma exchange
Plasma exchange is the most important and urgent treatment for thrombotic thrombocytopenic purpura because it removes the inhibitor of ADAMTS13 and replenishes the deficient enzyme, dramatically reducing mortality. Platelet transfusion is generally avoided because it can fuel further microthrombi, splenectomy is not the acute intervention, and intravenous iron does not address the underlying enzyme deficiency driving the microangiopathy.
- A hospitalized patient on heparin is being evaluated for possible heparin-induced thrombocytopenia. Which laboratory test detects the antibodies directed against the heparin-platelet factor 4 complex that drive this disorder?
- A peripheral blood smear for schistocytes
- A direct antiglobulin test
- A platelet factor 4 antibody immunoassay
- A serum ferritin level
Correct answer: A platelet factor 4 antibody immunoassay
A platelet factor 4 antibody immunoassay detects the antibodies against the heparin-platelet factor 4 complex that mediate heparin-induced thrombocytopenia, and a positive result supports the diagnosis when clinical suspicion is high. A smear for schistocytes evaluates microangiopathy, a direct antiglobulin test detects antibody-coated red cells in autoimmune hemolysis, and serum ferritin assesses iron stores, none of which identifies the heparin-platelet factor 4 antibodies.
- A 6-year-old with newly diagnosed immune thrombocytopenic purpura has wet purpura with active mucosal bleeding and a very low platelet count. Which therapy raises the platelet count most rapidly when urgent control of bleeding is needed?
- Oral iron supplementation
- Low-molecular-weight heparin
- Vitamin K
- Intravenous immunoglobulin
Correct answer: Intravenous immunoglobulin
Intravenous immunoglobulin raises the platelet count most rapidly in immune thrombocytopenic purpura with active bleeding, because it transiently blocks splenic macrophage clearance of antibody-coated platelets, often producing a response within a day or two. Oral iron addresses anemia, heparin is an anticoagulant that would worsen bleeding, and vitamin K corrects clotting factor deficiencies rather than a platelet destruction disorder.
- A 25-year-old woman with von Willebrand disease is undergoing confirmatory testing. Which laboratory assay specifically measures the ability of von Willebrand factor to support platelet binding and is reduced in this disorder?
- Ristocetin cofactor activity
- Prothrombin time
- Reticulocyte count
- Serum haptoglobin
Correct answer: Ristocetin cofactor activity
Ristocetin cofactor activity specifically measures the functional capacity of von Willebrand factor to mediate platelet binding, and it is characteristically reduced in von Willebrand disease, making it a key confirmatory assay. The prothrombin time evaluates the extrinsic pathway and is typically normal, the reticulocyte count measures marrow red cell output, and haptoglobin reflects hemolysis, none of which assesses von Willebrand factor function.
- A 19-year-old man with mild hemophilia B requires preparation for an elective procedure. Because hemophilia B is caused by deficiency of a specific factor, which replacement product is appropriate to correct his coagulopathy?
- Factor VIII concentrate
- Factor IX concentrate
- Desmopressin
- Platelet transfusion
Correct answer: Factor IX concentrate
Factor IX concentrate is appropriate because hemophilia B results from a deficiency of factor IX, so replacing that specific factor restores the intrinsic pathway and corrects the bleeding tendency. Factor VIII concentrate treats hemophilia A rather than hemophilia B, desmopressin is useful in mild hemophilia A and von Willebrand disease but does not raise factor IX, and platelets are normal in hemophilia and would not help.
- A peripheral blood smear in a patient with suspected hemolysis shows numerous spherical red cells, and the clinician wishes to determine whether the hemolysis is immune-mediated. A positive result on which test would establish an autoimmune cause?
- Osmotic fragility test
- Hemoglobin electrophoresis
- Direct antiglobulin test
- Serum ferritin
Correct answer: Direct antiglobulin test
A positive direct antiglobulin test would establish an autoimmune cause, because spherocytes can result from antibody-mediated red cell injury, and the test detects immunoglobulin or complement on the red cell surface. An osmotic fragility test would be increased in both immune and hereditary spherocytosis and does not establish immunity, hemoglobin electrophoresis evaluates hemoglobinopathies, and serum ferritin assesses iron stores rather than immune hemolysis.
- A 68-year-old man with a chronic anemia is found to have cold agglutinins, and his hemolysis worsens in cold conditions with a direct antiglobulin test positive for complement. Which underlying infection is a classic precipitant of cold agglutinin hemolytic anemia?
- Group A streptococcal pharyngitis
- Rotavirus gastroenteritis
- Hepatitis A infection
- Mycoplasma pneumoniae infection
Correct answer: Mycoplasma pneumoniae infection
Mycoplasma pneumoniae infection is a classic precipitant of cold agglutinin hemolytic anemia, in which immunoglobulin M antibodies bind red cells and fix complement at lower temperatures, causing hemolysis that worsens with cold exposure. Group A streptococcal pharyngitis, rotavirus gastroenteritis, and hepatitis A are not characteristically associated with cold agglutinin disease, which is most often linked to mycoplasma and Epstein-Barr virus infections.
- A hematologist explains that some hemolytic anemias destroy red cells primarily within the spleen and liver while others rupture cells within the circulation. Which finding most specifically points to intravascular rather than extravascular hemolysis?
- Hemoglobinuria
- Splenomegaly
- Elevated indirect bilirubin alone
- Spherocytes on the smear
Correct answer: Hemoglobinuria
Hemoglobinuria most specifically points to intravascular hemolysis, because when red cells rupture inside the bloodstream, free hemoglobin is released, saturates haptoglobin, and spills into the urine. Splenomegaly and spherocytes are more typical of extravascular hemolysis in which macrophages remove damaged cells, and an isolated elevated indirect bilirubin occurs in both forms, so none of those distinguishes the intravascular process as clearly as hemoglobinuria.
- A 22-year-old man with G6PD deficiency is about to travel to a malaria-endemic region. Which precaution is most appropriate given that certain antimalarial drugs can trigger hemolysis in this enzyme deficiency?
- Give a double dose of any antimalarial to ensure efficacy
- Confirm G6PD status before prescribing an oxidant antimalarial such as primaquine
- Begin prophylactic blood transfusions before travel
- Restrict dietary iron during travel
Correct answer: Confirm G6PD status before prescribing an oxidant antimalarial such as primaquine
Confirming G6PD status before prescribing an oxidant antimalarial such as primaquine is most appropriate, because primaquine and related oxidant drugs can precipitate acute hemolysis in patients lacking adequate G6PD, so testing guides safe drug selection. Doubling the dose would increase oxidative stress, prophylactic transfusions are unnecessary and risky, and iron restriction does not influence oxidative hemolysis in this enzyme deficiency.
- A medical student asks how glucose-6-phosphate dehydrogenase deficiency is passed in families, noting that it overwhelmingly affects males. Which inheritance pattern explains this male predominance?
- Autosomal dominant
- Autosomal recessive
- X-linked recessive
- Mitochondrial
Correct answer: X-linked recessive
X-linked recessive inheritance explains the male predominance of glucose-6-phosphate dehydrogenase deficiency, because males have a single X chromosome and are fully affected if it carries the variant, whereas females usually require two affected copies to show significant disease. Autosomal dominant and recessive patterns would affect the sexes more equally, and mitochondrial inheritance would be transmitted exclusively through the mother to all offspring.
- A 28-year-old woman with disseminated intravascular coagulation from severe sepsis continues to bleed and clot despite supportive care. Which intervention is the most fundamental to controlling the coagulopathy?
- Starting long-term warfarin therapy
- Performing an urgent splenectomy
- Beginning iron supplementation
- Treating the underlying precipitating condition
Correct answer: Treating the underlying precipitating condition
Treating the underlying precipitating condition is the most fundamental intervention in disseminated intravascular coagulation, because the consumptive process is driven by the trigger, such as sepsis, and controlling that source is essential for the coagulopathy to resolve, with blood product support given as needed. Long-term warfarin, splenectomy, and iron supplementation do not address the systemic activation of coagulation that defines this disorder.
- A 26-year-old man with Hodgkin lymphoma is noted to have an atypical symptom of pain in his involved lymph nodes shortly after drinking alcohol. Within which age and demographic pattern does classic Hodgkin lymphoma characteristically present?
- A bimodal age distribution with peaks in young adults and older adults
- Exclusively in infants under one year of age
- Only in adults over the age of eighty
- Equally across every age with no peak
Correct answer: A bimodal age distribution with peaks in young adults and older adults
Classic Hodgkin lymphoma characteristically shows a bimodal age distribution, with one peak in young adults and a second peak in older adults, which is a distinctive epidemiologic feature of the disease. It does not occur exclusively in infants, is not limited to the very elderly, and does not present uniformly across all ages, making the bimodal pattern the defining demographic description.
- A 5-year-old child with acute lymphoblastic leukemia has marrow blasts that stain positive for terminal deoxynucleotidyl transferase. Which feature of this finding supports the diagnosis of a lymphoblastic rather than a myeloid leukemia?
- Terminal deoxynucleotidyl transferase indicates mature plasma cells
- Terminal deoxynucleotidyl transferase is a marker of immature lymphoid cells
- Terminal deoxynucleotidyl transferase confirms a myeloid lineage
- Terminal deoxynucleotidyl transferase is specific for red cell precursors
Correct answer: Terminal deoxynucleotidyl transferase is a marker of immature lymphoid cells
Terminal deoxynucleotidyl transferase is a marker of immature lymphoid cells, so its positivity in the blasts supports a lymphoblastic leukemia and helps distinguish acute lymphoblastic leukemia from acute myeloid leukemia. It does not indicate mature plasma cells, does not confirm a myeloid lineage, and is not a red cell precursor marker, all of which would point away from the lymphoblastic diagnosis.
- A 70-year-old man with newly diagnosed multiple myeloma has a peripheral smear that shows red cells stacked in linear aggregates resembling a column of coins. Which term describes this smear finding caused by the high level of circulating monoclonal protein?
- Schistocytes
- Target cells
- Rouleaux formation
- Spherocytes
Correct answer: Rouleaux formation
Rouleaux formation describes red cells stacked like a column of coins, which occurs in multiple myeloma because the high concentration of monoclonal immunoglobulin reduces the normal repulsion between red cells and lets them aggregate. Schistocytes are fragmented cells from microangiopathy, target cells are seen in thalassemia and liver disease, and spherocytes occur in hemolytic states, none of which is produced by excess monoclonal protein.
- A patient with polycythemia vera has an elevated red cell mass and a history of thrombosis. Beyond therapeutic phlebotomy to control the hematocrit, which low-dose medication is commonly added to reduce thrombotic risk in this disorder?
- Warfarin
- Desmopressin
- Factor IX concentrate
- Low-dose aspirin
Correct answer: Low-dose aspirin
Low-dose aspirin is commonly added in polycythemia vera to reduce the elevated risk of arterial and venous thrombosis, complementing phlebotomy that lowers the hematocrit. Warfarin is not the standard routine antithrombotic for uncomplicated polycythemia vera, desmopressin promotes hemostasis and would be counterproductive, and factor IX concentrate treats hemophilia B, neither of which addresses the thrombotic tendency of this myeloproliferative neoplasm.
- A 45-year-old man with no symptoms is found to have a persistently elevated transferrin saturation and ferritin, and genetic testing reveals a hereditary disorder of excessive intestinal iron absorption. Which condition does this represent?
- Hereditary hemochromatosis
- Iron deficiency anemia
- Anemia of chronic disease
- Sideroblastic anemia
Correct answer: Hereditary hemochromatosis
Hereditary hemochromatosis is represented by inappropriately high transferrin saturation and ferritin from excessive intestinal iron absorption, leading to iron deposition in the liver, heart, pancreas, and joints over time. Iron deficiency anemia shows low iron stores, anemia of chronic disease shows low serum iron with high ferritin from inflammation rather than overload, and sideroblastic anemia involves defective heme synthesis rather than excessive absorption.
- A patient with hereditary hemochromatosis and a high iron burden but a normal hemoglobin is referred for treatment. Which intervention is the standard first-line therapy to remove excess iron in this setting?
- Oral iron supplementation
- Therapeutic phlebotomy
- Regular red cell transfusions
- Erythropoietin injections
Correct answer: Therapeutic phlebotomy
Therapeutic phlebotomy is the standard first-line therapy for hereditary hemochromatosis in a patient who is not anemic, because regularly removing blood depletes the excess body iron and prevents organ damage. Oral iron and transfusions would add iron and worsen overload, and erythropoietin would stimulate red cell production and increase iron utilization rather than safely removing the stored excess.
- A clinician evaluating an anemia first classifies it by the mean corpuscular volume. A macrocytic anemia with a mean corpuscular volume above 100 fL should prompt consideration of which group of causes?
- Iron deficiency and thalassemia trait
- Acute blood loss with a normal marrow
- Vitamin B12 deficiency, folate deficiency, and alcohol use
- Lead poisoning and sideroblastic anemia
Correct answer: Vitamin B12 deficiency, folate deficiency, and alcohol use
Vitamin B12 deficiency, folate deficiency, and alcohol use are leading causes of a macrocytic anemia with a mean corpuscular volume above 100 fL, since impaired DNA synthesis or alcohol effects enlarge the red cells. Iron deficiency and thalassemia trait cause microcytosis, acute blood loss is typically normocytic, and lead poisoning and sideroblastic anemia more often cause a microcytic picture, so those do not fit the macrocytic category.
- A patient with anemia has a reticulocyte count that is inappropriately low for the degree of anemia. What does this finding most directly indicate about the bone marrow?
- The marrow is over-responding to the anemia
- The red cells are being destroyed faster than normal in the periphery
- The patient has an acute blood loss with a vigorous marrow
- The marrow is failing to mount an adequate compensatory response
Correct answer: The marrow is failing to mount an adequate compensatory response
An inappropriately low reticulocyte count for the degree of anemia most directly indicates that the marrow is failing to mount an adequate compensatory response, as seen in hypoproliferative anemias such as iron, vitamin B12, or folate deficiency or marrow failure. An over-responding marrow or peripheral destruction would raise the reticulocyte count, and brisk blood loss with a healthy marrow likewise produces reticulocytosis, so a low count signals inadequate production.
- A 33-year-old woman is found to have a mild microcytic anemia. Which initial set of studies best distinguishes iron deficiency anemia from thalassemia trait, the two most common causes of microcytosis?
- Iron studies, with hemoglobin electrophoresis if iron studies are normal
- A direct antiglobulin test alone
- Vitamin B12 and folate levels
- A bone marrow biopsy as the first step
Correct answer: Iron studies, with hemoglobin electrophoresis if iron studies are normal
Iron studies, followed by hemoglobin electrophoresis when iron studies are normal, best distinguish the two leading causes of microcytosis, because iron deficiency shows depleted iron stores while thalassemia trait shows normal iron with an abnormal electrophoresis. A direct antiglobulin test evaluates immune hemolysis, vitamin B12 and folate assess macrocytic anemia, and a bone marrow biopsy is unnecessarily invasive as an initial step for microcytic anemia.
- A clinician explains to a student that the activated partial thromboplastin time and the prothrombin time assess different limbs of the coagulation cascade. The prothrombin time primarily evaluates which pathway?
- The intrinsic pathway
- The extrinsic pathway
- Platelet adhesion
- Fibrinolysis
Correct answer: The extrinsic pathway
The prothrombin time primarily evaluates the extrinsic pathway, which depends on tissue factor and factor VII, whereas the activated partial thromboplastin time evaluates the intrinsic pathway involving factors such as VIII, IX, XI, and XII. The prothrombin time does not directly measure platelet adhesion, which is assessed by platelet function studies, nor does it measure fibrinolysis, which is reflected by tests such as D-dimer.
- A 6-month-old infant fed primarily goat milk presents with pallor and a macrocytic anemia. Which nutritional deficiency is classically associated with a goat-milk-predominant diet causing megaloblastic anemia?
- Iron deficiency
- Vitamin K deficiency
- Folate deficiency
- Zinc deficiency
Correct answer: Folate deficiency
Folate deficiency is classically associated with a goat-milk-predominant diet, because goat milk is notably low in folate, and infants fed it as a primary food can develop a megaloblastic, macrocytic anemia. Iron deficiency causes microcytosis and is more linked to cow-milk-predominant diets, vitamin K deficiency causes bleeding rather than megaloblastic anemia, and zinc deficiency does not produce this red cell picture.
- A 24-year-old man of West African descent is asymptomatic, and hemoglobin electrophoresis shows hemoglobins A and S with hemoglobin A predominating and a normal blood count. Which condition does this pattern represent?
- Sickle cell anemia
- Beta thalassemia major
- Iron deficiency anemia
- Sickle cell trait
Correct answer: Sickle cell trait
Sickle cell trait is represented by a healthy carrier with both hemoglobin A and hemoglobin S on electrophoresis, with hemoglobin A predominating and a normal blood count, reflecting one normal and one sickle beta-globin gene. Sickle cell anemia shows hemoglobin S without normal hemoglobin A, beta thalassemia major shows severe anemia with little or no hemoglobin A, and iron deficiency is not detected on hemoglobin electrophoresis.
- A patient develops cyanosis unresponsive to supplemental oxygen and chocolate-brown blood after exposure to an oxidizing agent such as dapsone, with a pulse oximetry reading that does not match the clinical picture. Which condition does this presentation most likely represent?
- Methemoglobinemia
- Iron deficiency anemia
- Polycythemia vera
- Hemophilia A
Correct answer: Methemoglobinemia
Methemoglobinemia most likely explains cyanosis that does not improve with oxygen, chocolate-brown blood, and a pulse oximetry reading discordant with the clinical state, because oxidized iron in hemoglobin cannot carry oxygen, and oxidizing drugs such as dapsone are common triggers. Iron deficiency anemia, polycythemia vera, and hemophilia A do not produce oxidant-induced methemoglobin with this characteristic refractory cyanosis and abnormal blood color.
- A 28-year-old woman in Wisconsin is seen in July for a 5-cm expanding red patch on her flank that is warm but not painful or itchy. She recalls removing an attached tick about ten days earlier. Which clinical action is most appropriate at this visit?
- Begin oral doxycycline based on the clinical diagnosis of erythema migrans
- Order two-tier serology and withhold treatment until results return
- Excise the lesion and send it for histopathology
- Reassure the patient that the lesion is a simple local bite reaction
Correct answer: Begin oral doxycycline based on the clinical diagnosis of erythema migrans
Beginning oral doxycycline is correct because early localized Lyme disease with classic erythema migrans is a clinical diagnosis that does not require serologic confirmation. Serology is often negative this early because antibodies have not yet developed, so waiting for testing delays effective therapy. Excision is unnecessary, and dismissing an expanding annular lesion after a known tick exposure as a simple bite reaction would miss a treatable spirochetal infection.
- A 50-year-old man who hikes frequently in the northeastern United States presents with several weeks of intermittent palpitations and lightheadedness. An electrocardiogram shows third-degree atrioventricular block, and he recently had a flu-like illness. Which infection should be strongly considered as the cause of this conduction abnormality?
- Rocky Mountain spotted fever
- Lyme disease
- Infectious mononucleosis
- Malaria
Correct answer: Lyme disease
Lyme disease is the most likely cause because early disseminated Lyme can produce Lyme carditis, which characteristically causes fluctuating, often high-grade atrioventricular block in a patient with relevant tick exposure. The conduction disease is usually reversible with appropriate antibiotic therapy and sometimes temporary pacing. Rocky Mountain spotted fever, mononucleosis, and malaria are not typical causes of complete heart block.
- A 12-year-old boy who lives in an endemic region develops a swollen, minimally painful knee with a moderate effusion several months after an untreated summer illness that included a rash. Lyme serology is strongly positive on two-tier testing. Which description best fits this manifestation?
- Reactive arthritis triggered by a recent gastrointestinal infection
- Septic arthritis requiring urgent joint washout
- Late Lyme arthritis, typically a monoarticular or oligoarticular large-joint effusion
- Acute rheumatic fever with migratory polyarthritis
Correct answer: Late Lyme arthritis, typically a monoarticular or oligoarticular large-joint effusion
Late Lyme arthritis is the best fit because untreated Lyme disease can progress over months to a swollen large joint, most often the knee, with a relatively large effusion and surprisingly modest pain. The positive two-tier serology and prior tick-associated illness support the diagnosis, which is treated with oral or intravenous antibiotics. Septic arthritis is acutely painful and toxic, reactive arthritis follows specific enteric or genitourinary infections, and rheumatic fever causes migratory polyarthritis after streptococcal pharyngitis.
- A clinician is teaching a patient about reducing the risk of Lyme disease after outdoor activity in an endemic area. Which statement reflects an accurate prevention principle?
- Transmission occurs instantly, so any attached tick guarantees infection
- Only adult ticks, not nymphs, are capable of transmitting the spirochete
- Oral antibiotics should be taken daily throughout tick season as routine prophylaxis
- Prompt removal of an attached tick within roughly 24 to 36 hours markedly lowers transmission risk
Correct answer: Prompt removal of an attached tick within roughly 24 to 36 hours markedly lowers transmission risk
Prompt tick removal is correct because Borrelia transmission generally requires the Ixodes tick to remain attached for a prolonged period, often 24 to 36 hours or more, so early removal substantially reduces risk. Infection is not instantaneous, routine season-long antibiotics are not recommended, and nymphal ticks are actually responsible for most human infections because they are small and easily missed.
- A 20-year-old college athlete with recent infectious mononucleosis returns for clearance to resume football. Which factor most appropriately guides the timing of his return to contact play?
- Resolution of splenomegaly and being at least several weeks out from symptom onset
- Normalization of his serum heterophile antibody titer
- Complete disappearance of atypical lymphocytes from the blood smear
- A single afebrile day after starting therapy
Correct answer: Resolution of splenomegaly and being at least several weeks out from symptom onset
Resolution of splenomegaly combined with adequate time from symptom onset is the appropriate guide because the major catastrophic risk in mononucleosis is splenic rupture, which is highest in the first weeks of illness. Contact sports are generally withheld for at least three to four weeks and until the spleen is no longer enlarged. Heterophile titers and atypical lymphocytes can persist and do not track injury risk, and one afebrile day is insufficient.
- A 16-year-old with sore throat, fever, and fatigue has tonsillar exudates and tender posterior cervical nodes. A rapid streptococcal antigen test is negative, and a monospot is initially negative on day 3 of illness. Which next step is most appropriate if mononucleosis is still strongly suspected?
- Immediately start ampicillin to cover presumed bacterial pharyngitis
- Repeat the heterophile test later in the illness or obtain EBV-specific antibody titers
- Conclude the illness is noninfectious and discharge without follow-up
- Order a throat culture for fungal organisms
Correct answer: Repeat the heterophile test later in the illness or obtain EBV-specific antibody titers
Repeating the heterophile test later or obtaining EBV-specific serology is correct because the monospot is frequently falsely negative in the first week before adequate antibody develops, so early testing can miss the diagnosis. EBV viral capsid antigen IgM is more reliable early on. Empiric ampicillin risks a morbilliform rash if the illness is EBV, dismissing the case ignores a recognized infection, and fungal culture is not indicated.
- A patient with infectious mononucleosis has tonsils so enlarged that they nearly meet in the midline, with muffled voice and difficulty managing secretions, but no abscess. Which intervention is most appropriate for this severe tonsillar swelling and threatened airway?
- A course of oral acyclovir to eradicate the virus
- Immediate tonsillectomy under general anesthesia
- A short course of systemic corticosteroids
- Intravenous immune globulin
Correct answer: A short course of systemic corticosteroids
A short course of systemic corticosteroids is appropriate because they reduce marked tonsillar and pharyngeal swelling that threatens the airway in severe mononucleosis. Antivirals such as acyclovir do not meaningfully alter the clinical course of EBV mononucleosis, urgent tonsillectomy is not the first-line response to inflammatory swelling, and intravenous immune globulin has no established role in routine mononucleosis.
- A previously healthy young adult is diagnosed with infectious mononucleosis. Which complication is the most common hematologic finding associated with this EBV infection?
- Eosinophilia exceeding 50 percent
- Pancytopenia from bone marrow aplasia
- Polycythemia
- Mild autoimmune hemolytic anemia or thrombocytopenia
Correct answer: Mild autoimmune hemolytic anemia or thrombocytopenia
Mild autoimmune hemolytic anemia or thrombocytopenia is the most common hematologic complication because EBV can trigger transient antibody-mediated destruction of red cells (often cold-agglutinin associated) or platelets. These cytopenias are usually self-limited. Marrow aplasia is rare, polycythemia is not a feature of mononucleosis, and the typical blood picture shows lymphocytosis with atypical lymphocytes rather than marked eosinophilia.
- A 7-year-old from Oklahoma is brought in during the summer with three days of high fever, severe headache, and abdominal pain. The parents removed a tick last week. A faint rash is just starting on the wrists and ankles. Which laboratory pattern most supports Rocky Mountain spotted fever?
- Thrombocytopenia and hyponatremia with normal or low white blood cell count
- Leukocytosis with marked eosinophilia and high IgE
- Isolated elevation of serum lipase
- Microcytic anemia with low ferritin
Correct answer: Thrombocytopenia and hyponatremia with normal or low white blood cell count
Thrombocytopenia with hyponatremia and a typically normal or low white blood cell count is the characteristic laboratory pattern of Rocky Mountain spotted fever, reflecting the small-vessel vasculitis and platelet consumption caused by Rickettsia rickettsii. Eosinophilia with high IgE suggests parasitic or allergic disease, isolated lipase elevation suggests pancreatitis, and microcytic anemia with low ferritin reflects iron deficiency, none of which fit this presentation.
- A clinician strongly suspects Rocky Mountain spotted fever in a febrile child, but the early indirect immunofluorescence antibody titer is not yet diagnostic. Which course of action is most appropriate?
- Withhold antibiotics until convalescent serology confirms the diagnosis
- Start empiric doxycycline immediately based on clinical suspicion
- Treat with intravenous penicillin while awaiting results
- Begin chloramphenicol only if the patient develops shock
Correct answer: Start empiric doxycycline immediately based on clinical suspicion
Starting empiric doxycycline immediately is correct because Rocky Mountain spotted fever is a clinical diagnosis and early serology is often negative, so treatment must not be delayed for confirmation. Mortality rises sharply when therapy begins after the fifth day of illness. Penicillin is ineffective against Rickettsia, and chloramphenicol is a less preferred alternative reserved for specific situations such as pregnancy, not something to delay until shock develops.
- A medical team reviews why doxycycline is recommended for children with suspected Rocky Mountain spotted fever despite traditional concerns about tetracyclines in young patients. Which statement best reflects current understanding?
- Doxycycline causes permanent tooth staining even after a single short course in children
- Children should receive amoxicillin instead because it is equally effective
- A short course of doxycycline is the treatment of choice at any age because the benefit clearly outweighs the minimal staining risk
- Doxycycline is contraindicated under age 8 and ciprofloxacin should be substituted
Correct answer: A short course of doxycycline is the treatment of choice at any age because the benefit clearly outweighs the minimal staining risk
A short course of doxycycline at any age is correct because evidence shows that the brief courses used for Rocky Mountain spotted fever do not cause clinically significant dental staining, and doxycycline is the only drug proven to reduce mortality from this disease. Amoxicillin and fluoroquinolones are not effective rickettsial therapy, and withholding the effective drug over outdated staining concerns can be fatal.
- A returning visitor to the southeastern United States develops Rocky Mountain spotted fever that progresses to confusion, oliguria, and respiratory distress. Which complication best explains this multiorgan picture?
- Direct bacterial toxin damaging the liver only
- Obstruction of bile flow causing systemic cholestasis
- An IgE-mediated anaphylactic cascade
- Widespread endothelial injury producing increased vascular permeability and multiorgan dysfunction
Correct answer: Widespread endothelial injury producing increased vascular permeability and multiorgan dysfunction
Widespread endothelial injury is the correct explanation because Rickettsia rickettsii invades and damages vascular endothelium throughout the body, leading to capillary leak, edema, and impaired perfusion that can cause encephalitis, acute kidney injury, and noncardiogenic pulmonary edema. An isolated hepatic toxin, anaphylaxis, and biliary obstruction do not account for the diffuse small-vessel, multiorgan pathology of severe spotted fever.
- A 38-year-old recent immigrant has a positive interferon-gamma release assay and a chest radiograph showing a calcified granuloma with a calcified hilar lymph node but no active infiltrate, and he is asymptomatic. Which term best describes this radiographic finding?
- Ghon complex consistent with healed primary tuberculosis
- Active cavitary reactivation tuberculosis
- Miliary tuberculosis
- Tuberculous empyema
Correct answer: Ghon complex consistent with healed primary tuberculosis
A Ghon complex consistent with healed primary tuberculosis is correct because a calcified parenchymal focus together with a calcified draining hilar node represents the healed remnant of a prior primary infection. The patient is asymptomatic with a positive immune test, indicating latent infection rather than active disease. Cavitary reactivation, miliary spread, and empyema are all features of active tuberculosis, which this stable calcified picture does not represent.
- A patient with HIV and a CD4 count of 90 develops fever, cough, and weight loss, but the tuberculin skin test is nonreactive. Which explanation best accounts for the negative skin test in this setting?
- The patient definitively does not have tuberculosis
- Advanced immunosuppression can cause a false-negative (anergic) tuberculin response
- A nonreactive test rules out the need for further evaluation
- The skin test is only valid in patients who have received BCG vaccination
Correct answer: Advanced immunosuppression can cause a false-negative (anergic) tuberculin response
Advanced immunosuppression causing anergy is the best explanation because the tuberculin skin test depends on a functioning cell-mediated immune response, which is blunted in advanced HIV, producing false-negative results even with true infection. A negative test therefore cannot exclude tuberculosis in this high-risk, symptomatic patient, who needs sputum studies and chest imaging. BCG affects test interpretation differently and does not validate the test.
- A patient on rifampin, isoniazid, pyrazinamide, and ethambutol for active tuberculosis develops nausea, right upper quadrant pain, and markedly elevated transaminases after several weeks. Which management step is most appropriate?
- Continue all four drugs because hepatotoxicity is expected and harmless
- Add acetaminophen for the abdominal pain and continue the regimen
- Hold the hepatotoxic agents and evaluate liver function before reintroducing therapy
- Switch the entire regimen to a single fluoroquinolone
Correct answer: Hold the hepatotoxic agents and evaluate liver function before reintroducing therapy
Holding the hepatotoxic agents and assessing liver function is correct because isoniazid, rifampin, and pyrazinamide can each cause drug-induced hepatitis, and significant transaminase elevation with symptoms warrants stopping the offending drugs and monitoring before careful reintroduction. Continuing despite clinical hepatotoxicity is unsafe, adding acetaminophen could worsen liver injury, and abruptly replacing the regimen with monotherapy risks resistance and inadequate treatment.
- A patient with active pulmonary tuberculosis is started on standard therapy and asks how the team will know when he is no longer contagious to family members. Which response is most accurate?
- He is noninfectious as soon as the first dose is taken
- Contagiousness is judged solely by resolution of the chest radiograph
- He will remain contagious for the entire six-month course regardless of treatment
- Reduced infectiousness generally follows adequate treatment, clinical improvement, and serial negative sputum acid-fast smears
Correct answer: Reduced infectiousness generally follows adequate treatment, clinical improvement, and serial negative sputum acid-fast smears
Reduced infectiousness following effective treatment, clinical improvement, and serial negative sputum smears is correct because these markers together indicate a substantial drop in the burden of viable, transmissible bacilli. A single dose does not render a patient noninfectious, patients typically become much less contagious within weeks of effective therapy rather than staying contagious for the full course, and radiographic changes lag and are not the sole criterion.
- A 26-year-old man requests testing after unprotected exposure. He has no symptoms, but a treponemal enzyme immunoassay is reactive while the follow-up nontreponemal RPR is nonreactive, and a second treponemal test is also reactive. Which interpretation is most consistent with these reverse-sequence screening results?
- Previously treated or late latent syphilis
- A biologic false-positive screen with no evidence of syphilis
- Active primary syphilis with a chancre
- A laboratory error requiring no follow-up
Correct answer: Previously treated or late latent syphilis
Previously treated or late latent syphilis is the best interpretation because in reverse-sequence screening a reactive treponemal test confirmed by a second treponemal test, with a nonreactive nontreponemal test, typically indicates past infection that was treated or long-standing latent disease, since treponemal antibodies persist for life while nontreponemal titers fall. A discordant pattern confirmed by a second treponemal test argues against a simple false positive, and the absence of a chancre and lack of recent infection do not fit active primary disease.
- A pregnant woman with a penicillin allergy is diagnosed with secondary syphilis. Which management approach is recommended?
- Substitute doxycycline because it is safe in pregnancy
- Perform penicillin allergy evaluation and desensitization so penicillin can be given
- Treat with a single dose of oral azithromycin
- Defer all treatment until after delivery
Correct answer: Perform penicillin allergy evaluation and desensitization so penicillin can be given
Penicillin desensitization is recommended because penicillin is the only therapy proven to reliably treat syphilis in pregnancy and to prevent congenital syphilis, so an allergic pregnant patient should be desensitized rather than given an alternative. Doxycycline is contraindicated in pregnancy, azithromycin has resistance concerns and is not recommended in pregnancy, and deferring treatment endangers the fetus.
- A patient with confirmed syphilis reports new headaches, visual changes, and difficulty hearing. The clinician is concerned about central nervous system involvement. Which test is most appropriate to evaluate for neurosyphilis?
- Brain magnetic resonance imaging alone
- A repeat serum RPR titer only
- Lumbar puncture with cerebrospinal fluid analysis including VDRL
- Electroencephalography
Correct answer: Lumbar puncture with cerebrospinal fluid analysis including VDRL
Lumbar puncture with cerebrospinal fluid analysis, including a CSF-VDRL along with cell count and protein, is most appropriate because neurosyphilis is diagnosed by examining the spinal fluid in a patient with syphilis and neurologic or ophthalmic or otic symptoms. Imaging and electroencephalography may support evaluation but do not establish the diagnosis, and a serum titer alone cannot confirm central nervous system invasion.
- A clinician is monitoring response to therapy in a patient treated for secondary syphilis. Which laboratory result best indicates an adequate treatment response over the following months?
- Conversion of the treponemal test from reactive to nonreactive
- Persistence of an unchanged RPR titer at one year
- A rising nontreponemal titer
- A fourfold (two-dilution) decline in the nontreponemal RPR titer
Correct answer: A fourfold (two-dilution) decline in the nontreponemal RPR titer
A fourfold decline in the nontreponemal RPR titer is the correct marker because nontreponemal titers fall with successful treatment and a two-dilution drop signifies an adequate response. Treponemal tests usually stay reactive for life and are not used to track response. A rising titer suggests treatment failure or reinfection, and an unchanged or insufficiently declining titer raises concern for inadequate treatment.
- A 65-year-old nursing home resident is brought in with new confusion, a temperature of 38.9 degrees Celsius, heart rate of 118, respiratory rate of 26, and blood pressure of 92/58. A urinary tract source is suspected. Which framework best characterizes this presentation as a medical emergency?
- Sepsis with organ dysfunction from a presumed urinary source
- Uncomplicated lower urinary tract infection
- Isolated delirium unrelated to infection
- Simple dehydration without infection
Correct answer: Sepsis with organ dysfunction from a presumed urinary source
Sepsis with organ dysfunction is the correct characterization because the patient has a suspected infection plus acute organ dysfunction reflected by altered mentation, tachypnea, and hypotension, satisfying the modern definition of sepsis as life-threatening organ dysfunction due to a dysregulated host response. A simple lower urinary tract infection lacks systemic organ failure, and attributing the picture purely to delirium or dehydration would dangerously underestimate a life-threatening condition.
- A patient with septic shock is being resuscitated. Which initial intravenous fluid and approximate volume best reflects current recommendations for early resuscitation in sepsis-induced hypoperfusion?
- Hypotonic dextrose solution given slowly over 24 hours
- Balanced crystalloid, approximately 30 mL/kg, given early
- Routine large-volume colloid such as albumin as the first-line fluid
- Packed red blood cells regardless of hemoglobin
Correct answer: Balanced crystalloid, approximately 30 mL/kg, given early
Early administration of about 30 mL/kg of a balanced crystalloid is correct because guidelines recommend prompt crystalloid resuscitation for sepsis-induced hypoperfusion, with further fluids titrated to dynamic measures of response. Hypotonic dextrose does not effectively expand the intravascular space, colloids are not the routine first-line fluid, and transfusion is reserved for low hemoglobin rather than used as the initial resuscitation fluid.
- A clinician evaluates a patient with suspected sepsis and orders cultures before antibiotics. Which principle best balances the goals of diagnosis and timely treatment?
- Obtain blood cultures only after the patient has clinically improved
- Skip cultures entirely so antibiotics can start sooner
- Obtain blood cultures promptly but do not delay antibiotics beyond a brief window to collect them
- Wait for culture results before giving any antibiotic
Correct answer: Obtain blood cultures promptly but do not delay antibiotics beyond a brief window to collect them
Obtaining cultures promptly while not significantly delaying antibiotics is the correct principle because pre-antibiotic cultures improve pathogen identification, yet early antibiotics save lives, so cultures should be drawn quickly and therapy started without undue delay. Waiting for culture results, drawing cultures only after improvement, or skipping cultures altogether each sacrifices either timely treatment or diagnostic yield.
- A patient resuscitated for septic shock has a central venous catheter and arterial line. Which mean arterial pressure target is generally recommended as the initial goal during vasopressor support?
- At least 50 mmHg
- At least 110 mmHg
- At least 90 mmHg
- At least 65 mmHg
Correct answer: At least 65 mmHg
A mean arterial pressure of at least 65 mmHg is the generally recommended initial target because this level is associated with adequate organ perfusion in most patients with septic shock while avoiding the harms of excessive vasopressor use. A goal of 50 mmHg is too low to ensure perfusion, and routinely targeting 90 or 110 mmHg increases vasopressor exposure without proven benefit for typical patients.
- A 30-year-old returns from West Africa with fever and is found to have Plasmodium falciparum on smear with 1 percent parasitemia, normal mental status, and no organ dysfunction. Which treatment approach is appropriate for this uncomplicated falciparum malaria from a chloroquine-resistant region?
- Oral artemisinin-based combination therapy
- Oral chloroquine monotherapy
- Intravenous vancomycin
- Oral primaquine alone
Correct answer: Oral artemisinin-based combination therapy
Oral artemisinin-based combination therapy is appropriate because uncomplicated falciparum malaria acquired in a chloroquine-resistant region is treated with an effective oral artemisinin-based regimen. Chloroquine monotherapy fails against resistant falciparum, vancomycin is an antibacterial with no antimalarial activity, and primaquine alone is used to clear dormant liver stages of vivax and ovale, not to treat blood-stage falciparum infection.
- A clinician counsels a traveler about which Plasmodium species can cause a relapse months after the initial illness even when blood-stage treatment was adequate. Which species are responsible for true relapse?
- Plasmodium falciparum and Plasmodium malariae
- Plasmodium vivax and Plasmodium ovale
- Plasmodium falciparum only
- Plasmodium malariae only
Correct answer: Plasmodium vivax and Plasmodium ovale
Plasmodium vivax and Plasmodium ovale are responsible for true relapse because they form dormant liver-stage hypnozoites that can reactivate weeks to months later, which is why eradication of the liver stage is required to prevent recurrence. Plasmodium falciparum and Plasmodium malariae do not form hypnozoites; falciparum can recrudesce from inadequately treated blood-stage parasites, but that is not the same as hypnozoite-driven relapse.
- A pregnant traveler returns from a malaria-endemic area with confirmed uncomplicated malaria. The clinician notes that one common antimalarial must be avoided because it can trigger hemolysis and is contraindicated in pregnancy. Which test must be checked before that drug is used in nonpregnant relapse-prevention therapy?
- Thyroid-stimulating hormone before giving chloroquine
- Serum ferritin before giving artesunate
- Glucose-6-phosphate dehydrogenase activity before giving primaquine
- Prothrombin time before giving doxycycline
Correct answer: Glucose-6-phosphate dehydrogenase activity before giving primaquine
Glucose-6-phosphate dehydrogenase activity must be checked before primaquine because primaquine can precipitate severe oxidative hemolysis in deficient individuals, and it is also contraindicated in pregnancy. Ferritin, thyroid-stimulating hormone, and prothrombin time are not the relevant safety screens for the respective antimalarials listed, and only the G6PD-primaquine pairing reflects this critical pretreatment requirement.
- A clinician evaluates a febrile patient who returned from an endemic region two weeks ago, and an initial blood smear is negative for malaria. Which next step is most appropriate if clinical suspicion remains high?
- Conclude malaria is excluded after one negative smear
- Order a single antibody serology and discharge the patient
- Start empiric antibacterial therapy for presumed sepsis only
- Repeat blood smears every 12 to 24 hours over the next 2 to 3 days
Correct answer: Repeat blood smears every 12 to 24 hours over the next 2 to 3 days
Repeating blood smears every 12 to 24 hours over several days is correct because malaria parasitemia fluctuates and a single negative smear does not exclude the diagnosis; serial smears improve detection sensitivity. Declaring malaria excluded after one smear can be fatal, antibacterial therapy alone does not treat malaria, and antibody serology is not used to diagnose acute infection because it reflects past exposure.
- A 23-year-old presents with painful, grouped vesicles on an erythematous base on the genitalia accompanied by tender inguinal lymphadenopathy and dysuria during a first episode. Which sexually transmitted infection is most consistent with this presentation?
- Genital herpes simplex virus infection
- Primary syphilis
- Chancroid
- Granuloma inguinale
Correct answer: Genital herpes simplex virus infection
Genital herpes simplex virus infection is most consistent because a first episode classically produces clusters of painful vesicles that ulcerate, with regional tender lymphadenopathy and dysuria. Primary syphilis causes a single painless indurated chancre, chancroid causes a painful but ragged deep ulcer without grouped vesicles, and granuloma inguinale causes beefy-red painless ulcers, none of which match the painful grouped vesicular eruption seen here.
- A clinician explains to a household why an N95 respirator, rather than a standard surgical mask, is required when entering the room of a patient with active pulmonary tuberculosis. Which property of the pathogen best justifies this precaution?
- It spreads through large respiratory droplets that fall quickly
- It is transmitted by tiny droplet nuclei that remain suspended in air over distance
- It is spread primarily by direct skin contact
- It is transmitted through contaminated food and water
Correct answer: It is transmitted by tiny droplet nuclei that remain suspended in air over distance
Transmission by tiny airborne droplet nuclei is the correct justification because Mycobacterium tuberculosis is carried in particles small enough to stay suspended and travel through air, requiring a fitted N95 respirator and negative-pressure isolation rather than a surgical mask. Large-droplet spread that falls within a short distance characterizes pathogens managed with droplet precautions, and tuberculosis is not chiefly spread by skin contact or by food and water.
- A clinician compares the ulcers of two genital infections to refine the differential for syphilis. Which feature most reliably distinguishes the primary chancre of syphilis from a chancroid ulcer?
- The syphilitic chancre is painful while chancroid is painless
- Both ulcers are painful and indistinguishable on examination
- The syphilitic chancre is painless and indurated while chancroid is painful and soft
- The syphilitic chancre always has multiple lesions while chancroid is single
Correct answer: The syphilitic chancre is painless and indurated while chancroid is painful and soft
The painless, firm, indurated nature of the syphilitic chancre contrasted with the painful, soft, ragged chancroid ulcer is the most reliable distinguishing feature. This difference in pain and induration is a classic clinical clue. The reversed pain description is incorrect, the ulcers are not clinically identical, and lesion number is not a dependable discriminator since either can occasionally be solitary or multiple.
- A clinician reviews the natural staging of untreated syphilis with a learner. Which sequence correctly orders the stages over time?
- Secondary, then primary, then tertiary
- Tertiary, then secondary, then primary
- Latent, then primary, then secondary
- Primary, then secondary, then latent, then tertiary
Correct answer: Primary, then secondary, then latent, then tertiary
The correct sequence is primary (chancre), then secondary (disseminated rash and systemic findings), then latent (asymptomatic seroreactivity), and finally tertiary (gummas, cardiovascular, or neurologic disease) in a subset of untreated patients. The other orderings invert this natural history; the painless chancre always precedes the disseminated secondary stage, which is followed by latency before late complications develop.
- A 19-year-old with mononucleosis has marked fatigue and pharyngitis, and the clinician reviews the typical course. Which statement about the expected recovery is most accurate?
- Fatigue may persist for weeks, and full recovery often takes several weeks
- Fatigue characteristically resolves within 24 hours of diagnosis
- Symptoms require lifelong antiviral suppression
- The illness invariably progresses to chronic active infection
Correct answer: Fatigue may persist for weeks, and full recovery often takes several weeks
Persistent fatigue over weeks with gradual recovery is accurate because infectious mononucleosis is largely self-limited but the malaise and fatigue commonly linger for several weeks while the acute pharyngitis and adenopathy improve sooner. Symptoms do not vanish within a day, the illness does not require lifelong antiviral suppression, and progression to chronic active EBV infection is rare rather than invariable.
- A clinician suspects malaria in a febrile returning traveler and wants a rapid bedside aid while awaiting microscopy. Which test can quickly support the diagnosis by detecting parasite antigens?
- A potassium hydroxide preparation
- A heterophile antibody test
- A malaria rapid diagnostic antigen test
- A rapid streptococcal antigen test
Correct answer: A malaria rapid diagnostic antigen test
A malaria rapid diagnostic antigen test is correct because these point-of-care assays detect Plasmodium-specific antigens and can rapidly support the diagnosis while definitive microscopy is performed. A heterophile test screens for mononucleosis, a potassium hydroxide preparation evaluates for fungal elements, and a rapid streptococcal antigen test detects group A streptococcal pharyngitis, none of which identify malaria parasites.
- A clinician educates a patient about how Lyme disease, Rocky Mountain spotted fever, and other tick-borne illnesses are acquired. Which statement accurately reflects the route of transmission for these conditions?
- They are spread person-to-person through respiratory droplets
- They are sexually transmitted infections
- They are transmitted through contaminated drinking water
- They are acquired through the bite of an infected tick vector
Correct answer: They are acquired through the bite of an infected tick vector
Acquisition through the bite of an infected tick is accurate because Lyme disease (Ixodes ticks) and Rocky Mountain spotted fever (Dermacentor ticks) are vector-borne illnesses transmitted when an infected tick feeds. They are not spread person-to-person by respiratory droplets, are not waterborne, and are not sexually transmitted, which underscores why tick avoidance and prompt removal are the key prevention strategies.
- A traveler is counseled that, in addition to chemoprophylaxis, personal protective measures reduce malaria risk. Which measure most directly targets the Anopheles mosquito vector responsible for transmission?
- Boiling all drinking water before consumption
- Sleeping under insecticide-treated bed nets and using DEET-containing repellent
- Avoiding undercooked shellfish
- Wearing an N95 respirator outdoors
Correct answer: Sleeping under insecticide-treated bed nets and using DEET-containing repellent
Insecticide-treated bed nets and DEET-containing repellent most directly reduce malaria risk because Anopheles mosquitoes bite mainly at night, so barrier and repellent measures lower vector contact and complement chemoprophylaxis. Boiling water and avoiding shellfish prevent enteric infections, and an N95 respirator addresses airborne respiratory pathogens, none of which interrupt mosquito-borne transmission of Plasmodium.
- A 58-year-old man presents with the sudden onset of excruciating pain, redness, and swelling of the first metatarsophalangeal joint that woke him from sleep. Arthrocentesis of the joint is performed. Which finding on synovial fluid analysis under polarized light microscopy best confirms the diagnosis?
- Rhomboid-shaped crystals that are positively birefringent (blue when parallel to the compensator)
- Needle-shaped crystals that are negatively birefringent (yellow when parallel to the compensator)
- Gram-positive cocci in clusters with abundant neutrophils
- No crystals with a normal white blood cell count
Correct answer: Needle-shaped crystals that are negatively birefringent (yellow when parallel to the compensator)
Negatively birefringent, needle-shaped crystals confirm gout. Monosodium urate crystals appear yellow when aligned parallel to the axis of the red compensator and are needle-shaped, distinguishing gout from pseudogout, whose calcium pyrophosphate crystals are rhomboid and positively birefringent. Gram-positive cocci would suggest septic arthritis, and a normal fluid analysis would argue against crystal-induced arthritis.
- A 49-year-old man with a history of recurrent acute gout flares now has elevated serum uric acid and a tophus on his ear. He has had four flares in the past year. Which medication is most appropriate to lower his serum urate for long-term prevention?
- Colchicine alone
- Indomethacin alone
- Intra-articular triamcinolone
- Allopurinol
Correct answer: Allopurinol
Allopurinol is the preferred urate-lowering therapy for recurrent gout. As a xanthine oxidase inhibitor, it reduces uric acid production and is indicated for frequent flares, tophi, or urate nephrolithiasis. Colchicine and indomethacin treat or prevent acute attacks but do not lower urate stores, and intra-articular steroids manage an acute flare rather than prevent future ones.
- A 45-year-old woman reports several months of symmetric pain and swelling in the small joints of both hands and wrists, with morning stiffness lasting more than one hour. Examination shows synovitis of the metacarpophalangeal and proximal interphalangeal joints. Which serologic test is most specific for the suspected diagnosis?
- Anti-cyclic citrullinated peptide (anti-CCP) antibody
- Antinuclear antibody (ANA)
- Erythrocyte sedimentation rate (ESR)
- Serum uric acid
Correct answer: Anti-cyclic citrullinated peptide (anti-CCP) antibody
Anti-CCP antibody is the most specific test for rheumatoid arthritis. It carries high specificity and predicts more erosive disease, whereas rheumatoid factor is less specific. ANA is sensitive for lupus rather than rheumatoid arthritis, ESR is a nonspecific inflammatory marker, and uric acid relates to gout.
- A 52-year-old woman with rheumatoid arthritis is being started on long-term disease-modifying therapy. Which agent is considered the first-line disease-modifying antirheumatic drug (DMARD) for most patients?
- Prednisone
- Naproxen
- Methotrexate
- Hydroxychloroquine monotherapy
Correct answer: Methotrexate
Methotrexate is the anchor first-line DMARD for rheumatoid arthritis. It slows joint destruction and is the cornerstone of therapy, often combined with other agents when needed. Prednisone and naproxen relieve inflammation but do not modify long-term disease progression as effectively, and hydroxychloroquine alone is reserved for milder disease.
- Which radiographic finding is most characteristic of rheumatoid arthritis rather than osteoarthritis?
- Osteophyte formation at joint margins
- Periarticular osteopenia with marginal joint erosions
- Subchondral sclerosis with asymmetric joint-space narrowing
- Chondrocalcinosis of the menisci
Correct answer: Periarticular osteopenia with marginal joint erosions
Periarticular osteopenia with marginal erosions is characteristic of rheumatoid arthritis. The inflammatory pannus erodes bone at the joint margins and demineralizes adjacent bone. Osteophytes, subchondral sclerosis, and asymmetric narrowing are hallmarks of osteoarthritis, and chondrocalcinosis points to calcium pyrophosphate deposition disease.
- A 64-year-old woman complains of gradually worsening knee pain that is worse with activity and better with rest. Examination reveals bony enlargement of the distal interphalangeal joints. What are these nodular enlargements called?
- Bouchard nodes
- Heberden nodes
- Tophi
- Osler nodes
Correct answer: Heberden nodes
Heberden nodes are bony enlargements of the distal interphalangeal joints in osteoarthritis. Bouchard nodes occur at the proximal interphalangeal joints. Tophi are urate deposits seen in chronic gout, and Osler nodes are tender lesions of infective endocarditis.
- A 68-year-old man with knee osteoarthritis has pain inadequately controlled with acetaminophen and topical agents. He has no contraindications. Which oral medication class is the next recommended step for symptomatic relief?
- Oral glucocorticoids
- Opioid analgesics
- Nonsteroidal anti-inflammatory drugs (NSAIDs)
- Allopurinol
Correct answer: Nonsteroidal anti-inflammatory drugs (NSAIDs)
NSAIDs are the recommended next step when acetaminophen fails in osteoarthritis. They reduce both pain and inflammation. Systemic glucocorticoids are not used for routine osteoarthritis, opioids are reserved for refractory cases due to risk, and allopurinol treats gout, not osteoarthritis.
- Which feature best distinguishes the joint stiffness of osteoarthritis from that of rheumatoid arthritis?
- Morning stiffness lasting more than one hour that improves with use
- Symmetric small-joint swelling with systemic fatigue
- Migratory polyarthritis following a sore throat
- Morning stiffness lasting less than 30 minutes that worsens with use through the day
Correct answer: Morning stiffness lasting less than 30 minutes that worsens with use through the day
Brief morning stiffness under 30 minutes that worsens with activity is typical of osteoarthritis. The degenerative process produces mechanical pain that increases with joint use. Prolonged morning stiffness improving with use suggests rheumatoid arthritis, symmetric swelling with fatigue is inflammatory, and migratory arthritis after pharyngitis suggests rheumatic fever.
- A 42-year-old administrative assistant reports numbness and tingling in the thumb, index, and middle fingers, worse at night. Tapping over the volar wrist reproduces the paresthesias. Compression of which nerve explains these findings?
- Median nerve
- Ulnar nerve
- Radial nerve
- Axillary nerve
Correct answer: Median nerve
Compression of the median nerve at the wrist causes carpal tunnel syndrome. The median nerve supplies sensation to the thumb, index, middle, and radial half of the ring finger, and a positive Tinel sign reproduces the symptoms. The ulnar nerve supplies the fifth digit, the radial nerve the dorsal hand, and the axillary nerve the deltoid region.
- During evaluation for carpal tunnel syndrome, the clinician asks the patient to hold the wrists in forced flexion with the dorsal surfaces pressed together for 60 seconds, reproducing the paresthesias. What is the name of this provocative maneuver?
- Lachman test
- Drop-arm test
- Finkelstein test
- Phalen test
Correct answer: Phalen test
The Phalen test reproduces median nerve symptoms with sustained wrist flexion in carpal tunnel syndrome. The Lachman test assesses the anterior cruciate ligament, the drop-arm test evaluates the rotator cuff, and the Finkelstein test diagnoses de Quervain tenosynovitis.
- A 38-year-old pregnant woman is diagnosed with mild carpal tunnel syndrome without thenar atrophy. Which initial management is most appropriate?
- Immediate surgical carpal tunnel release
- Long-term oral corticosteroids
- Wrist arthrodesis
- Nocturnal wrist splinting in a neutral position
Correct answer: Nocturnal wrist splinting in a neutral position
Neutral-position nocturnal wrist splinting is the appropriate first-line treatment for mild carpal tunnel syndrome. It keeps the wrist out of flexion or extension to reduce nerve compression and is especially preferred in pregnancy, where symptoms often resolve after delivery. Surgery is reserved for severe or refractory cases with motor deficits, and long-term steroids and arthrodesis are not initial measures.
- A 60-year-old man reports difficulty lifting his arm overhead after months of shoulder pain. On examination, when his arm is passively raised to 90 degrees of abduction and he is asked to slowly lower it, the arm suddenly drops. Which structure is most likely injured?
- Supraspinatus tendon
- Anterior cruciate ligament
- Median nerve
- Achilles tendon
Correct answer: Supraspinatus tendon
A positive drop-arm test indicates a rotator cuff (supraspinatus) tear. The supraspinatus is the most commonly torn rotator cuff tendon and the inability to control lowering the abducted arm reflects its dysfunction. The anterior cruciate ligament and Achilles tendon are in the lower extremity, and the median nerve relates to carpal tunnel syndrome.
- Which imaging study is most useful for confirming a suspected full-thickness rotator cuff tear when surgical planning is being considered?
- Plain anteroposterior radiograph
- Bone scan
- Electromyography
- Magnetic resonance imaging (MRI)
Correct answer: Magnetic resonance imaging (MRI)
MRI best visualizes a rotator cuff tear and guides surgical planning. It depicts soft-tissue tendon integrity and the extent of tearing. Plain radiographs assess bony abnormalities but not the tendon directly, bone scans evaluate metabolic bone activity, and electromyography assesses nerve and muscle electrical function.
- A 24-year-old soccer player plants her foot, twists her knee, and hears a loud pop followed by immediate swelling and instability. The clinician stabilizes the femur and pulls the tibia forward with the knee flexed to 30 degrees, noting increased anterior translation. Which test was performed and which ligament does it assess?
- McMurray test assessing the meniscus
- Posterior drawer test assessing the posterior cruciate ligament
- Lachman test assessing the anterior cruciate ligament
- Valgus stress test assessing the medial collateral ligament
Correct answer: Lachman test assessing the anterior cruciate ligament
The Lachman test assesses the anterior cruciate ligament, and increased anterior tibial translation with a soft endpoint indicates a tear. The McMurray test evaluates meniscal tears, the posterior drawer assesses the posterior cruciate ligament, and the valgus stress test checks the medial collateral ligament.
- A 19-year-old basketball player sustains a noncontact pivoting injury with an audible pop, rapid hemarthrosis, and knee instability. After confirming the diagnosis with examination and MRI, which intervention is most appropriate for this young, highly active patient?
- Lifelong knee immobilization in a cast
- Long-term oral corticosteroids
- Joint fusion (arthrodesis)
- Arthroscopic ligament reconstruction
Correct answer: Arthroscopic ligament reconstruction
Arthroscopic reconstruction is the preferred treatment for an anterior cruciate ligament tear in a young, active patient. It restores knee stability and allows return to pivoting sports. Prolonged casting, corticosteroids, and arthrodesis are not appropriate management of an isolated ligament tear.
- A 27-year-old man with a HLA-B27 association reports several months of low back pain and stiffness that is worse in the morning and improves with exercise. Examination shows reduced lumbar flexion and limited chest expansion. Which radiographic finding supports the diagnosis?
- Marginal erosions of the metacarpophalangeal joints
- Sacroiliitis with fusion of the sacroiliac joints
- Punched-out lytic lesions of the skull
- Chondrocalcinosis of the knee menisci
Correct answer: Sacroiliitis with fusion of the sacroiliac joints
Sacroiliitis is the earliest and most characteristic radiographic finding in ankylosing spondylitis. Inflammation of the axial skeleton begins at the sacroiliac joints and can progress to a fused bamboo spine. Metacarpophalangeal erosions suggest rheumatoid arthritis, punched-out skull lesions multiple myeloma, and chondrocalcinosis pseudogout.
- A 30-year-old man with ankylosing spondylitis has persistent inflammatory back pain and morning stiffness despite a structured exercise program. Which medication class is recommended as initial pharmacologic therapy?
- Nonsteroidal anti-inflammatory drugs (NSAIDs)
- Methotrexate
- Allopurinol
- Oral bisphosphonates
Correct answer: Nonsteroidal anti-inflammatory drugs (NSAIDs)
NSAIDs combined with exercise are first-line therapy for ankylosing spondylitis. They reduce inflammatory back pain and stiffness in the axial skeleton. Methotrexate is ineffective for axial disease, allopurinol treats gout, and bisphosphonates address osteoporosis rather than the inflammatory process.
- A late finding in advanced ankylosing spondylitis is a rigid spine on radiograph caused by syndesmophytes bridging adjacent vertebrae. What is this radiographic appearance commonly called?
- Boot-shaped heart
- Bamboo spine
- Bamboo nodule
- Honeycomb lung
Correct answer: Bamboo spine
The bamboo spine appearance results from vertical syndesmophytes fusing the vertebral bodies in ankylosing spondylitis. This produces a rigid, immobile spine. A boot-shaped heart is seen in tetralogy of Fallot, and honeycombing describes advanced pulmonary fibrosis.
- A 56-year-old man with poorly controlled diabetes presents with a chronic, draining foot ulcer overlying the metatarsal. He has localized bone tenderness and a probe reaches bone through the wound. Which imaging study is most sensitive for confirming the suspected bone infection?
- Plain radiograph alone
- Ankle-brachial index
- Magnetic resonance imaging (MRI)
- Duplex ultrasound
Correct answer: Magnetic resonance imaging (MRI)
MRI is the most sensitive imaging study for osteomyelitis. It detects early marrow edema and bony involvement before changes appear on plain films, which may lag by one to two weeks. The ankle-brachial index assesses arterial perfusion, and duplex ultrasound evaluates vascular flow, neither of which diagnoses bone infection.
- In a healthy adult who develops hematogenous osteomyelitis without prosthetic hardware, which organism is the most common causative pathogen?
- Salmonella species
- Pseudomonas aeruginosa
- Pasteurella multocida
- Staphylococcus aureus
Correct answer: Staphylococcus aureus
Staphylococcus aureus is the most common cause of osteomyelitis overall. It accounts for the majority of hematogenous and contiguous-spread bone infections. Salmonella is characteristically associated with sickle cell disease, Pseudomonas with puncture wounds through footwear or IV drug use, and Pasteurella with animal bites.
- A 7-year-old child with sickle cell disease develops fever and focal bone pain and is diagnosed with osteomyelitis. Compared with the general population, which organism has a notably increased likelihood as the cause in this patient?
- Borrelia burgdorferi
- Streptococcus pneumoniae
- Salmonella species
- Escherichia coli
Correct answer: Salmonella species
Salmonella is a characteristic cause of osteomyelitis in sickle cell disease. Functional asplenia and bony microinfarcts increase susceptibility to Salmonella seeding of bone, although Staphylococcus aureus remains common. Borrelia causes Lyme disease, and the other organisms are not classically linked to osteomyelitis in this population.
- A 22-year-old man sustains a closed tibial shaft fracture. Six hours later he reports severe, deep calf pain that is out of proportion to the injury and markedly worsened by passive stretching of the toes. The compartment is tense and tender. What is the most appropriate immediate management?
- Emergent fasciotomy
- Application of a tight circumferential cast
- Oral NSAIDs and reassurance
- Elevation of the limb above heart level only
Correct answer: Emergent fasciotomy
Emergent fasciotomy is the definitive treatment for acute compartment syndrome. Pain out of proportion and pain with passive stretch signal critically elevated compartment pressure that threatens tissue viability, and surgical decompression must not be delayed. A tight cast would worsen pressure, NSAIDs are inadequate, and the limb should be kept at heart level rather than elevated to preserve perfusion.
- Which of the following is the earliest and most reliable clinical sign of acute compartment syndrome?
- Pain out of proportion to the injury, especially with passive stretch
- Pulselessness of the distal extremity
- Pallor of the overlying skin
- Paralysis of the affected muscle group
Correct answer: Pain out of proportion to the injury, especially with passive stretch
Pain out of proportion, worsened by passive stretch, is the earliest sign of compartment syndrome. The other findings, often summarized as the late P's of pallor, pulselessness, paresthesia, and paralysis, appear later when ischemic damage may already be irreversible. Relying on pulselessness risks dangerous delay.
- A 5-year-old presents 36 hours after a minor fall with refusal to bear weight, fever, and a warm, swollen, exquisitely tender knee held in slight flexion. Arthrocentesis yields cloudy fluid with a white cell count of 75,000/microliter, predominantly neutrophils. What is the most appropriate next step?
- Outpatient oral NSAIDs and follow-up in one week
- Joint drainage plus prompt empiric intravenous antibiotics
- Intra-articular corticosteroid injection
- Reassurance and activity restriction only
Correct answer: Joint drainage plus prompt empiric intravenous antibiotics
Septic arthritis requires urgent joint drainage and empiric intravenous antibiotics. A markedly elevated synovial neutrophil count in a hot, swollen joint indicates bacterial infection that can destroy cartilage within hours. NSAIDs, intra-articular steroids, and observation would dangerously delay treatment of a joint emergency.
- A 28-year-old sexually active woman presents with migratory polyarthralgia, tenosynovitis of the wrists, and scattered pustular skin lesions, followed by a hot, swollen knee. Which organism is the most likely cause of her arthritis?
- Neisseria gonorrhoeae
- Staphylococcus aureus
- Borrelia burgdorferi
- Mycobacterium tuberculosis
Correct answer: Neisseria gonorrhoeae
Neisseria gonorrhoeae is the most likely cause of septic arthritis in a young, sexually active adult. Disseminated gonococcal infection produces the classic triad of migratory polyarthralgia, tenosynovitis, and pustular dermatitis. Staphylococcus aureus is the most common nongonococcal cause, while Borrelia and tuberculosis cause distinct clinical pictures.
- A 14-year-old obese boy presents with several weeks of a painful limp and is found to hold the affected hip in external rotation, with limited internal rotation. A frog-leg lateral radiograph shows posterior and inferior displacement of the femoral head epiphysis. What is the most likely diagnosis?
- Developmental dysplasia of the hip
- Legg-Calve-Perthes disease
- Slipped capital femoral epiphysis
- Transient synovitis of the hip
Correct answer: Slipped capital femoral epiphysis
Slipped capital femoral epiphysis classically affects obese adolescents and shows displacement of the femoral head through the growth plate. The hip rests in external rotation with limited internal rotation. Legg-Calve-Perthes disease is avascular necrosis in younger children, developmental dysplasia presents in infancy, and transient synovitis is a self-limited postviral process.
- A 13-year-old competitive runner reports anterior knee pain and a tender, swollen prominence over the tibial tubercle that worsens with squatting and jumping. What is the most likely diagnosis?
- Patellar dislocation
- Anterior cruciate ligament tear
- Septic arthritis of the knee
- Osgood-Schlatter disease
Correct answer: Osgood-Schlatter disease
Osgood-Schlatter disease is traction apophysitis of the tibial tubercle in active adolescents. Repetitive quadriceps pull on the immature tubercle produces localized pain and swelling. It lacks the joint effusion of septic arthritis, the instability of a ligament tear, and the acute displacement of a patellar dislocation.
- A 50-year-old man wakes with severe pain, redness, and swelling of the knee. Arthrocentesis reveals rhomboid-shaped, weakly positively birefringent crystals, and a radiograph shows linear calcification within the joint cartilage. What is the most likely diagnosis?
- Pseudogout (calcium pyrophosphate deposition disease)
- Gout
- Septic arthritis
- Rheumatoid arthritis
Correct answer: Pseudogout (calcium pyrophosphate deposition disease)
Rhomboid, positively birefringent crystals with chondrocalcinosis indicate pseudogout. Calcium pyrophosphate crystals deposit in cartilage and most often involve the knee or wrist. Gout produces needle-shaped negatively birefringent crystals, septic arthritis shows organisms and high neutrophil counts, and rheumatoid arthritis is noncrystalline.
- A 30-year-old recreational basketball player feels a sudden snap in the back of the ankle while pushing off and is unable to push off the foot. Squeezing the calf fails to produce plantar flexion of the foot. Which injury does this positive test indicate?
- Achilles tendon rupture
- Plantar fasciitis
- Lateral ankle sprain
- Tarsal tunnel syndrome
Correct answer: Achilles tendon rupture
A positive Thompson test, with absent plantar flexion on calf squeeze, indicates an Achilles tendon rupture. The intact tendon normally transmits calf compression to plantarflex the foot. Plantar fasciitis causes heel pain, an ankle sprain involves ligaments, and tarsal tunnel syndrome is a nerve entrapment.
- A 45-year-old runner reports sharp heel pain that is worst with the first few steps in the morning and improves after walking. Examination reveals tenderness at the medial calcaneal tuberosity. What is the most likely diagnosis?
- Achilles tendinopathy
- Tarsal tunnel syndrome
- Morton neuroma
- Plantar fasciitis
Correct answer: Plantar fasciitis
Plantar fasciitis causes inferior heel pain that is worst with the first morning steps. Tenderness localizes to the medial calcaneal tuberosity where the plantar fascia originates. Achilles tendinopathy causes posterior heel pain, tarsal tunnel syndrome causes burning paresthesias, and Morton neuroma produces forefoot pain between the toes.
- A 35-year-old man inverts his ankle stepping off a curb and develops swelling and tenderness over the anterolateral ankle, with the ability to bear weight for several steps and no bony tenderness over the malleoli. Which structure is most commonly injured in this type of sprain?
- Anterior talofibular ligament
- Deltoid ligament
- Anterior cruciate ligament
- Calcaneofibular insertion of the Achilles tendon
Correct answer: Anterior talofibular ligament
The anterior talofibular ligament is the most commonly injured structure in an inversion ankle sprain. It is the weakest of the lateral ligaments and fails first with inversion. The deltoid ligament is medial and resists eversion, the anterior cruciate ligament is in the knee, and the Achilles tendon is not a ligament.
- A 25-year-old man falls onto an outstretched hand and has tenderness in the anatomic snuffbox. Initial wrist radiographs are unremarkable. What is the most appropriate management?
- Discharge with reassurance and no follow-up
- Immediate open reduction and internal fixation
- Thumb spica splinting with repeat imaging in 10 to 14 days
- Range-of-motion exercises and ice only
Correct answer: Thumb spica splinting with repeat imaging in 10 to 14 days
Snuffbox tenderness after a fall warrants thumb spica immobilization even with normal initial films, because scaphoid fractures are often radiographically occult early. The scaphoid has a tenuous retrograde blood supply, and a missed fracture risks avascular necrosis and nonunion. Repeat imaging or advanced imaging confirms the fracture once it becomes visible.
- A 70-year-old woman falls onto an outstretched hand and presents with a dorsally angulated, dinner-fork deformity of the distal forearm. Which fracture is most likely?
- Boxer fracture of the fifth metacarpal
- Colles fracture of the distal radius
- Jones fracture of the fifth metatarsal
- Galeazzi fracture of the radial shaft
Correct answer: Colles fracture of the distal radius
A Colles fracture is a distal radius fracture with dorsal angulation producing the dinner-fork deformity, classically from a fall on an outstretched hand in older patients with osteoporosis. A boxer fracture involves the fifth metacarpal neck, a Jones fracture the fifth metatarsal base, and a Galeazzi fracture the radial shaft with distal radioulnar joint disruption.
- A 19-year-old man fractures the surgical neck of the humerus and is noted to have weakness of shoulder abduction and a patch of numbness over the lateral deltoid. Injury to which nerve best explains these findings?
- Median nerve
- Ulnar nerve
- Axillary nerve
- Long thoracic nerve
Correct answer: Axillary nerve
The axillary nerve is most at risk with surgical neck humerus fractures, producing deltoid weakness and lateral shoulder numbness. It wraps around the surgical neck of the humerus. The median and ulnar nerves are more distal, and the long thoracic nerve injury causes scapular winging.
- A 65-year-old woman is found to have a low-trauma vertebral compression fracture, and bone density testing reveals a T-score of -2.7. Which medication class is first-line to reduce future fracture risk?
- Systemic corticosteroids
- Bisphosphonates
- Loop diuretics
- Allopurinol
Correct answer: Bisphosphonates
Bisphosphonates are first-line pharmacologic therapy for osteoporosis to reduce fracture risk. They inhibit osteoclast-mediated bone resorption. Corticosteroids actually cause bone loss, loop diuretics increase calcium excretion, and allopurinol treats gout.
- A 16-year-old girl is found on school screening to have a right thoracic curve with rib prominence on forward bending and no neurologic deficits. The Cobb angle is measured at 22 degrees. What is the most appropriate management?
- Immediate spinal fusion surgery
- Long-term opioid analgesia
- Observation with serial radiographs
- Lumbar puncture
Correct answer: Observation with serial radiographs
Mild adolescent idiopathic scoliosis with a Cobb angle under about 25 degrees is managed with observation and serial radiographs. Bracing is generally added for moderate curves around 25 to 40 degrees in a skeletally immature patient, and surgery is reserved for severe or progressive curves. Opioids and lumbar puncture have no role.
- A 42-year-old woman reports deep, aching pain at the lateral elbow that worsens with gripping and resisted wrist extension. There is point tenderness just distal to the lateral epicondyle. What is the most likely diagnosis?
- Medial epicondylitis
- Olecranon bursitis
- Cubital tunnel syndrome
- Lateral epicondylitis
Correct answer: Lateral epicondylitis
Lateral epicondylitis, or tennis elbow, causes lateral elbow pain reproduced by resisted wrist extension and gripping. It reflects overuse of the common extensor origin. Medial epicondylitis affects the flexor origin and medial elbow, olecranon bursitis causes a swollen posterior elbow, and cubital tunnel syndrome produces ulnar paresthesias.
- A 33-year-old woman reports pain at the radial side of the wrist when lifting her infant. Pain is reproduced when she tucks her thumb into a fist and the examiner deviates the wrist toward the ulnar side. What is the most likely diagnosis?
- Carpal tunnel syndrome
- De Quervain tenosynovitis
- Scaphoid fracture
- Rheumatoid arthritis
Correct answer: De Quervain tenosynovitis
A positive Finkelstein test indicates de Quervain tenosynovitis, an inflammation of the abductor pollicis longus and extensor pollicis brevis tendons. The maneuver stretches the inflamed tendons over the radial styloid. Carpal tunnel syndrome involves median nerve paresthesias, a scaphoid fracture follows acute trauma, and rheumatoid arthritis is a symmetric polyarthritis.
- A 47-year-old man with diabetes presents with progressive inability to fully extend the ring and little fingers, with a palpable cord and puckering of the palmar skin. Which condition does this describe?
- Trigger finger
- Dupuytren contracture
- Mallet finger
- Boutonniere deformity
Correct answer: Dupuytren contracture
Dupuytren contracture is a progressive fibrosis of the palmar fascia producing flexion contractures of the ring and little fingers with a palpable cord. It is associated with diabetes and northern European ancestry. Trigger finger causes catching with flexion, mallet finger is a dropped fingertip from extensor disruption, and boutonniere deformity affects the proximal interphalangeal joint.
- A 50-year-old man reports painful locking of his right middle finger that catches in a flexed position and then snaps straight, sometimes requiring passive extension. A tender nodule is palpable over the A1 pulley at the metacarpal head. What is the most likely diagnosis?
- Dupuytren contracture
- Mallet finger
- Trigger finger (stenosing tenosynovitis)
- Gamekeeper thumb
Correct answer: Trigger finger (stenosing tenosynovitis)
Trigger finger is stenosing tenosynovitis of the flexor tendon at the A1 pulley, causing catching and a snapping release of the digit. A palpable nodule at the pulley is characteristic. Dupuytren contracture produces a fixed contracture, mallet finger a dropped fingertip, and gamekeeper thumb a torn ulnar collateral ligament.
- A 55-year-old diabetic woman has 6 months of progressive shoulder stiffness and pain, with marked loss of both active and passive range of motion in all planes. Radiographs are normal. What is the most likely diagnosis?
- Rotator cuff tear
- Glenohumeral osteoarthritis
- Adhesive capsulitis (frozen shoulder)
- Acromioclavicular separation
Correct answer: Adhesive capsulitis (frozen shoulder)
Adhesive capsulitis, or frozen shoulder, causes global loss of both active and passive range of motion with normal radiographs, and is associated with diabetes. A rotator cuff tear typically preserves passive motion, osteoarthritis shows radiographic joint changes, and an acromioclavicular separation follows acute trauma.
- A 40-year-old warehouse worker develops acute low back pain after lifting a heavy box, with pain radiating down the posterior leg below the knee. Straight-leg raise on the affected side reproduces the radicular pain at 40 degrees. There are no bowel or bladder symptoms. What is the most appropriate initial management?
- Continued activity as tolerated with NSAIDs
- Immediate lumbar surgery
- Strict bed rest for two weeks
- Emergent MRI and surgical decompression
Correct answer: Continued activity as tolerated with NSAIDs
Acute lumbar radiculopathy from a herniated disc without red-flag features is managed conservatively with continued activity and NSAIDs. Most cases improve within weeks, and prolonged bed rest delays recovery. Surgery and emergent imaging are reserved for progressive neurologic deficits or cauda equina signs.
- A 68-year-old man reports bilateral leg pain and heaviness that develops with walking and is relieved by sitting or leaning forward over a shopping cart. Pulses are normal. What is the most likely diagnosis?
- Peripheral artery disease
- Anterior cruciate ligament tear
- Lumbar spinal stenosis
- Hip osteoarthritis
Correct answer: Lumbar spinal stenosis
Neurogenic claudication from lumbar spinal stenosis is relieved by forward flexion such as leaning over a cart, which widens the spinal canal. Normal pulses argue against vascular claudication of peripheral artery disease. An ACL tear follows acute knee trauma, and hip osteoarthritis causes groin pain with motion.
- A 25-year-old man sustains a forceful inversion ankle injury, and examination reveals tenderness at the base of the fifth metatarsal. Radiographs confirm a transverse fracture at the metaphyseal-diaphyseal junction of the fifth metatarsal. What is the eponym for this fracture, known for a high risk of nonunion?
- Boxer fracture
- Colles fracture
- Smith fracture
- Jones fracture
Correct answer: Jones fracture
A Jones fracture is a transverse fracture at the metaphyseal-diaphyseal junction of the fifth metatarsal and is prone to nonunion due to a poor blood supply in that watershed zone. A boxer fracture involves the fifth metacarpal, and Colles and Smith fractures involve the distal radius.
- A 9-year-old boy presents with a painless limp and hip and knee pain over several weeks, with limited internal rotation and abduction of the hip. Radiographs show flattening and fragmentation of the femoral head. What is the most likely diagnosis?
- Slipped capital femoral epiphysis
- Legg-Calve-Perthes disease
- Septic arthritis of the hip
- Osgood-Schlatter disease
Correct answer: Legg-Calve-Perthes disease
Legg-Calve-Perthes disease is idiopathic avascular necrosis of the femoral head in children, typically ages 4 to 8, producing femoral head flattening and fragmentation. Slipped capital femoral epiphysis affects older, obese adolescents, septic arthritis presents acutely with fever, and Osgood-Schlatter disease involves the tibial tubercle.
- A 23-year-old man reports knee pain and the sensation that his knee locks and catches after twisting it during soccer. The examiner flexes the knee, applies rotation, and extends it, eliciting a painful click along the joint line. Which structure is most likely injured?
- Anterior cruciate ligament
- Meniscus
- Patellar tendon
- Iliotibial band
Correct answer: Meniscus
A positive McMurray test with a painful joint-line click indicates a meniscal tear, which produces mechanical locking and catching. The maneuver traps the torn cartilage between the femur and tibia. The anterior cruciate ligament is tested by the Lachman test, while patellar tendon and iliotibial band problems cause anterior and lateral pain without true locking.
- A 45-year-old man develops a swollen, fluctuant, non-tender mass directly over the tip of the elbow after leaning on hard surfaces at work. Range of motion of the elbow joint is preserved. What is the most likely diagnosis?
- Septic arthritis of the elbow
- Gouty tophus of the joint
- Distal humerus fracture
- Olecranon bursitis
Correct answer: Olecranon bursitis
Olecranon bursitis presents as a swelling over the posterior elbow with preserved joint motion, often from repetitive pressure or trauma. Because the inflamed bursa lies outside the joint, flexion and extension remain intact. Septic arthritis and a fracture would limit motion, and a tophus reflects chronic gout deposits rather than an isolated bursal swelling.
- A 16-year-old soccer player feels his kneecap shift laterally and give way after a twisting movement, with the knee then buckling. He is apprehensive when the examiner pushes the patella laterally with the knee slightly flexed. Which condition does this positive apprehension test suggest?
- Patellar dislocation/instability
- Anterior cruciate ligament tear
- Meniscal tear
- Tibial plateau fracture
Correct answer: Patellar dislocation/instability
A positive patellar apprehension test indicates patellar instability or prior dislocation, as the patient guards against the patella displacing laterally. The patella most commonly dislocates laterally. An ACL tear is assessed by the Lachman test, a meniscal tear by the McMurray test, and a tibial plateau fracture follows higher-energy axial loading.
- A 68-year-old man arrives 90 minutes after the abrupt onset of left-sided weakness and facial droop. A noncontrast head CT shows no hemorrhage, his blood glucose is normal, and he meets all eligibility criteria. Which intervention offers the greatest benefit when delivered within this time window?
- Intravenous tissue plasminogen activator
- Oral aspirin alone
- Therapeutic-dose subcutaneous enoxaparin
- Permissive blood pressure lowering to normal range
Correct answer: Intravenous tissue plasminogen activator
Intravenous tissue plasminogen activator is the greatest-benefit therapy for an eligible acute ischemic stroke within the thrombolysis window. After hemorrhage is excluded and criteria are met, timely thrombolysis improves functional outcomes, and benefit declines with delay. Aspirin alone is less effective acutely, full anticoagulation is not indicated for acute ischemic stroke, and aggressive blood pressure lowering can worsen cerebral perfusion.
- A 72-year-old woman develops sudden inability to speak fluently, producing only effortful, halting words, though she clearly understands commands and is frustrated by her deficit. Which arterial territory is most likely involved?
- Posterior cerebral artery
- Anterior spinal artery
- Left middle cerebral artery, superior division
- Right middle cerebral artery, inferior division
Correct answer: Left middle cerebral artery, superior division
Nonfluent speech with preserved comprehension points to Broca aphasia from a left middle cerebral artery superior division infarct. This region supplies the dominant frontal language area, so effortful output with intact understanding and awareness of the deficit is typical. The posterior cerebral artery causes visual loss, the anterior spinal artery affects the cord, and the nondominant inferior division produces neglect rather than aphasia.
- A 64-year-old man with an acute ischemic stroke is found to have a clot in the proximal middle cerebral artery on CT angiography, presenting 4 hours after symptom onset with a large salvageable penumbra on perfusion imaging. Which additional treatment is most appropriate to restore blood flow to the affected territory?
- Hyperbaric oxygen therapy
- Immediate carotid endarterectomy
- Endovascular mechanical thrombectomy
- Decompressive craniectomy
Correct answer: Endovascular mechanical thrombectomy
Mechanical thrombectomy is appropriate for a large-vessel occlusion with salvageable tissue in an extended window. Endovascular clot retrieval restores perfusion to the penumbra and improves outcomes when a proximal occlusion and viable tissue are demonstrated. Craniectomy treats malignant edema later, carotid endarterectomy is a secondary-prevention procedure, and hyperbaric oxygen is not standard acute stroke care.
- A 75-year-old man recovering from an embolic ischemic stroke is found to have an irregularly irregular pulse, and an electrocardiogram confirms atrial fibrillation with no valvular disease. Which strategy is most appropriate for secondary stroke prevention given this source?
- Intravenous thrombolysis monthly
- Aspirin plus clopidogrel indefinitely
- No antithrombotic therapy
- Long-term oral anticoagulation
Correct answer: Long-term oral anticoagulation
Long-term oral anticoagulation is the best secondary prevention when atrial fibrillation is the embolic source. Anticoagulation reduces recurrent cardioembolic stroke more effectively than antiplatelet therapy in this setting. Dual antiplatelet therapy is not the standard for cardioembolic prevention, withholding therapy leaves high recurrence risk, and thrombolysis is an acute treatment, not prophylaxis.
- A 58-year-old man presents with sudden right-sided weakness, and rapid bedside assessment notes facial drooping, arm drift, and slurred speech with a known time of onset. This rapid screening mnemonic emphasizing face, arm, speech, and time is best used for which purpose?
- Quantifying intracranial pressure
- Grading severity of subarachnoid hemorrhage
- Recognizing stroke quickly to expedite emergency evaluation
- Diagnosing the underlying seizure type
Correct answer: Recognizing stroke quickly to expedite emergency evaluation
The face, arm, speech, time approach is used to rapidly recognize stroke and prompt urgent care. Identifying facial droop, arm weakness, and speech difficulty with attention to symptom onset shortens the path to time-sensitive therapy. It does not measure intracranial pressure, grade aneurysmal bleeds, or classify seizures.
- A 30-year-old woman awakens with acute right facial weakness involving the forehead, inability to fully close the right eye, and drooping of the corner of her mouth, with normal limb strength and sensation. Which examination feature most strongly favors a peripheral facial nerve palsy over a central cause?
- Sparing of the forehead muscles
- A homonymous visual field defect
- Associated contralateral arm weakness
- Inability to wrinkle the forehead on the affected side
Correct answer: Inability to wrinkle the forehead on the affected side
Forehead involvement with inability to wrinkle that side indicates a peripheral seventh nerve palsy such as Bell palsy. The forehead receives bilateral cortical input, so a central lesion spares it, whereas a peripheral lesion weakens the entire half of the face including the forehead. Contralateral arm weakness and a visual field cut suggest a central process, and forehead sparing is the central pattern.
- A 35-year-old man is diagnosed with Bell palsy and counseled on eye protection. Why is protecting the eye on the affected side a priority in this condition?
- Intraocular pressure rises acutely
- The pupil becomes fixed and dilated
- The optic nerve is directly inflamed
- Incomplete eyelid closure predisposes to corneal drying and abrasion
Correct answer: Incomplete eyelid closure predisposes to corneal drying and abrasion
Eye protection matters in Bell palsy because weak orbicularis oculi causes incomplete lid closure, drying the cornea. Lubricating drops, ointment, and taping the lid prevent exposure keratopathy and corneal abrasion. The condition does not raise intraocular pressure, fix the pupil, or inflame the optic nerve.
- A 48-year-old woman presents within 2 days of new complete unilateral facial droop diagnosed as idiopathic Bell palsy. Which therapy initiated early is most likely to improve her chance of full recovery?
- Oral corticosteroids
- Intravenous mannitol
- Botulinum toxin injection
- Long-term anticonvulsant therapy
Correct answer: Oral corticosteroids
Early oral corticosteroids improve recovery in idiopathic Bell palsy. Started within the first days, they reduce nerve inflammation and increase the likelihood of complete functional return. Mannitol, botulinum toxin, and anticonvulsants do not treat the acute facial nerve inflammation of Bell palsy.
- A 67-year-old man with Parkinson disease has motor symptoms that progressively limit his activities, and his clinician recommends the most effective medication for symptom control. Which agent provides the greatest symptomatic benefit by replenishing brain dopamine?
- Propranolol
- Carbidopa-levodopa
- Donepezil
- Gabapentin
Correct answer: Carbidopa-levodopa
Carbidopa-levodopa provides the greatest symptomatic benefit in Parkinson disease. Levodopa is converted to dopamine in the brain while carbidopa limits peripheral conversion, improving tremor, rigidity, and bradykinesia. Propranolol treats essential tremor, donepezil treats Alzheimer dementia, and gabapentin treats neuropathic pain.
- A 62-year-old woman with early Parkinson disease describes that her hand tremor is most noticeable when her hand rests in her lap and diminishes when she reaches for an object. Which term best describes this characteristic tremor?
- Resting tremor
- Intention tremor
- Postural tremor
- Physiologic tremor
Correct answer: Resting tremor
A tremor that is prominent at rest and lessens with voluntary movement is a resting tremor, the classic Parkinson tremor. It is often a pill-rolling motion of the hand that decreases with purposeful action. An intention tremor worsens approaching a target and is cerebellar, a postural tremor appears with sustained posture, and physiologic tremor is fine and low-amplitude.
- A 70-year-old man with advancing Parkinson disease develops sudden, brief episodes during walking in which his feet feel glued to the floor, especially at doorways, increasing his fall risk. This gait phenomenon is best described as which finding?
- Festinating gait
- Freezing of gait
- Steppage gait
- Antalgic gait
Correct answer: Freezing of gait
The transient inability to initiate or continue stepping, often at doorways, is freezing of gait in Parkinson disease. It contributes substantially to falls in advanced disease. Festination is involuntary hastening of small steps, steppage gait results from foot drop, and an antalgic gait is a pain-avoidance limp.
- A 28-year-old woman with relapsing-remitting multiple sclerosis presents with an acute, severe relapse causing disabling leg weakness. Which treatment is most appropriate to hasten recovery from this acute exacerbation?
- Plasmapheresis as first-line for every relapse
- Daily oral baclofen alone
- Interferon beta as monotherapy for the acute attack
- High-dose intravenous corticosteroids
Correct answer: High-dose intravenous corticosteroids
High-dose intravenous corticosteroids are first-line to shorten an acute multiple sclerosis relapse. A short steroid course speeds recovery from disabling attacks, though it does not alter long-term disease course. Interferon beta is a disease-modifying therapy for relapse prevention, baclofen treats spasticity, and plasmapheresis is reserved for steroid-refractory severe relapses rather than routine first-line use.
- A 30-year-old woman is being evaluated for suspected multiple sclerosis. Which cerebrospinal fluid finding most supports this diagnosis?
- Markedly elevated opening pressure with low glucose
- Oligoclonal bands not present in serum
- Neutrophilic pleocytosis with high protein
- Xanthochromia
Correct answer: Oligoclonal bands not present in serum
Cerebrospinal fluid oligoclonal bands absent from serum support multiple sclerosis. They reflect intrathecal immunoglobulin production from the central inflammatory demyelinating process. A neutrophilic pleocytosis with low glucose suggests bacterial meningitis, xanthochromia suggests subarachnoid hemorrhage, and markedly elevated pressure is not characteristic of multiple sclerosis.
- A 26-year-old woman recovering from a multiple sclerosis relapse asks how her disease typically behaves over time in its most common form. Which description best fits the relapsing-remitting pattern?
- Discrete attacks of neurologic symptoms followed by partial or complete recovery
- Steady, uninterrupted decline from onset without distinct attacks
- A single attack that never recurs
- Symptoms only during febrile illnesses that resolve completely
Correct answer: Discrete attacks of neurologic symptoms followed by partial or complete recovery
Relapsing-remitting multiple sclerosis features discrete attacks followed by partial or full recovery between episodes. This is the most common initial pattern, with new or worsening deficits during relapses separated by periods of relative stability. A steady decline from onset describes a primary progressive course, and a single nonrecurring attack or purely febrile symptoms do not define this pattern.
- A 32-year-old man is hospitalized with Guillain-Barre syndrome and ascending weakness. Which bedside measurement is most important to monitor for impending respiratory failure requiring intubation?
- Serial forced vital capacity
- Daily fasting blood glucose
- Hourly intracranial pressure
- Serum sodium concentration
Correct answer: Serial forced vital capacity
Serial forced vital capacity is the key measure for impending respiratory failure in Guillain-Barre syndrome. Progressive weakness of respiratory muscles can precede overt distress, so a falling vital capacity prompts intensive monitoring and possible intubation. Blood glucose, intracranial pressure, and serum sodium do not track neuromuscular respiratory failure here.
- A 40-year-old man with Guillain-Barre syndrome is found to have prominent autonomic instability. Which clinical manifestation reflects this autonomic involvement?
- Bilateral papilledema
- A fixed sensory level at the nipple line
- Resting tremor and cogwheel rigidity
- Wide swings in blood pressure and cardiac arrhythmias
Correct answer: Wide swings in blood pressure and cardiac arrhythmias
Labile blood pressure and arrhythmias reflect the autonomic dysfunction of Guillain-Barre syndrome. Autonomic instability can cause dangerous swings in heart rate and blood pressure, requiring close cardiac monitoring. A sensory level indicates a spinal cord lesion, resting tremor and rigidity indicate parkinsonism, and papilledema reflects raised intracranial pressure.
- A 45-year-old man develops progressive symmetric weakness and absent deep tendon reflexes one week after a diarrheal illness, and Guillain-Barre syndrome is suspected. Which lumbar puncture finding is most characteristic of this disorder?
- Elevated protein with a normal cell count
- Low glucose with neutrophilic pleocytosis
- Numerous red blood cells with xanthochromia
- Elevated cell count with elevated glucose
Correct answer: Elevated protein with a normal cell count
Elevated cerebrospinal fluid protein with a normal cell count, called albuminocytologic dissociation, is characteristic of Guillain-Barre syndrome. The inflammatory demyelination raises protein while leaving the cell count near normal. Low glucose with neutrophils suggests bacterial meningitis, red blood cells with xanthochromia suggest subarachnoid hemorrhage, and a high cell count is not expected.
- A 29-year-old woman with episodic migraines has attacks four or more times per month that significantly impair her work despite acute treatment. Which medication class is most appropriate to start for migraine prophylaxis?
- A short-acting benzodiazepine
- A beta-blocker such as propranolol
- An oral decongestant
- A daily opioid analgesic
Correct answer: A beta-blocker such as propranolol
A beta-blocker such as propranolol is an appropriate first-line preventive for frequent disabling migraines. Daily prophylaxis reduces attack frequency and severity when acute therapy alone is insufficient. Benzodiazepines and decongestants are not migraine preventives, and daily opioids risk dependence and medication-overuse headache.
- A 34-year-old woman has acute moderate-to-severe migraine attacks unresponsive to over-the-counter analgesics. Which medication class works specifically as a migraine-targeted abortive therapy?
- Inhaled corticosteroids
- Loop diuretics
- Proton pump inhibitors
- Triptans
Correct answer: Triptans
Triptans are migraine-specific abortive agents for moderate-to-severe attacks. As serotonin receptor agonists they cause cranial vasoconstriction and reduce neurogenic inflammation to abort the attack. Loop diuretics, proton pump inhibitors, and inhaled corticosteroids have no role in aborting migraine.
- A 36-year-old woman with migraine with aura who smokes asks about contraception. Why is a combined estrogen-containing oral contraceptive generally avoided in this scenario?
- It abolishes the protective effect of triptans
- It causes medication-overuse headache directly
- It increases the risk of ischemic stroke in this group
- It worsens the resting tremor of migraine
Correct answer: It increases the risk of ischemic stroke in this group
Combined estrogen-containing contraceptives are generally avoided in women with migraine with aura because they raise ischemic stroke risk, especially with additional factors like smoking. The aura and estrogen exposure compound cerebrovascular risk. Estrogen does not cause medication-overuse headache, block triptans, or affect a migraine tremor.
- A 22-year-old man presents with fever, headache, neck stiffness, and photophobia. Which is the most important immediate diagnostic step to confirm bacterial meningitis once it can be safely performed?
- Carotid duplex ultrasound
- Electroencephalography
- Lumbar puncture for cerebrospinal fluid analysis
- Nerve conduction studies
Correct answer: Lumbar puncture for cerebrospinal fluid analysis
Lumbar puncture for cerebrospinal fluid analysis is the key confirmatory test for bacterial meningitis. Cell count, glucose, protein, Gram stain, and culture establish the diagnosis and guide therapy, though antibiotics should not be delayed for the procedure. Electroencephalography, carotid ultrasound, and nerve conduction studies do not diagnose meningitis.
- A 19-year-old man with suspected bacterial meningitis has a depressed level of consciousness and a new focal neurologic deficit. Which action is most appropriate before performing a lumbar puncture in this patient?
- Obtain neuroimaging of the head first
- Withhold all antibiotics until the puncture
- Perform the puncture immediately without imaging
- Cancel the puncture permanently
Correct answer: Obtain neuroimaging of the head first
Head imaging before lumbar puncture is appropriate when focal deficits or decreased consciousness raise concern for a mass effect. Imaging reduces the risk of herniation from the procedure, but empiric antibiotics and steroids should be started before imaging to avoid delay. Performing the puncture without imaging, withholding antibiotics, or canceling it outright are inappropriate.
- A 25-year-old woman with suspected bacterial meningitis is being treated empirically. Which adjunctive therapy given early, particularly with pneumococcal disease, reduces neurologic complications?
- Therapeutic anticoagulation
- Mannitol infusion
- Dexamethasone
- Antiepileptic prophylaxis for all patients
Correct answer: Dexamethasone
Adjunctive dexamethasone given early reduces neurologic complications in bacterial meningitis, especially pneumococcal disease. It blunts the inflammatory response that contributes to hearing loss and other sequelae and is given with or just before the first antibiotic dose. Mannitol, anticoagulation, and routine antiepileptic prophylaxis are not standard adjuncts.
- A 55-year-old woman with myasthenia gravis is suspected of having a myasthenic crisis with increasing weakness. Which clinical development most defines a crisis and signals a medical emergency?
- Mild fatigue relieved by rest
- Isolated drooping of one eyelid
- Respiratory muscle weakness requiring ventilatory support
- A transient resting tremor
Correct answer: Respiratory muscle weakness requiring ventilatory support
Myasthenic crisis is defined by respiratory muscle weakness severe enough to require ventilatory support. Weakness of the diaphragm and accessory muscles produces respiratory failure that is life-threatening and may need intubation plus immunotherapy. Isolated ptosis, mild fatigue, and a resting tremor do not constitute crisis.
- A 32-year-old woman reports fluctuating drooping eyelids and double vision that worsen as the day progresses and improve after rest, and myasthenia gravis is suspected. Which antibody is most specific for confirming this diagnosis?
- Antimitochondrial antibodies
- Anti-double-stranded DNA antibodies
- Acetylcholine receptor antibodies
- Anti-cyclic citrullinated peptide antibodies
Correct answer: Acetylcholine receptor antibodies
Acetylcholine receptor antibodies are highly specific for myasthenia gravis. They mediate the autoimmune attack at the postsynaptic neuromuscular junction, producing fatigable weakness that worsens with use. Anti-double-stranded DNA antibodies indicate lupus, antimitochondrial antibodies indicate primary biliary cholangitis, and anti-cyclic citrullinated peptide antibodies indicate rheumatoid arthritis.
- A 45-year-old woman newly diagnosed with myasthenia gravis is referred for chest imaging. Which associated structural abnormality is most important to evaluate for in this disease?
- Adrenal adenoma
- Thymic abnormality such as thymoma or hyperplasia
- Pituitary macroadenoma
- Renal artery stenosis
Correct answer: Thymic abnormality such as thymoma or hyperplasia
Patients with myasthenia gravis should be evaluated for a thymic abnormality such as thymoma or hyperplasia. The thymus is implicated in the autoimmune process, and identifying a thymoma can lead to thymectomy that may improve disease. Adrenal, pituitary, and renal artery lesions are not characteristically linked to myasthenia gravis.
- A 50-year-old woman with sudden onset of the worst headache of her life is found to have a subarachnoid hemorrhage. The initial noncontrast CT is performed promptly. Which test should be performed if the CT is negative but clinical suspicion remains high?
- Lumbar puncture looking for xanthochromia
- Nerve conduction studies
- Electroencephalography
- Carotid duplex ultrasound
Correct answer: Lumbar puncture looking for xanthochromia
When CT is negative but subarachnoid hemorrhage is still suspected, lumbar puncture looking for xanthochromia is the next step. Breakdown of red blood cells yields xanthochromia in the cerebrospinal fluid, supporting the diagnosis the CT may have missed, especially after several hours. Nerve conduction studies, electroencephalography, and carotid ultrasound do not detect subarachnoid blood.
- A 47-year-old woman is admitted with aneurysmal subarachnoid hemorrhage. Which medication is given to reduce the risk of delayed cerebral ischemia from vasospasm?
- Mannitol
- Nimodipine
- Atorvastatin
- Levetiracetam
Correct answer: Nimodipine
Nimodipine is given after aneurysmal subarachnoid hemorrhage to reduce delayed cerebral ischemia. This calcium channel blocker improves neurologic outcomes related to vasospasm in the days after the bleed. Mannitol treats raised intracranial pressure, statins are not used for this indication, and levetiracetam is an antiseizure agent, not vasospasm prophylaxis.
- A 40-year-old man describes the abrupt onset of an explosive headache that reached maximal intensity within seconds and is now the most severe he has ever had. This thunderclap headache should most urgently prompt evaluation for which condition?
- Cervicogenic headache
- Tension-type headache
- Chronic sinusitis
- Subarachnoid hemorrhage
Correct answer: Subarachnoid hemorrhage
A thunderclap headache reaching peak intensity within seconds should urgently prompt evaluation for subarachnoid hemorrhage. The sudden, severe, maximal-at-onset pain is the hallmark presentation of aneurysmal rupture and requires immediate imaging. Tension headache builds gradually, and sinusitis and cervicogenic headache do not produce this explosive onset.
- A 60-year-old man reports recurrent episodes of sudden, severe, electric shock-like pain in the right cheek and jaw triggered by chewing, brushing his teeth, or a light breeze, each lasting seconds. The pain follows the distribution of which cranial nerve?
- Hypoglossal nerve
- Facial nerve
- Glossopharyngeal nerve
- Trigeminal nerve
Correct answer: Trigeminal nerve
Paroxysmal lancinating facial pain triggered by light touch and chewing follows the trigeminal nerve distribution, defining trigeminal neuralgia. The pain affects one or more trigeminal divisions and is provoked by innocuous stimuli to trigger zones. The facial nerve mediates movement, the glossopharyngeal nerve causes throat pain, and the hypoglossal nerve controls the tongue.
- A 58-year-old woman is diagnosed with trigeminal neuralgia. Which medication is the most appropriate first-line pharmacologic treatment?
- Acetaminophen
- Ibuprofen
- Amitriptyline
- Carbamazepine
Correct answer: Carbamazepine
Carbamazepine is the first-line treatment for trigeminal neuralgia. This anticonvulsant reduces the frequency and severity of the paroxysmal neuropathic facial pain. Nonsteroidal anti-inflammatory drugs and acetaminophen are ineffective for this neuropathic pain, and while tricyclics help some neuropathic pain, carbamazepine is the established first-line agent here.
- A 55-year-old woman with refractory trigeminal neuralgia is being counseled that secondary causes should be considered, particularly in younger patients or with atypical features. Which underlying condition is a recognized secondary cause of trigeminal neuralgia?
- Hypothyroidism
- Iron deficiency anemia
- Multiple sclerosis
- Carpal tunnel syndrome
Correct answer: Multiple sclerosis
Multiple sclerosis is a recognized secondary cause of trigeminal neuralgia, particularly in younger patients or with bilateral symptoms. Demyelinating plaques affecting the trigeminal pathway can produce the same lancinating facial pain. Iron deficiency anemia, hypothyroidism, and carpal tunnel syndrome are not causes of trigeminal neuralgia.
- A 26-year-old obese woman has months of daily headache, transient visual obscurations, and pulsatile tinnitus, with bilateral papilledema but normal neuroimaging and elevated opening pressure on lumbar puncture. Which diagnosis best fits this presentation?
- Cluster headache
- Idiopathic intracranial hypertension
- Bell palsy
- Essential tremor
Correct answer: Idiopathic intracranial hypertension
Headache with papilledema, transient visual obscurations, and elevated opening pressure with normal imaging defines idiopathic intracranial hypertension. It classically affects young women with obesity and threatens vision if untreated, often managed with acetazolamide and weight loss. Cluster headache, Bell palsy, and essential tremor do not cause papilledema or raised cerebrospinal fluid pressure.
- A 50-year-old man complains of numbness and tingling on the lateral aspect of his right thigh after recent weight gain and tight belts, with no weakness or reflex change. Compression of which nerve best explains this meralgia paresthetica?
- Tibial nerve
- Common peroneal nerve
- Lateral femoral cutaneous nerve
- Obturator nerve
Correct answer: Lateral femoral cutaneous nerve
Numbness over the lateral thigh without motor deficit indicates compression of the lateral femoral cutaneous nerve, called meralgia paresthetica. Entrapment near the inguinal ligament, worsened by obesity or tight clothing, produces purely sensory symptoms. The common peroneal nerve causes foot drop, the tibial nerve affects plantar function, and the obturator nerve affects the medial thigh.
- A 45-year-old man develops sudden inability to dorsiflex the right foot after sitting cross-legged for a prolonged period, with a slapping gait and numbness over the dorsum of the foot. Compression of which nerve at the fibular head is the most likely cause?
- Femoral nerve
- Common peroneal (fibular) nerve
- Sciatic nerve at the buttock
- Pudendal nerve
Correct answer: Common peroneal (fibular) nerve
Foot drop with sensory loss over the dorsum of the foot after leg compression points to common peroneal nerve injury at the fibular head. The nerve is superficial there and vulnerable to compression, impairing dorsiflexion and eversion. The femoral nerve affects knee extension, a proximal sciatic lesion causes broader deficits, and the pudendal nerve serves the perineum.
- A 30-year-old woman presents with subacute bilateral leg weakness, a clear sensory level at the umbilicus, and bowel and bladder dysfunction, with imaging showing inflammation across a segment of the spinal cord. Which diagnosis best fits this presentation?
- Transverse myelitis
- Bell palsy
- Carpal tunnel syndrome
- Cluster headache
Correct answer: Transverse myelitis
A sensory level with bilateral motor and sphincter dysfunction from cord inflammation indicates transverse myelitis. Inflammatory injury across a spinal cord segment produces weakness, a discrete sensory level, and autonomic involvement below the lesion. Bell palsy affects the face, carpal tunnel syndrome is a focal hand neuropathy, and cluster headache is a primary headache disorder.
- A 45-year-old man with sudden severe lower back pain and bilateral leg weakness now has urinary retention, saddle anesthesia, and decreased rectal tone. Which diagnosis requires the most urgent surgical evaluation?
- Bell palsy
- Lumbar muscle strain
- Migraine headache
- Cauda equina syndrome
Correct answer: Cauda equina syndrome
Saddle anesthesia, urinary retention, and reduced rectal tone with bilateral leg weakness indicate cauda equina syndrome, a surgical emergency. Compression of the lumbosacral nerve roots threatens permanent bowel, bladder, and motor dysfunction without prompt decompression. A simple muscle strain lacks these red flags, and migraine and Bell palsy are unrelated.
- A 7-year-old boy is brought in with fever, headache, and lethargy that progressed to confusion and a seizure over a day. Magnetic resonance imaging shows a ring-enhancing lesion with surrounding edema, and he has a history of chronic otitis media. Which diagnosis is most likely?
- Essential tremor
- Migraine headache
- Brain abscess
- Bell palsy
Correct answer: Brain abscess
A ring-enhancing lesion with edema and a contiguous infection source such as chronic ear disease suggests a brain abscess. Bacteria can spread to the brain and form a focal pus collection, producing headache, fever, focal deficits, or seizures, and requiring imaging plus antibiotics and often drainage. Migraine, essential tremor, and Bell palsy do not produce ring-enhancing brain lesions.
- A 6-month-old infant presents with a bulging anterior fontanelle, increasing head circumference crossing percentiles, and downward deviation of the eyes. Imaging shows enlarged ventricles from impaired cerebrospinal fluid flow. Which condition does this represent?
- Migraine headache
- Bell palsy
- Hydrocephalus
- Carpal tunnel syndrome
Correct answer: Hydrocephalus
A bulging fontanelle, rapidly enlarging head, and downward gaze in an infant with enlarged ventricles indicate hydrocephalus. Accumulation of cerebrospinal fluid from obstructed flow or impaired absorption raises intracranial pressure before the sutures fuse. Bell palsy, migraine, and carpal tunnel syndrome do not cause ventriculomegaly or these infant findings.
- A 40-year-old woman undergoing rapid correction of severe hyponatremia develops, several days later, progressive quadriparesis, dysarthria, and difficulty swallowing. Which complication of overly rapid sodium correction does this describe?
- Osmotic demyelination syndrome
- Guillain-Barre syndrome
- Bell palsy
- Cluster headache
Correct answer: Osmotic demyelination syndrome
Quadriparesis and bulbar dysfunction days after rapid sodium correction describe osmotic demyelination syndrome, classically central pontine myelinolysis. Too-rapid correction of chronic hyponatremia injures pontine myelin, so sodium must be raised slowly. Guillain-Barre follows infection with ascending weakness, Bell palsy is a focal facial palsy, and cluster headache is a primary headache.
- A 50-year-old chronic alcohol user presents with confusion, gait ataxia, and horizontal nystagmus with impaired eye movements. Urgent administration of which treatment is most appropriate to prevent permanent neurologic damage?
- Intramuscular epinephrine
- Intravenous mannitol
- Oral carbamazepine
- Intravenous thiamine
Correct answer: Intravenous thiamine
The triad of confusion, ataxia, and ophthalmoplegia in an alcohol user is Wernicke encephalopathy, treated urgently with intravenous thiamine. Prompt thiamine repletion, given before glucose, can reverse the deficit and prevent progression to irreversible Korsakoff amnesia. Mannitol, carbamazepine, and epinephrine do not treat this thiamine-deficiency syndrome.
- A 60-year-old man with hypertension develops acute vertigo, vomiting, severe occipital headache, and inability to walk, with imaging showing a cerebellar hemorrhage. Why is this location a neurosurgical emergency requiring close monitoring?
- It invariably causes only a benign self-limited headache
- Expanding mass in the posterior fossa can compress the brainstem and cause obstructive hydrocephalus
- It selectively damages peripheral nerves
- It produces an isolated facial palsy
Correct answer: Expanding mass in the posterior fossa can compress the brainstem and cause obstructive hydrocephalus
A cerebellar hemorrhage is dangerous because an expanding posterior fossa mass can compress the brainstem and obstruct cerebrospinal fluid flow, causing hydrocephalus and rapid deterioration. Surgical decompression may be required, so close monitoring is essential. It is not a benign headache, does not selectively injure peripheral nerves, and does not present as an isolated facial palsy.
- A 35-year-old man sustains a fracture of the surgical neck of the humerus and afterward cannot abduct the arm to the side and has numbness over the lateral shoulder. Injury to which nerve best explains these findings?
- Median nerve
- Axillary nerve
- Ulnar nerve
- Radial nerve
Correct answer: Axillary nerve
Loss of shoulder abduction with numbness over the lateral shoulder after a surgical neck humerus fracture indicates axillary nerve injury. The axillary nerve innervates the deltoid and supplies sensation over the lateral shoulder, and it is vulnerable at this fracture site. The median and ulnar nerves serve the hand, and the radial nerve injury causes wrist drop.
- A 68-year-old man with prior transient ischemic attacks is found to have a 75% stenosis of the symptomatic internal carotid artery. Which intervention is most appropriate to reduce his risk of future ischemic stroke?
- Lifelong bed rest
- Carotid endarterectomy
- Routine cerebral angiography every month
- High-dose vitamin supplementation
Correct answer: Carotid endarterectomy
Carotid endarterectomy reduces future stroke risk in symptomatic high-grade internal carotid stenosis. Removing the atherosclerotic plaque from a recently symptomatic, severely stenotic carotid artery lowers the risk of subsequent ischemic stroke when combined with medical therapy. Bed rest, repeated angiography, and vitamin supplements do not address the stenotic lesion.
- A 60-year-old man with poorly controlled diabetes develops sudden, painful inability to move the right eye inward and upward with a drooping eyelid, but the pupil reacts normally to light. Which cranial nerve is most likely affected, and what does pupil sparing suggest?
- Oculomotor nerve palsy from microvascular ischemia, with pupil sparing suggesting a benign cause
- Optic nerve damage causing complete blindness
- Facial nerve palsy causing forehead weakness
- Trigeminal nerve injury causing facial numbness
Correct answer: Oculomotor nerve palsy from microvascular ischemia, with pupil sparing suggesting a benign cause
A pupil-sparing third nerve palsy in a diabetic suggests microvascular ischemic oculomotor neuropathy. Ischemia tends to affect the central motor fibers while sparing the peripheral pupillary fibers, so a reactive pupil points away from a compressive aneurysm. The optic, facial, and trigeminal nerves do not control these eye movements or eyelid elevation.
- A 30-year-old man with schizophrenia has predominantly negative symptoms, including flat affect, poverty of speech, and social withdrawal, which persist despite control of his hallucinations on an antipsychotic. Which feature is correctly classified as a negative symptom rather than a positive symptom?
- Avolition, the reduced ability to initiate and persist in goal-directed activity
- Auditory hallucinations of a commenting voice
- Bizarre persecutory delusions
- Disorganized, derailed speech
Correct answer: Avolition, the reduced ability to initiate and persist in goal-directed activity
Avolition is the negative symptom here. Negative symptoms reflect a loss or reduction of normal function and include the five classic A's: affective flattening, alogia (poverty of speech), anhedonia, asociality, and avolition. Hallucinations, delusions, and disorganized speech are positive symptoms because they represent an excess or distortion of normal function, not a deficit.
- A 24-year-old man with schizophrenia is started on risperidone and after several weeks develops breast tenderness and galactorrhea. Which mechanism best explains these adverse effects?
- Blockade of histamine H1 receptors
- Blockade of dopamine in the tuberoinfundibular pathway raising prolactin
- Antagonism of muscarinic receptors
- Agonism at serotonin 5-HT2A receptors
Correct answer: Blockade of dopamine in the tuberoinfundibular pathway raising prolactin
Blockade of tuberoinfundibular dopamine causing hyperprolactinemia is the explanation. Dopamine normally inhibits prolactin release; antipsychotics that strongly block D2 receptors in the tuberoinfundibular pathway, such as risperidone, remove this inhibition and raise prolactin, producing galactorrhea, gynecomastia, and menstrual irregularities. Histamine and muscarinic effects cause sedation and anticholinergic symptoms, not galactorrhea.
- A 26-year-old woman has had paranoid delusions, auditory hallucinations, and disorganized speech for the past 4 weeks following an acute stressor, and she has fully returned to her baseline. Which diagnosis best fits a psychotic episode lasting more than 1 day but less than 1 month with full return to baseline?
- Schizophrenia
- Schizoaffective disorder
- Brief psychotic disorder
- Schizophreniform disorder
Correct answer: Brief psychotic disorder
Brief psychotic disorder is the best fit. It is defined by the sudden onset of one or more psychotic symptoms lasting at least 1 day but less than 1 month, with eventual full return to premorbid functioning, and is often precipitated by a marked stressor. Schizophreniform disorder lasts 1 to 6 months, and schizophrenia requires at least 6 months of disturbance.
- A 23-year-old man newly diagnosed with schizophrenia asks about the prognosis of his illness. Which factor is associated with a more favorable prognosis?
- Insidious onset over many months
- Prominent negative symptoms early in the course
- Younger age at first onset
- Acute onset of symptoms with a clear precipitating stressor
Correct answer: Acute onset of symptoms with a clear precipitating stressor
Acute onset with an identifiable precipitant predicts a better prognosis. Favorable prognostic features in schizophrenia also include later age of onset, prominent mood symptoms, good premorbid functioning, and a strong support system. Insidious onset, early prominent negative symptoms, and very young age at onset all predict a poorer outcome.
- A 28-year-old patient has had 2 months of continuous psychotic symptoms but does not yet meet the 6-month duration required for another diagnosis. The clinician documents schizophreniform disorder. What is the minimum total duration of symptoms required to diagnose schizophrenia instead?
- 6 months
- 1 month
- 3 months
- 12 months
Correct answer: 6 months
Six months is the threshold. Schizophrenia requires continuous signs of the disturbance for at least 6 months, which must include at least 1 month of active-phase symptoms. When the total duration is at least 1 month but less than 6 months, the diagnosis is schizophreniform disorder, which is what this patient currently meets.
- A 19-year-old college student reports that for the past 8 months he has felt excessively worried about grades, his health, and world events nearly every day, with associated restlessness, muscle tension, and trouble sleeping. He has no discrete panic attacks. Which diagnosis is most consistent with this presentation?
- Panic disorder
- Generalized anxiety disorder
- Specific phobia
- Acute stress disorder
Correct answer: Generalized anxiety disorder
Generalized anxiety disorder is most consistent. It is characterized by excessive, difficult-to-control worry about multiple domains occurring more days than not for at least 6 months, accompanied by symptoms such as restlessness, fatigue, difficulty concentrating, irritability, muscle tension, and sleep disturbance. The absence of discrete panic attacks and the chronic generalized worry distinguish it from panic disorder.
- A 45-year-old woman with generalized anxiety disorder has prominent muscle tension and worry but cannot tolerate SSRIs due to sexual side effects. The clinician considers a non-antidepressant agent that is a serotonin 5-HT1A partial agonist with no dependence potential. Which medication is this?
- Alprazolam
- Propranolol
- Buspirone
- Diphenhydramine
Correct answer: Buspirone
Buspirone is the agent described. It is a serotonin 5-HT1A partial agonist used for generalized anxiety disorder; it lacks sedation, has no abuse or dependence potential, and does not cause the sexual dysfunction associated with SSRIs. It must be taken regularly because its onset is delayed by 2 to 4 weeks, unlike benzodiazepines, which act rapidly but carry dependence risk.
- A patient with generalized anxiety disorder is started on venlafaxine. Compared with an SSRI, what additional pharmacologic action does this serotonin-norepinephrine reuptake inhibitor provide?
- Blockade of dopamine D2 receptors
- Agonism at GABA-A receptors
- Inhibition of monoamine oxidase
- Inhibition of norepinephrine reuptake in addition to serotonin reuptake
Correct answer: Inhibition of norepinephrine reuptake in addition to serotonin reuptake
Norepinephrine reuptake inhibition is the added action. Venlafaxine and duloxetine are serotonin-norepinephrine reuptake inhibitors that block reuptake of both serotonin and norepinephrine, and both are FDA-approved for generalized anxiety disorder. They do not act primarily through dopamine blockade, GABA-A agonism, or monoamine oxidase inhibition.
- A 32-year-old patient with bipolar I disorder is being started on lithium for long-term maintenance. Which baseline laboratory and organ-function tests are most appropriate before initiating therapy?
- Renal function and thyroid function tests
- Liver enzymes and amylase only
- Coagulation studies and platelet count
- Serum cortisol and ACTH
Correct answer: Renal function and thyroid function tests
Baseline renal and thyroid function are essential. Lithium is renally cleared and can cause nephrogenic diabetes insipidus and chronic kidney impairment, and it can induce hypothyroidism, so creatinine and TSH must be checked at baseline and monitored periodically. A pregnancy test and basic electrolytes are also advised given lithium's narrow therapeutic index and teratogenicity.
- A 29-year-old woman with bipolar I disorder is found unresponsive after an overdose. Her lithium level returns markedly elevated with severe neurotoxicity and renal failure. Which intervention is the definitive treatment for severe lithium toxicity?
- Administration of activated charcoal
- Hemodialysis
- Intravenous flumazenil
- Sodium bicarbonate infusion
Correct answer: Hemodialysis
Hemodialysis is the definitive treatment. Lithium is a small, non-protein-bound ion that is effectively removed by dialysis, which is indicated for severe toxicity marked by significantly elevated levels, renal failure, or serious neurologic signs such as seizures or altered consciousness. Activated charcoal does not bind lithium, and flumazenil and bicarbonate do not treat lithium toxicity.
- A 35-year-old woman with bipolar I disorder, currently in a depressive episode, is being treated. Which principle should guide pharmacologic management of bipolar depression?
- Start an SSRI alone as first-line therapy
- Discontinue all mood stabilizers during depressive episodes
- Use a mood stabilizer or antipsychotic rather than antidepressant monotherapy to avoid a manic switch
- Use stimulants as the preferred first-line treatment
Correct answer: Use a mood stabilizer or antipsychotic rather than antidepressant monotherapy to avoid a manic switch
Avoiding antidepressant monotherapy is the guiding principle. In bipolar depression, an antidepressant given without a mood stabilizer can precipitate a switch into mania or induce rapid cycling. Treatment relies on mood stabilizers such as lithium or lamotrigine or on certain second-generation antipsychotics, with antidepressants used cautiously and only alongside a mood stabilizer.
- A 27-year-old man presents with at least 1 week of elevated mood, grandiosity, pressured speech, decreased need for sleep, and reckless spending that has required hospitalization. He has no history of a major depressive episode. Which diagnosis is most accurate?
- Bipolar II disorder
- Cyclothymic disorder
- Major depressive disorder with mixed features
- Bipolar I disorder
Correct answer: Bipolar I disorder
Bipolar I disorder is the accurate diagnosis. It requires at least one full manic episode lasting at least 1 week or any duration if hospitalization is needed, and a prior depressive episode is not required. Bipolar II requires a hypomanic episode plus a major depressive episode, and the severity with hospitalization here defines mania rather than hypomania.
- A 38-year-old man presents with depressed mood, anhedonia, insomnia, poor appetite with weight loss, fatigue, and feelings of worthlessness present nearly every day for 3 weeks. He has had no manic symptoms. How many of the nine core SIGECAPS-type symptoms, including depressed mood or anhedonia, are required for at least 2 weeks to diagnose major depressive disorder?
Correct answer: Five
Five symptoms are required. Major depressive disorder is diagnosed when at least five of nine symptoms are present during the same 2-week period and represent a change from baseline, and at least one must be depressed mood or loss of interest/pleasure. The mnemonic SIGECAPS captures sleep, interest, guilt, energy, concentration, appetite, psychomotor changes, and suicidality.
- A 50-year-old man with major depressive disorder also reports erectile dysfunction and is worried that an antidepressant will worsen it. The clinician selects an agent with a low rate of sexual side effects that also aids smoking cessation. Which antidepressant is most appropriate?
- Paroxetine
- Bupropion
- Sertraline
- Venlafaxine
Correct answer: Bupropion
Bupropion is most appropriate. It is a norepinephrine-dopamine reuptake inhibitor with a notably low incidence of sexual dysfunction and is also approved for smoking cessation. It should be avoided in patients with seizure disorders or eating disorders because it lowers the seizure threshold. SSRIs and SNRIs commonly cause sexual side effects.
- A 62-year-old woman with severe major depressive disorder has psychotic features, refuses to eat or drink, and is acutely suicidal, and she has failed multiple medication trials. Which treatment offers the most rapid and effective response in this situation?
- Adding a low-dose benzodiazepine
- Switching to a different SSRI
- Electroconvulsive therapy
- Starting cognitive behavioral therapy alone
Correct answer: Electroconvulsive therapy
Electroconvulsive therapy is the most appropriate choice. It produces rapid, highly effective improvement and is indicated for severe depression with psychosis, acute suicidality, refusal of food or fluids, catatonia, or failure of multiple medication trials. Its main adverse effect is transient memory impairment, and it is among the most effective treatments for severe, life-threatening depression.
- A 70-year-old man whose wife died 8 months ago reports persistent sadness but is able to experience pleasure during family visits, maintains self-worth, and has no suicidal ideation, with symptoms gradually improving. Which conclusion is most appropriate?
- He meets full criteria for major depressive disorder and needs an antidepressant
- He has persistent complex bereavement requiring hospitalization
- He should be diagnosed with adjustment disorder with anxiety
- His grief is a normal, uncomplicated bereavement reaction rather than major depressive disorder
Correct answer: His grief is a normal, uncomplicated bereavement reaction rather than major depressive disorder
Normal bereavement is the correct conclusion. Uncomplicated grief tends to come in waves, preserves self-esteem, allows moments of pleasure, lacks pervasive worthlessness or active suicidality, and improves over time. Features that suggest a superimposed major depressive episode include persistent worthlessness, marked functional impairment, psychomotor retardation, and suicidal ideation, which are absent here.
- A 33-year-old woman reports that for many years she has had a chronic low-grade depressed mood present most of the day, more days than not, with poor appetite, low energy, and low self-esteem, but she has never had a 2-week period meeting full criteria for a major depressive episode. Which diagnosis best fits?
- Persistent depressive disorder (dysthymia)
- Major depressive disorder, single episode
- Cyclothymic disorder
- Adjustment disorder with depressed mood
Correct answer: Persistent depressive disorder (dysthymia)
Persistent depressive disorder, formerly dysthymia, is the best fit. It is characterized by a depressed mood for most of the day, more days than not, for at least 2 years in adults, plus at least two additional symptoms such as poor appetite, low energy, or low self-esteem. The chronic, lower-intensity course distinguishes it from a discrete major depressive episode.
- A 28-year-old man with obsessive-compulsive disorder describes intrusive, distressing thoughts that he might have left the stove on, which drive him to repeatedly check the kitchen for hours. Which terms correctly label the intrusive thoughts and the repetitive checking, respectively?
- Compulsions and obsessions
- Obsessions and compulsions
- Delusions and rituals
- Phobias and avoidance behaviors
Correct answer: Obsessions and compulsions
The intrusive thoughts are obsessions and the checking is a compulsion. Obsessions are recurrent, unwanted, intrusive thoughts, urges, or images that cause anxiety, whereas compulsions are repetitive behaviors or mental acts performed to reduce that anxiety or prevent a feared event. In obsessive-compulsive disorder, the person typically recognizes the behaviors as excessive.
- A 30-year-old patient is diagnosed with obsessive-compulsive disorder. The clinician plans first-line pharmacotherapy. Compared with treatment of depression, what is characteristic of SSRI dosing for obsessive-compulsive disorder?
- Lower doses are usually sufficient and effective
- Response is generally seen within the first few days
- Higher doses and a longer time to response are typically required
- Benzodiazepines are the established first-line treatment
Correct answer: Higher doses and a longer time to response are typically required
Higher doses and a longer trial are characteristic. Obsessive-compulsive disorder generally requires higher SSRI doses than depression and a longer time, often 8 to 12 weeks, to achieve adequate response. First-line treatment combines an SSRI with exposure and response prevention, a form of cognitive behavioral therapy; clomipramine is an effective alternative when SSRIs fail.
- A 35-year-old woman with obsessive-compulsive disorder asks which specific type of psychotherapy is considered first-line and most effective for her condition. Which therapy is the correct answer?
- Psychoanalysis focused on childhood conflicts
- Supportive psychotherapy alone
- Eye movement desensitization and reprocessing
- Exposure and response prevention
Correct answer: Exposure and response prevention
Exposure and response prevention is the first-line therapy. This cognitive behavioral technique gradually exposes the patient to anxiety-provoking triggers while preventing the compulsive response, allowing the anxiety to habituate and extinguish over time. It is the most evidence-supported psychotherapy for obsessive-compulsive disorder and is often combined with an SSRI.
- A clinician must distinguish obsessive-compulsive disorder from obsessive-compulsive personality disorder. Which feature is characteristic of obsessive-compulsive personality disorder rather than obsessive-compulsive disorder?
- A pervasive, ego-syntonic preoccupation with orderliness, perfectionism, and control without true obsessions or compulsions
- Intrusive, distressing obsessions that the patient finds unwanted
- Compulsive rituals performed to neutralize anxiety
- Acute onset of contamination fears with hand-washing rituals
Correct answer: A pervasive, ego-syntonic preoccupation with orderliness, perfectionism, and control without true obsessions or compulsions
An ego-syntonic preoccupation with control defines obsessive-compulsive personality disorder. Patients with this personality disorder view their rigidity, perfectionism, and need for control as appropriate and are not distressed by them, and they lack true obsessions and compulsions. In contrast, obsessive-compulsive disorder involves ego-dystonic, unwanted obsessions and anxiety-driven compulsions that the patient wishes to be rid of.
- A 52-year-old man with chronic alcohol use disorder is admitted after his last drink 8 hours ago. He is tremulous, diaphoretic, tachycardic, and hypertensive but alert and oriented. Which clinical syndrome do these early findings most likely represent?
- Delirium tremens
- Uncomplicated alcohol withdrawal
- Wernicke encephalopathy
- Alcoholic hallucinosis with full delirium
Correct answer: Uncomplicated alcohol withdrawal
Uncomplicated alcohol withdrawal best fits. Early withdrawal beginning 6 to 24 hours after the last drink causes tremor, sweating, tachycardia, hypertension, anxiety, and insomnia while the patient remains oriented. Delirium tremens, which involves profound confusion, autonomic instability, and hallucinations, typically appears later at 48 to 96 hours and is a medical emergency.
- A 48-year-old man in alcohol withdrawal develops a generalized tonic-clonic seizure approximately 24 hours after his last drink. What is the most appropriate management of alcohol withdrawal seizures?
- Start long-term phenytoin monotherapy
- Withhold all sedatives to allow the seizure to resolve
- Administer a benzodiazepine, which both treats and prevents further withdrawal seizures
- Administer intravenous haloperidol as first-line therapy
Correct answer: Administer a benzodiazepine, which both treats and prevents further withdrawal seizures
A benzodiazepine is the correct treatment. Benzodiazepines such as lorazepam or diazepam are first-line for alcohol withdrawal because they restore GABAergic tone, terminating and preventing withdrawal seizures and reducing progression to delirium tremens. Phenytoin is not effective for alcohol withdrawal seizures, and antipsychotics like haloperidol lower the seizure threshold.
- A 60-year-old man hospitalized for alcohol withdrawal develops delirium tremens with severe agitation and hallucinations 72 hours after admission. Beyond benzodiazepines, which supportive measure is critical because of the high mortality of this condition?
- Immediate discharge once the patient is calm
- Restriction of intravenous fluids to avoid overload
- Routine administration of glucose before thiamine
- Aggressive supportive care with fluids, electrolyte correction, and thiamine in a monitored setting
Correct answer: Aggressive supportive care with fluids, electrolyte correction, and thiamine in a monitored setting
Aggressive supportive care is critical. Delirium tremens carries significant mortality and demands close monitoring, generous benzodiazepine dosing, intravenous fluids, correction of electrolyte abnormalities such as hypomagnesemia and hypokalemia, and thiamine repletion. Thiamine should be given before or with glucose to avoid precipitating Wernicke encephalopathy.
- A 10-year-old boy is evaluated for attention-deficit/hyperactivity disorder. According to current diagnostic criteria, before what age must several inattentive or hyperactive-impulsive symptoms have been present?
- Before age 12
- Before age 7
- Before age 6
- Before age 18
Correct answer: Before age 12
Symptoms must be present before age 12. Diagnostic criteria require that several inattentive or hyperactive-impulsive symptoms appear before age 12, occur in two or more settings such as home and school, and cause functional impairment for at least 6 months. The earlier age-7 threshold was used in prior criteria but has been revised.
- A 9-year-old boy with attention-deficit/hyperactivity disorder is being started on a stimulant. Which adverse effect should the clinician monitor for during stimulant therapy?
- Weight gain and increased appetite
- Appetite suppression and growth velocity slowing
- Bradycardia and hypotension
- Sedation and excessive drowsiness
Correct answer: Appetite suppression and growth velocity slowing
Appetite suppression with possible growth slowing is the key adverse effect to monitor. Stimulants such as methylphenidate and amphetamine salts commonly reduce appetite, can transiently slow growth, and may cause insomnia, increased heart rate, and elevated blood pressure. Clinicians should track height, weight, and cardiovascular vital signs during treatment.
- A 7-year-old child with attention-deficit/hyperactivity disorder has a family history concerning for sudden cardiac death, and the parents prefer a non-stimulant option. Which selective norepinephrine reuptake inhibitor is approved as a non-stimulant treatment for this condition?
- Methylphenidate
- Lisdexamfetamine
- Atomoxetine
- Buspirone
Correct answer: Atomoxetine
Atomoxetine is the non-stimulant option. It is a selective norepinephrine reuptake inhibitor approved for attention-deficit/hyperactivity disorder and is useful when stimulants are contraindicated, poorly tolerated, or undesired, such as with concerns about abuse or tics. Alpha-2 agonists like guanfacine and clonidine are additional non-stimulant choices.
- A 16-year-old girl with anorexia nervosa, restricting type, is severely malnourished. Which physical examination or laboratory finding is most characteristic of her condition?
- Hypertension with tachycardia
- Obesity with acanthosis nigricans
- Hyperthermia and flushing
- Bradycardia with hypotension and lanugo hair
Correct answer: Bradycardia with hypotension and lanugo hair
Bradycardia, hypotension, and lanugo are characteristic. Starvation in anorexia nervosa produces bradycardia, hypotension, hypothermia, fine downy lanugo hair, amenorrhea, and electrolyte disturbances. These reflect the body's adaptation to severe caloric restriction and contribute to anorexia nervosa having one of the highest mortality rates among psychiatric disorders.
- A severely malnourished 17-year-old with anorexia nervosa is hospitalized and aggressively refed. On day 3 she develops weakness, confusion, and cardiac arrhythmias. Which electrolyte abnormality is the hallmark of refeeding syndrome responsible for these findings?
- Hypophosphatemia
- Hypercalcemia
- Hypernatremia
- Hyperphosphatemia
Correct answer: Hypophosphatemia
Hypophosphatemia is the hallmark. When carbohydrate intake resumes after starvation, the insulin surge drives phosphate, potassium, and magnesium into cells, and the resulting hypophosphatemia can cause cardiac arrhythmias, respiratory failure, and neurologic dysfunction. Refeeding must be slow with careful electrolyte monitoring and supplementation to prevent this potentially fatal complication.
- A 24-year-old woman of normal weight reports recurrent episodes of binge eating followed by self-induced vomiting, and on examination she has eroded dental enamel, parotid gland swelling, and calluses on the dorsum of her hand. Which diagnosis do these findings indicate?
- Anorexia nervosa, restricting type
- Bulimia nervosa
- Binge eating disorder
- Avoidant/restrictive food intake disorder
Correct answer: Bulimia nervosa
Bulimia nervosa is indicated. It involves recurrent binge eating with compensatory purging in a patient whose weight is usually normal or near-normal, and chronic self-induced vomiting produces dental enamel erosion, parotid hypertrophy, and Russell sign, the knuckle calluses from inducing vomiting. Hypokalemic, hypochloremic metabolic alkalosis is a common laboratory finding.
- A clinician selects an antidepressant for a patient with bulimia nervosa but must avoid one agent specifically because of its risk in this population. Which antidepressant is contraindicated in bulimia nervosa due to an increased seizure risk?
- Fluoxetine
- Sertraline
- Bupropion
- Citalopram
Correct answer: Bupropion
Bupropion is contraindicated in bulimia nervosa. It lowers the seizure threshold, and patients with eating disorders who purge and have electrolyte disturbances are at substantially increased risk of seizures, so bupropion is contraindicated. Fluoxetine is the SSRI specifically FDA-approved for bulimia nervosa and is the preferred pharmacologic agent.
- A 35-year-old combat veteran reports that for the past 6 months, following an explosion that killed a fellow soldier, he has had nightmares, flashbacks, avoidance of reminders, emotional numbing, and exaggerated startle. Which diagnosis is most appropriate given the duration of symptoms?
- Acute stress disorder
- Adjustment disorder
- Generalized anxiety disorder
- Post-traumatic stress disorder
Correct answer: Post-traumatic stress disorder
Post-traumatic stress disorder is appropriate. It follows exposure to actual or threatened death or serious injury and includes intrusion symptoms such as flashbacks and nightmares, avoidance, negative alterations in mood and cognition, and hyperarousal lasting longer than 1 month. When the identical symptom cluster lasts only 3 days to 1 month, the diagnosis is acute stress disorder.
- A patient with post-traumatic stress disorder has distressing trauma-related nightmares that persist despite SSRI therapy and trauma-focused psychotherapy. Which medication is specifically used to reduce nightmares in this condition?
- Prazosin
- Lorazepam
- Lithium
- Quetiapine
Correct answer: Prazosin
Prazosin is the agent used for nightmares. This alpha-1 adrenergic antagonist reduces the sympathetic arousal that drives trauma-related nightmares and sleep disturbance in post-traumatic stress disorder. SSRIs such as sertraline and paroxetine are first-line for the overall disorder, but prazosin specifically targets nightmares; benzodiazepines are generally avoided due to dependence risk and limited benefit.
- A 26-year-old man witnessed a fatal car crash 1 week ago and now has intrusive memories, dissociation, avoidance, and hyperarousal that markedly impair his functioning. The symptoms have lasted 7 days. Which diagnosis is most accurate at this point?
- Post-traumatic stress disorder
- Acute stress disorder
- Adjustment disorder with anxiety
- Brief psychotic disorder
Correct answer: Acute stress disorder
Acute stress disorder is most accurate. It applies when trauma-related intrusion, dissociation, avoidance, and arousal symptoms occur from 3 days to 1 month after exposure to a traumatic event. If the same symptoms persist beyond 1 month, the diagnosis transitions to post-traumatic stress disorder. The 7-day duration here fits acute stress disorder.
- A 28-year-old woman describes recurrent, unexpected surges of intense fear peaking within minutes, with palpitations, chest tightness, shortness of breath, and a fear of dying, followed by persistent worry about future attacks. Which diagnosis best fits?
- Generalized anxiety disorder
- Specific phobia
- Panic disorder
- Illness anxiety disorder
Correct answer: Panic disorder
Panic disorder best fits. It is defined by recurrent unexpected panic attacks, which are abrupt surges of intense fear peaking within minutes with somatic symptoms such as palpitations, dyspnea, and chest discomfort, plus at least 1 month of persistent concern about additional attacks or maladaptive behavioral change. The unexpected nature and anticipatory worry distinguish it from generalized anxiety disorder.
- A 30-year-old man with panic disorder needs both acute symptom relief and long-term prevention. Which combination represents the standard pharmacologic approach?
- A benzodiazepine alone indefinitely
- An antipsychotic for long-term control
- A stimulant for acute attacks
- An SSRI for long-term control with a benzodiazepine for short-term bridging
Correct answer: An SSRI for long-term control with a benzodiazepine for short-term bridging
An SSRI for maintenance with short-term benzodiazepine bridging is standard. SSRIs are first-line for long-term prevention of panic disorder but take weeks to work, so a benzodiazepine may be used briefly at the start for rapid relief and then tapered to avoid dependence. Cognitive behavioral therapy is also a highly effective core treatment.
- A 22-year-old man avoids parties, public speaking, and eating in restaurants because he fears scrutiny and humiliation, and these fears have impaired his work and social life for over a year. Which diagnosis is most consistent with his presentation?
- Social anxiety disorder
- Agoraphobia
- Schizoid personality disorder
- Avoidant/restrictive food intake disorder
Correct answer: Social anxiety disorder
Social anxiety disorder is most consistent. It involves marked, persistent fear of social or performance situations in which the person fears negative evaluation or embarrassment, leading to avoidance and impairment lasting 6 months or more. SSRIs and cognitive behavioral therapy are first-line, and beta-blockers can help with performance-only subtypes.
- A 78-year-old man hospitalized for a urinary tract infection develops acute-onset, fluctuating confusion with inattention, disorganized thinking, and visual hallucinations that worsen at night. Which diagnosis best explains this presentation?
- Major neurocognitive disorder (dementia)
- Delirium
- Schizophrenia
- Major depressive disorder with psychotic features
Correct answer: Delirium
Delirium best explains this picture. It is an acute, fluctuating disturbance of attention and awareness, often with disorganized thinking and perceptual disturbances, caused by a medical condition such as infection, medication, or metabolic derangement. Its acute onset, waxing and waning course, and prominent inattention distinguish it from the gradual, stable memory decline of dementia.
- A 75-year-old woman has a 4-year history of gradually progressive memory loss with preserved alertness, no fluctuation in attention, and intact level of consciousness. Which feature most reliably distinguishes her condition from delirium?
- Acute onset over hours to days
- Marked fluctuation in attention throughout the day
- Gradual onset with a clear, stable level of consciousness
- Reversibility once the underlying cause is treated
Correct answer: Gradual onset with a clear, stable level of consciousness
Gradual onset with preserved, stable consciousness distinguishes dementia. Major neurocognitive disorder develops insidiously over months to years with a stable, alert level of consciousness, whereas delirium has acute onset, a fluctuating course, clouded consciousness, and prominent inattention. Recognizing this difference is essential because delirium is often reversible if its cause is identified and treated.
- A 60-year-old woman reports multiple distressing physical symptoms over the past year, including fatigue and pain, accompanied by excessive thoughts, persistent anxiety, and time-consuming preoccupation with her health, even though evaluations have been largely unrevealing. Which diagnosis best fits?
- Illness anxiety disorder
- Conversion disorder
- Factitious disorder
- Somatic symptom disorder
Correct answer: Somatic symptom disorder
Somatic symptom disorder best fits. It involves one or more distressing somatic symptoms accompanied by excessive thoughts, feelings, or behaviors related to those symptoms and disproportionate health concern persisting for more than 6 months. Unlike illness anxiety disorder, actual somatic symptoms are present, and unlike factitious disorder, the symptoms are not intentionally produced.
- A 26-year-old patient on a stable SSRI is also given a triptan and tramadol and develops agitation, hyperthermia, diaphoresis, tremor, and inducible clonus with hyperreflexia. Which condition does this clinical picture represent?
- Serotonin syndrome
- Neuroleptic malignant syndrome
- Anticholinergic toxicity
- Malignant hyperthermia
Correct answer: Serotonin syndrome
Serotonin syndrome is represented. It results from excess serotonergic activity, often from combining serotonergic agents such as SSRIs, triptans, tramadol, or MAO inhibitors, and presents with the triad of mental status change, autonomic instability, and neuromuscular hyperactivity featuring clonus and hyperreflexia. Treatment includes stopping the offending agents, supportive care, and cyproheptadine in severe cases.
- A 30-year-old man with schizophrenia is started on a high-potency first-generation antipsychotic and within hours develops a sustained, painful contraction of the neck muscles with the head twisted to one side. Which extrapyramidal reaction is this, and what is the appropriate treatment?
- Tardive dyskinesia treated by stopping the drug only
- Acute dystonia treated with an anticholinergic such as benztropine or diphenhydramine
- Akathisia treated with a beta-blocker
- Neuroleptic malignant syndrome treated with dantrolene
Correct answer: Acute dystonia treated with an anticholinergic such as benztropine or diphenhydramine
This is acute dystonia treated with an anticholinergic. Acute dystonic reactions are sudden, sustained muscle contractions such as torticollis, oculogyric crisis, or laryngospasm that occur soon after starting high-potency antipsychotics and respond rapidly to anticholinergics like benztropine or diphenhydramine. Akathisia, tardive dyskinesia, and neuroleptic malignant syndrome are distinct extrapyramidal complications with different management.
- A 40-year-old man on haloperidol for several days develops high fever, severe muscular rigidity, autonomic instability, altered mental status, and a markedly elevated creatine kinase. Which life-threatening condition does this represent, and what is a key treatment?
- Serotonin syndrome treated with cyproheptadine
- Acute dystonia treated with benztropine
- Neuroleptic malignant syndrome treated by stopping the antipsychotic and giving dantrolene or bromocriptine
- Tardive dyskinesia treated with valbenazine
Correct answer: Neuroleptic malignant syndrome treated by stopping the antipsychotic and giving dantrolene or bromocriptine
This is neuroleptic malignant syndrome. It is a rare, life-threatening reaction to dopamine-blocking antipsychotics marked by the tetrad of hyperthermia, lead-pipe rigidity, autonomic instability, and altered mental status with elevated creatine kinase. Management includes immediate discontinuation of the offending agent, aggressive supportive care, and dantrolene or the dopamine agonist bromocriptine.
- A 21-year-old man is brought to the emergency department after using a drug at a party. He is agitated and violent, with vertical and horizontal nystagmus, hypertension, and marked analgesia, and he reports distorted perceptions. Intoxication with which substance is most likely?
- Heroin
- Alcohol
- Benzodiazepines
- Phencyclidine (PCP)
Correct answer: Phencyclidine (PCP)
Phencyclidine intoxication is most likely. PCP characteristically produces violent agitation, both vertical and horizontal nystagmus, hypertension, tachycardia, and profound analgesia along with hallucinations and dissociation. The combination of nystagmus in multiple directions with severe agitation and analgesia is a classic clue distinguishing PCP from opioid or sedative intoxication.
- A 25-year-old man is brought in with euphoria, dilated pupils, tachycardia, hypertension, hyperthermia, and paranoid agitation after binge use of a stimulant. Which class of substance best explains this toxidrome?
- Cocaine or amphetamine (sympathomimetic stimulant)
- Opioid
- Benzodiazepine
- Cannabis
Correct answer: Cocaine or amphetamine (sympathomimetic stimulant)
A sympathomimetic stimulant such as cocaine or amphetamine best explains it. Stimulant intoxication produces a sympathomimetic toxidrome of mydriasis, tachycardia, hypertension, hyperthermia, diaphoresis, euphoria, and paranoia or psychosis. This contrasts sharply with the opioid toxidrome of miosis and respiratory depression and the sedative toxidrome of CNS depression with normal pupils.
- A 34-year-old woman with opioid use disorder is being started on maintenance therapy. She is offered a partial mu-opioid agonist often combined with naloxone to deter misuse. Which medication is this?
- Methadone
- Buprenorphine
- Naltrexone
- Clonidine
Correct answer: Buprenorphine
Buprenorphine is the partial mu-opioid agonist described. It is used for opioid use disorder maintenance, often co-formulated with naloxone to discourage injection misuse, and its partial agonism gives a ceiling effect that lowers overdose risk. Methadone is a full agonist alternative, and naltrexone is an opioid antagonist used after detoxification to block opioid effects.
- A 50-year-old man with a long history of heavy alcohol use presents with confusion, gait ataxia, and ophthalmoplegia. Which deficiency underlies this acute, reversible encephalopathy, and what is the immediate treatment?
- Vitamin B12 deficiency, treated with oral B12
- Folate deficiency, treated with folic acid
- Thiamine deficiency, treated with parenteral thiamine before glucose
- Niacin deficiency, treated with niacin
Correct answer: Thiamine deficiency, treated with parenteral thiamine before glucose
Thiamine deficiency underlies Wernicke encephalopathy and requires parenteral thiamine before glucose. The classic triad is confusion, ataxia, and ophthalmoplegia or nystagmus, and prompt thiamine repletion can reverse it; giving glucose first can precipitate or worsen the syndrome. Untreated cases may progress to the irreversible memory impairment and confabulation of Korsakoff syndrome.
- A 22-year-old man with schizophrenia has had inadequate response to two adequate trials of different antipsychotics. The clinician considers the one antipsychotic with proven superior efficacy for treatment-resistant schizophrenia. Which agent is this, and what serious adverse effect mandates regular monitoring?
- Haloperidol, which requires monitoring for tardive dyskinesia only
- Risperidone, which requires monitoring of prolactin
- Aripiprazole, which requires monitoring for weight gain
- Clozapine, which requires monitoring of the absolute neutrophil count for agranulocytosis
Correct answer: Clozapine, which requires monitoring of the absolute neutrophil count for agranulocytosis
Clozapine is the agent, and it requires regular absolute neutrophil count monitoring. Clozapine is uniquely effective for treatment-resistant schizophrenia and reduces suicidality, but it can cause life-threatening agranulocytosis, so the absolute neutrophil count must be checked on a scheduled basis. It also carries risks of seizures, myocarditis, and metabolic effects, which is why it is reserved for refractory cases.
- A 36-year-old man with bipolar I disorder presents in an acute manic episode with psychotic features and severe agitation requiring rapid control. Which pharmacologic approach is most appropriate for acute mania?
- A mood stabilizer such as lithium or valproate, often combined with a second-generation antipsychotic
- An SSRI started immediately as monotherapy
- A stimulant to improve concentration
- A benzodiazepine alone as definitive long-term therapy
Correct answer: A mood stabilizer such as lithium or valproate, often combined with a second-generation antipsychotic
A mood stabilizer combined with a second-generation antipsychotic is most appropriate for acute mania. Lithium or valproate provides core mood stabilization, and an antipsychotic such as olanzapine or quetiapine controls psychosis and agitation more rapidly; a benzodiazepine may be added short-term for severe agitation. Antidepressants are avoided in acute mania because they can worsen the episode.
- A 70-year-old man with a 50-pack-year smoking history presents with three weeks of productive cough, fever, and right-sided chest pain. A chest radiograph shows a right lower lobe infiltrate, and on examination there is dullness to percussion, increased tactile fremitus, and bronchial breath sounds over the area. Which pathophysiologic change best explains the increased tactile fremitus and bronchial breath sounds in this region?
- Consolidation of alveoli with fluid that improves transmission of sound from the airways
- Air trapping that hyperinflates the affected lobe
- Accumulation of pleural fluid that dampens sound transmission
- Loss of lung volume from bronchial obstruction
Correct answer: Consolidation of alveoli with fluid that improves transmission of sound from the airways
Consolidation of the alveoli with inflammatory fluid is the correct explanation. When alveoli fill with exudate, the denser fluid-filled lung transmits sound from the larger airways far better than normal air-filled lung, producing increased tactile fremitus, bronchial breath sounds, and dullness to percussion. Air trapping and hyperinflation cause hyperresonance and decreased breath sounds, pleural fluid decreases fremitus, and lobar collapse from obstruction reduces rather than enhances sound transmission.
- A 58-year-old woman presents to the emergency department with fever, productive cough, and dyspnea. Her respiratory rate is 32, she is confused, her blood urea nitrogen is elevated, and her blood pressure is 88/56 mm Hg. Using the CURB-65 criteria, how many points does she have and what is the most appropriate disposition?
- One point, manage as an outpatient
- Four points, admit with consideration of intensive care
- Two points, brief inpatient observation
- Zero points, no further evaluation needed
Correct answer: Four points, admit with consideration of intensive care
Four points warranting admission and intensive care consideration is correct. CURB-65 assigns one point each for Confusion, Urea elevation, Respiratory rate of 30 or higher, low Blood pressure (systolic below 90 or diastolic 60 or lower), and age 65 or older. This patient meets confusion, urea, respiratory rate, and blood pressure for four points, which indicates high mortality risk and need for hospitalization with possible ICU care. The lower point totals understate her severity.
- A healthy 35-year-old presents with several days of low-grade fever, malaise, headache, and a persistent nonproductive cough. The chest radiograph shows patchy bilateral interstitial infiltrates that appear far worse than the relatively mild physical examination findings. Which organism is the most likely cause of this atypical pneumonia?
- Mycoplasma pneumoniae
- Streptococcus pneumoniae
- Staphylococcus aureus
- Klebsiella pneumoniae
Correct answer: Mycoplasma pneumoniae
Mycoplasma pneumoniae is the correct answer. It classically causes atypical or walking pneumonia in younger patients, with a gradual onset of dry cough, constitutional symptoms, and chest radiograph findings that look worse than the patient appears clinically. Streptococcus pneumoniae produces a typical lobar pneumonia with rust-colored sputum, Staphylococcus aureus often follows influenza with severe disease, and Klebsiella causes a severe necrotizing pneumonia with currant-jelly sputum in alcoholics.
- A 50-year-old man being treated empirically for community-acquired pneumonia has sputum cultures that grow gram-negative rods, and he reports recent exposure to a contaminated air conditioning cooling system. He also has diarrhea, confusion, and hyponatremia. Which pathogen and which laboratory test best fit this presentation?
- Mycoplasma pneumoniae, cold agglutinins
- Streptococcus pneumoniae, blood culture
- Legionella pneumophila, urinary antigen test
- Pseudomonas aeruginosa, sputum Gram stain
Correct answer: Legionella pneumophila, urinary antigen test
Legionella pneumophila with a urinary antigen test is correct. Legionella is associated with water sources such as cooling towers and is classically accompanied by gastrointestinal symptoms, confusion, and hyponatremia. The urinary antigen test is the rapid diagnostic test of choice for the most common serogroup. The other pairings do not match the extrapulmonary findings or the water exposure history that characterize Legionella infection.
- A 62-year-old man with a long smoking history reports daily productive cough for the past four years, occurring on most days for at least three consecutive months in each of the past two years. He has no other identifiable cause for the cough. Which diagnosis does this clinical history define?
- Asthma
- Emphysema
- Chronic bronchitis
- Bronchiectasis
Correct answer: Chronic bronchitis
Chronic bronchitis is the correct diagnosis. It is defined clinically as a productive cough for at least three months in each of two consecutive years in the absence of another explanation. Emphysema is defined pathologically by destruction of alveolar walls, asthma involves reversible airflow obstruction with hyperresponsiveness, and bronchiectasis involves permanent abnormal dilation of bronchi with copious purulent sputum.
- A 68-year-old man with chronic obstructive pulmonary disease undergoes spirometry. Which spirometric finding is required to confirm the presence of persistent airflow obstruction?
- A total lung capacity below the lower limit of normal
- A post-bronchodilator FEV1/FVC ratio below 0.70
- An FEV1/FVC ratio above 0.80
- A normal FEV1 with a reduced FVC
Correct answer: A post-bronchodilator FEV1/FVC ratio below 0.70
A post-bronchodilator FEV1/FVC ratio below 0.70 is correct. This fixed ratio confirms persistent, not fully reversible airflow limitation, which is the hallmark of chronic obstructive pulmonary disease. A reduced total lung capacity suggests a restrictive process, a ratio above 0.80 is normal or restrictive, and a normal ratio with reduced FVC points toward restriction rather than obstruction.
- A 72-year-old man with severe chronic obstructive pulmonary disease has stable disease, and his resting arterial oxygen partial pressure on room air is 52 mm Hg. Which intervention has been shown to improve survival in patients with this degree of chronic hypoxemia?
- Long-term oral corticosteroids
- Long-term continuous supplemental oxygen therapy
- Chronic prophylactic antibiotics
- Routine theophylline therapy
Correct answer: Long-term continuous supplemental oxygen therapy
Long-term continuous supplemental oxygen therapy is correct. In chronic obstructive pulmonary disease patients with severe resting hypoxemia, defined as an arterial oxygen partial pressure of 55 mm Hg or lower (or 59 or lower with cor pulmonale or polycythemia), continuous oxygen reduces mortality. Long-term oral corticosteroids carry significant harms, chronic antibiotics are reserved for select frequent exacerbators, and theophylline has not been shown to improve survival.
- A 65-year-old woman with chronic obstructive pulmonary disease presents with an acute exacerbation characterized by increased dyspnea, increased sputum volume, and increased sputum purulence. In addition to bronchodilators and oxygen, which two therapies are most appropriate to initiate?
- Inhaled corticosteroids alone
- Inhaled long-acting bronchodilators only
- Diuretics and intravenous fluids
- Systemic corticosteroids and antibiotics
Correct answer: Systemic corticosteroids and antibiotics
Systemic corticosteroids and antibiotics is correct. An exacerbation marked by all three cardinal features (increased dyspnea, sputum volume, and sputum purulence) warrants antibiotics, and a short course of systemic corticosteroids shortens recovery and reduces relapse. Long-acting bronchodilators alone are insufficient acutely, diuretics treat volume overload not airflow obstruction, and inhaled corticosteroids alone do not address the acute exacerbation.
- A 23-year-old woman with asthma arrives in the emergency department in severe distress, using accessory muscles, with a peak expiratory flow that is 40 percent of predicted and oxygen saturation of 90 percent. After oxygen, which combination of medications represents the most appropriate immediate pharmacologic treatment?
- Inhaled long-acting beta-agonist alone
- Inhaled short-acting beta-agonist plus inhaled ipratropium and systemic corticosteroids
- Oral leukotriene receptor antagonist alone
- Inhaled corticosteroid monotherapy
Correct answer: Inhaled short-acting beta-agonist plus inhaled ipratropium and systemic corticosteroids
Inhaled short-acting beta-agonist plus ipratropium and systemic corticosteroids is correct. Severe asthma exacerbations are treated with repeated short-acting beta-agonists, an inhaled anticholinergic for added bronchodilation, and early systemic corticosteroids to reduce airway inflammation. Long-acting beta-agonists are not used as rescue therapy, and leukotriene antagonists and inhaled corticosteroid monotherapy have no role in acute severe exacerbations.
- A 30-year-old man with persistent asthma uses his short-acting beta-agonist inhaler more than twice weekly and awakens at night with symptoms several times a month despite no controller medication. According to current stepwise management, which controller therapy should be added?
- A low-dose inhaled corticosteroid
- A short-acting beta-agonist scheduled four times daily
- Oral corticosteroids daily
- No controller is needed
Correct answer: A low-dose inhaled corticosteroid
A low-dose inhaled corticosteroid is correct. When asthma is no longer intermittent, the foundational controller is an inhaled corticosteroid, which targets the underlying airway inflammation. Scheduling a short-acting beta-agonist does not control inflammation and signals poor control, daily oral corticosteroids are reserved for severe refractory disease, and withholding a controller leaves persistent asthma untreated.
- A 27-year-old woman in the emergency department for a severe asthma exacerbation has received repeated albuterol and corticosteroids but remains in distress. Her initial arterial blood gas showed respiratory alkalosis, but a repeat now shows a normal partial pressure of carbon dioxide. How should this normalizing carbon dioxide be interpreted?
- An expected response to bronchodilators indicating discharge readiness
- Reassuring evidence of full recovery
- Evidence of metabolic compensation that needs no action
- A warning sign of impending respiratory failure from fatigue
Correct answer: A warning sign of impending respiratory failure from fatigue
A warning sign of impending respiratory failure is correct. In a severe asthma exacerbation, tachypnea initially produces a low carbon dioxide and respiratory alkalosis. A normalizing or rising carbon dioxide in a patient still in distress indicates the patient is tiring and can no longer maintain adequate ventilation, signaling impending respiratory failure and the possible need for intubation. It is not reassuring, compensatory, or a sign of readiness for discharge.
- A 26-year-old woman with no chronic medical conditions develops sudden pleuritic chest pain and dyspnea two weeks after knee surgery, and she has unilateral leg swelling. Using clinical decision-making, which initial test is most appropriate to confirm or exclude pulmonary embolism in a hemodynamically stable patient with a high pretest probability?
- D-dimer assay
- CT pulmonary angiography
- Chest radiograph
- Arterial blood gas
Correct answer: CT pulmonary angiography
CT pulmonary angiography is correct. In a hemodynamically stable patient with a high clinical pretest probability of pulmonary embolism, imaging with CT pulmonary angiography is the test of choice because a D-dimer is unhelpful when probability is already high. A chest radiograph and arterial blood gas may be supportive but cannot confirm or exclude the diagnosis. D-dimer is best reserved for patients with low or intermediate pretest probability.
- A 55-year-old man presents with acute dyspnea and pleuritic chest pain. He is hypotensive with a systolic blood pressure of 78 mm Hg, and CT angiography confirms a large saddle pulmonary embolism with right ventricular strain. What is the most appropriate treatment for this hemodynamically unstable patient?
- An inferior vena cava filter as monotherapy
- Oral apixaban alone
- Systemic thrombolytic therapy
- Outpatient low-molecular-weight heparin
Correct answer: Systemic thrombolytic therapy
Systemic thrombolytic therapy is correct. A massive pulmonary embolism causing hemodynamic instability is an indication for thrombolysis to rapidly dissolve the clot and restore pulmonary perfusion, in the absence of contraindications. Anticoagulation alone is insufficient for an unstable patient, an inferior vena cava filter does not treat the existing clot, and outpatient management is inappropriate for hemodynamic instability.
- A 48-year-old woman with a suspected pulmonary embolism has an electrocardiogram performed. Which classic but uncommon electrocardiographic pattern, when present, would support the diagnosis of acute right heart strain from pulmonary embolism?
- An S wave in lead I, a Q wave in lead III, and an inverted T wave in lead III
- Diffuse concave ST-segment elevation
- A delta wave with a short PR interval
- Tall peaked T waves across the precordial leads
Correct answer: An S wave in lead I, a Q wave in lead III, and an inverted T wave in lead III
The S1Q3T3 pattern is correct. This classic but infrequent finding reflects acute right ventricular strain and supports pulmonary embolism, although sinus tachycardia is the most common abnormality. Diffuse concave ST elevation suggests pericarditis, a delta wave with short PR indicates pre-excitation, and tall peaked T waves suggest hyperkalemia, none of which point to pulmonary embolism.
- A 22-year-old tall, thin man develops sudden right-sided pleuritic chest pain and dyspnea at rest. On examination he has decreased breath sounds and hyperresonance to percussion on the right, and he is hemodynamically stable. What is the most likely diagnosis?
- Tension pneumothorax
- Primary spontaneous pneumothorax
- Massive pleural effusion
- Lobar pneumonia
Correct answer: Primary spontaneous pneumothorax
Primary spontaneous pneumothorax is correct. Tall, thin young men are at characteristic risk, and the sudden pleuritic pain, dyspnea, decreased breath sounds, and hyperresonance with hemodynamic stability fit a simple spontaneous pneumothorax. A tension pneumothorax would cause hemodynamic compromise and tracheal deviation, a pleural effusion produces dullness rather than hyperresonance, and pneumonia produces dullness with increased fremitus.
- A trauma patient is in severe respiratory distress with hypotension, distended neck veins, absent breath sounds on the left, and tracheal deviation to the right. What is the most appropriate immediate intervention?
- Immediate needle decompression of the left chest
- Obtain a chest radiograph before any treatment
- Administer a fluid bolus and reassess
- Start noninvasive positive pressure ventilation
Correct answer: Immediate needle decompression of the left chest
Immediate needle decompression of the affected chest is correct. A tension pneumothorax is a clinical diagnosis, and the combination of distress, hypotension, distended neck veins, absent breath sounds, and tracheal deviation away from the affected side demands emergent decompression without waiting for imaging. Obtaining a radiograph first wastes critical time, fluids do not address the trapped air, and positive pressure ventilation can worsen the tension.
- A 38-year-old woman develops acute hypoxemic respiratory failure two days after the onset of severe pancreatitis. Chest radiograph shows bilateral diffuse infiltrates, her ratio of arterial oxygen to inspired oxygen fraction is 150, and there is no evidence of heart failure. Which diagnosis best fits these findings?
- Lobar pneumonia
- Cardiogenic pulmonary edema
- Pulmonary embolism
- Acute respiratory distress syndrome
Correct answer: Acute respiratory distress syndrome
Acute respiratory distress syndrome is correct. It is defined by acute onset within one week of an insult, bilateral infiltrates not fully explained by cardiac failure, and impaired oxygenation reflected by a low ratio of arterial oxygen to inspired oxygen fraction. Cardiogenic edema is excluded by the absence of heart failure, pulmonary embolism does not typically cause diffuse bilateral infiltrates, and lobar pneumonia is focal rather than diffuse.
- A patient with acute respiratory distress syndrome requires mechanical ventilation. Which ventilation strategy has been shown to reduce mortality in this condition?
- High tidal volume ventilation to maximize oxygenation
- Low tidal volume lung-protective ventilation
- Routine use of high inspiratory plateau pressures
- Permissive hyperoxia with very high oxygen targets
Correct answer: Low tidal volume lung-protective ventilation
Low tidal volume lung-protective ventilation is correct. Using low tidal volumes (about 6 milliliters per kilogram of predicted body weight) and limiting plateau pressures reduces ventilator-induced lung injury and improves survival in acute respiratory distress syndrome. High tidal volumes and high plateau pressures cause barotrauma and volutrauma, and excessive oxygen targets risk oxygen toxicity without survival benefit.
- A 54-year-old obese man reports loud snoring, witnessed apneic pauses during sleep reported by his partner, morning headaches, and severe daytime sleepiness. Which test is the gold standard for confirming the suspected diagnosis?
- Chest computed tomography
- Pulmonary function testing
- Arterial blood gas analysis
- In-laboratory polysomnography
Correct answer: In-laboratory polysomnography
In-laboratory polysomnography is correct. The clinical picture suggests obstructive sleep apnea, and an overnight sleep study quantifying the apnea-hypopnea index is the diagnostic gold standard. Pulmonary function testing assesses airflow obstruction or restriction, arterial blood gases assess gas exchange, and chest computed tomography evaluates parenchymal disease, none of which establish the diagnosis of sleep apnea.
- A 49-year-old man is diagnosed with moderate-to-severe obstructive sleep apnea. Besides recommending weight loss, which therapy is the most effective first-line treatment?
- Daily inhaled corticosteroids
- Supplemental nighttime oxygen alone
- A nightly sedative-hypnotic
- Continuous positive airway pressure
Correct answer: Continuous positive airway pressure
Continuous positive airway pressure is correct. It is the most effective first-line therapy for moderate-to-severe obstructive sleep apnea because it pneumatically splints the upper airway open during sleep. Supplemental oxygen alone does not prevent the obstructive events, sedative-hypnotics worsen apnea by relaxing the airway, and inhaled corticosteroids treat airway inflammation in asthma, not the mechanical obstruction of sleep apnea.
- A 61-year-old man has progressive dyspnea, and examination reveals dullness to percussion, decreased breath sounds, and decreased tactile fremitus over the right lung base. After confirming a pleural effusion, thoracentesis fluid is analyzed and meets one of Light criteria with a pleural-to-serum protein ratio greater than 0.5. How should this effusion be classified?
- A chylous effusion
- A transudative effusion
- An exudative effusion
- A hemothorax
Correct answer: An exudative effusion
An exudative effusion is correct. By Light criteria, an effusion is exudative if any one criterion is met, including a pleural-to-serum protein ratio greater than 0.5, indicating increased capillary permeability or pleural disease such as infection or malignancy. Transudates result from systemic factors like heart failure, a chylous effusion contains chylomicrons with high triglycerides, and a hemothorax is blood in the pleural space.
- A 65-year-old man with community-acquired pneumonia worsens despite antibiotics and develops a parapneumonic effusion. Thoracentesis reveals pleural fluid with a pH of 7.1, low glucose, and frank pus. What is the most appropriate next step in management?
- Continued observation with antibiotics alone
- Tube thoracostomy drainage
- Diuretic therapy
- Repeat thoracentesis in one week
Correct answer: Tube thoracostomy drainage
Tube thoracostomy drainage is correct. A complicated parapneumonic effusion or empyema, indicated by a low pleural pH, low glucose, and frank pus, requires drainage with a chest tube in addition to antibiotics. Antibiotics alone will not clear infected loculated fluid, diuretics treat transudative effusions of heart failure, and delaying with repeat thoracentesis risks worsening sepsis and loculation.
- A 33-year-old African American woman presents with cough, dyspnea, and tender red nodules on her shins. A chest radiograph shows bilateral hilar lymphadenopathy. Which biopsy finding would confirm the most likely diagnosis?
- Ferruginous bodies
- Caseating granulomas with acid-fast bacilli
- Reed-Sternberg cells
- Noncaseating granulomas
Correct answer: Noncaseating granulomas
Noncaseating granulomas are correct. The combination of bilateral hilar lymphadenopathy, erythema nodosum, and pulmonary symptoms in a young African American woman strongly suggests sarcoidosis, which is confirmed by noncaseating granulomas on biopsy. Caseating granulomas with acid-fast bacilli indicate tuberculosis, Reed-Sternberg cells indicate Hodgkin lymphoma, and ferruginous bodies indicate asbestosis.
- A 40-year-old woman with biopsy-proven pulmonary sarcoidosis has progressive symptomatic disease with declining lung function. Which medication is the first-line treatment for symptomatic pulmonary sarcoidosis?
- Inhaled short-acting beta-agonists
- Systemic corticosteroids
- Broad-spectrum antibiotics
- Loop diuretics
Correct answer: Systemic corticosteroids
Systemic corticosteroids are correct. They are the mainstay of therapy for symptomatic or progressive pulmonary sarcoidosis because they suppress the granulomatous inflammation. Short-acting beta-agonists relieve bronchospasm but do not treat the underlying granulomatous process, antibiotics are not indicated for this noninfectious disease, and diuretics have no role in treating sarcoidosis.
- A patient with sarcoidosis is found to have hypercalcemia. Which mechanism best explains the elevated serum calcium in this disease?
- Excess secretion of parathyroid hormone from the parathyroid glands
- Increased conversion of vitamin D to its active form by activated macrophages in granulomas
- Bony metastases releasing calcium
- Decreased renal excretion from intrinsic kidney disease
Correct answer: Increased conversion of vitamin D to its active form by activated macrophages in granulomas
Increased conversion of vitamin D by granuloma macrophages is correct. In sarcoidosis, activated macrophages within granulomas express the enzyme that converts vitamin D to its active 1,25-dihydroxy form, increasing intestinal calcium absorption and causing hypercalcemia. Parathyroid hormone is suppressed rather than elevated, the disease is not metastatic, and the mechanism is increased absorption rather than impaired renal excretion.
- A 68-year-old man with a long smoking history presents with progressive exertional dyspnea and a dry cough over a year. Examination reveals fine bibasilar inspiratory crackles and digital clubbing, and high-resolution CT shows peripheral subpleural reticular opacities with honeycombing. Which diagnosis best fits?
- Acute eosinophilic pneumonia
- Chronic obstructive pulmonary disease
- Asthma
- Idiopathic pulmonary fibrosis
Correct answer: Idiopathic pulmonary fibrosis
Idiopathic pulmonary fibrosis is correct. The insidious progressive dyspnea, dry cough, fine bibasilar crackles, clubbing, and a CT pattern of subpleural reticulation with honeycombing are characteristic of this progressive fibrosing interstitial lung disease. Chronic obstructive pulmonary disease causes airflow obstruction and hyperinflation, asthma is reversible and episodic, and acute eosinophilic pneumonia presents acutely with eosinophilia rather than chronic fibrosis.
- A 60-year-old man who worked for 30 years insulating pipes in shipyards presents with progressive dyspnea. Imaging shows bilateral pleural plaques and lower-lobe interstitial fibrosis. Exposure to which agent is most strongly associated with these findings and with a markedly increased risk of mesothelioma?
- Beryllium
- Coal dust
- Silica
- Asbestos
Correct answer: Asbestos
Asbestos is correct. Asbestos exposure, common in shipyard insulation work, classically produces bilateral pleural plaques and lower-lobe interstitial fibrosis (asbestosis) and dramatically raises the risk of mesothelioma and bronchogenic carcinoma. Coal dust causes coal workers pneumoconiosis, silica exposure causes silicosis with upper-lobe nodules, and beryllium causes a granulomatous lung disease, none of which cause the pleural plaques and mesothelioma association of asbestos.
- A 46-year-old farmer presents with recurrent episodes of fever, cough, and dyspnea that begin several hours after he works with moldy hay and resolve when he is away from the farm. Which is the most likely diagnosis?
- Community-acquired pneumonia
- Allergic asthma
- Hypersensitivity pneumonitis
- Chronic obstructive pulmonary disease
Correct answer: Hypersensitivity pneumonitis
Hypersensitivity pneumonitis is correct. This immune-mediated interstitial lung disease results from repeated inhalation of an organic antigen such as the thermophilic actinomycetes in moldy hay (farmer's lung), producing recurrent flu-like respiratory symptoms hours after exposure that improve with avoidance. Allergic asthma causes wheezing and reversible obstruction, pneumonia is an acute infection, and chronic obstructive pulmonary disease is a fixed obstructive process unrelated to specific antigen exposure.
- A 71-year-old man with a heavy smoking history presents with cough, hemoptysis, and weight loss, and is found to have a central lung mass. Laboratory studies show a markedly low serum sodium with an inappropriately concentrated urine. Which lung cancer subtype is most associated with this paraneoplastic syndrome?
- Adenocarcinoma
- Squamous cell carcinoma
- Small cell lung carcinoma
- Bronchioloalveolar carcinoma
Correct answer: Small cell lung carcinoma
Small cell lung carcinoma is correct. This central tumor is strongly associated with paraneoplastic syndromes including the syndrome of inappropriate antidiuretic hormone secretion, which causes hyponatremia with inappropriately concentrated urine. Squamous cell carcinoma is associated with hypercalcemia from parathyroid hormone-related peptide, while adenocarcinoma is typically peripheral and less associated with this particular endocrine syndrome.
- A 70-year-old smoker is found to have squamous cell carcinoma of the lung. Which paraneoplastic laboratory abnormality is most characteristically associated with this histologic subtype?
- Hyponatremia from antidiuretic hormone excess
- Hypercalcemia from parathyroid hormone-related peptide
- Cushing syndrome from ectopic ACTH
- Hypoglycemia from insulin-like growth factor
Correct answer: Hypercalcemia from parathyroid hormone-related peptide
Hypercalcemia from parathyroid hormone-related peptide is correct. Squamous cell carcinoma of the lung classically secretes parathyroid hormone-related peptide, producing hypercalcemia. Antidiuretic hormone excess causing hyponatremia and ectopic ACTH causing Cushing syndrome are associated with small cell carcinoma, and insulin-like growth factor hypoglycemia is more typical of other tumors, not squamous cell lung cancer.
- A 64-year-old asymptomatic former smoker has a chest CT that incidentally shows a solitary 6 mm solid pulmonary nodule with smooth, well-defined margins. What is the most appropriate next step in management?
- Surveillance with a follow-up CT scan
- Immediate surgical resection
- Immediate chemotherapy
- Reassurance with no further imaging
Correct answer: Surveillance with a follow-up CT scan
Surveillance with a follow-up CT is correct. A small solid nodule with benign-appearing smooth margins in a patient with risk factors is managed with interval imaging to assess for growth rather than immediate intervention. Surgical resection and chemotherapy are inappropriate for an indeterminate small nodule without a tissue diagnosis, and given the patient's smoking history, ignoring it entirely is unsafe.
- A 5-month-old infant presents in winter with two days of rhinorrhea progressing to wheezing, tachypnea, nasal flaring, and intercostal retractions. Which pathogen is the most common cause of this lower respiratory tract illness in infants?
- Parainfluenza virus
- Streptococcus pneumoniae
- Respiratory syncytial virus
- Bordetella pertussis
Correct answer: Respiratory syncytial virus
Respiratory syncytial virus is correct. It is the most common cause of bronchiolitis, which presents in infants during the winter with an upper respiratory prodrome progressing to wheezing, tachypnea, and respiratory distress. Streptococcus pneumoniae causes bacterial pneumonia, parainfluenza most commonly causes croup, and Bordetella pertussis causes whooping cough with paroxysms rather than diffuse wheezing.
- A 2-year-old presents in autumn with a barking, seal-like cough, inspiratory stridor, and hoarseness, and a frontal neck radiograph shows subglottic narrowing. Which radiographic sign and treatment are most appropriate?
- Air bronchograms; oral amoxicillin
- Thumbprint sign; emergent airway and antibiotics
- Sail sign; observation only
- Steeple sign; corticosteroids and nebulized epinephrine for stridor at rest
Correct answer: Steeple sign; corticosteroids and nebulized epinephrine for stridor at rest
Steeple sign with corticosteroids and nebulized epinephrine is correct. Croup, usually caused by parainfluenza virus, produces a barking cough and subglottic narrowing seen as the steeple sign, and is treated with corticosteroids, plus nebulized epinephrine when there is stridor at rest. The thumbprint sign indicates epiglottitis, the sail sign refers to a normal thymus, and air bronchograms with amoxicillin point toward bacterial pneumonia.
- A previously healthy 28-year-old presents with an acute cough productive of clear sputum that began with an upper respiratory infection and has lasted one week. There is no fever, no tachypnea, and the chest is clear with a normal radiograph. What is the most appropriate management?
- Inhaled tobramycin
- Empiric broad-spectrum antibiotics
- Systemic corticosteroids
- Supportive care without antibiotics
Correct answer: Supportive care without antibiotics
Supportive care without antibiotics is correct. Acute bronchitis is almost always viral and is self-limited, so management focuses on symptom relief rather than antibiotics, which provide no benefit and promote resistance. Systemic corticosteroids are not routinely indicated, and inhaled tobramycin is used for chronic Pseudomonas infection in conditions such as cystic fibrosis, not acute viral bronchitis.
- A 4-month-old unvaccinated infant has had two weeks of severe coughing fits, some ending in an inspiratory whoop and posttussive emesis, with relatively normal findings between episodes. Which antibiotic is the most appropriate treatment for the suspected infection?
- Vancomycin
- Amoxicillin
- A macrolide such as azithromycin
- Doxycycline
Correct answer: A macrolide such as azithromycin
A macrolide such as azithromycin is correct. The paroxysmal cough with inspiratory whoop and posttussive emesis in an unvaccinated child is classic for pertussis caused by Bordetella pertussis, and macrolides are the treatment of choice. Amoxicillin is not effective against Bordetella, vancomycin targets gram-positive cocci, and doxycycline is avoided in young children due to dental effects.
- A 50-year-old woman with a history of recurrent childhood respiratory infections has chronic daily cough producing large volumes of purulent sputum, with intermittent hemoptysis. High-resolution CT shows permanently dilated, thickened bronchi with a tram-track appearance. What is the diagnosis?
- Bronchiectasis
- Chronic bronchitis
- Emphysema
- Asthma
Correct answer: Bronchiectasis
Bronchiectasis is correct. It is defined by permanent abnormal dilation of the bronchi, producing chronic copious purulent sputum, recurrent infections, hemoptysis, and characteristic tram-track or signet-ring findings on CT. Chronic bronchitis lacks the structural bronchial dilation, emphysema involves alveolar destruction with hyperinflation, and asthma features reversible airflow obstruction without permanent bronchial dilation.
- A 3-year-old develops sudden coughing, choking, and unilateral wheezing immediately after playing with small toys. He is stable, and a chest radiograph shows hyperinflation of the right lung that worsens on expiration. What is the most appropriate definitive step?
- Rigid bronchoscopy to remove the object
- Reassurance and discharge
- A trial of inhaled bronchodilators
- Empiric antibiotics for pneumonia
Correct answer: Rigid bronchoscopy to remove the object
Rigid bronchoscopy is correct. The sudden choking with unilateral wheezing and air trapping on expiratory films indicates a foreign body aspiration lodged in a bronchus, and bronchoscopy is both diagnostic and therapeutic for removal. Discharge risks complications, bronchodilators will not relieve a mechanical obstruction, and antibiotics do not address the retained foreign body.
- A 3-week-old infant has failure to thrive, recurrent respiratory infections, and greasy foul-smelling stools. The diagnostic study reveals an elevated sweat chloride concentration. Which is the underlying defect responsible for this disease?
- A defect in ciliary dynein arms
- A deficiency of alpha-1 antitrypsin
- A mutation in the chloride channel encoded by the CFTR gene
- An autoimmune attack on exocrine glands
Correct answer: A mutation in the chloride channel encoded by the CFTR gene
A mutation in the CFTR chloride channel is correct. Cystic fibrosis results from mutations in the cystic fibrosis transmembrane conductance regulator gene, impairing chloride transport and producing thick secretions that cause recurrent lung infections, pancreatic insufficiency with steatorrhea, and an elevated sweat chloride. Alpha-1 antitrypsin deficiency causes emphysema, dynein arm defects cause primary ciliary dyskinesia, and autoimmune exocrine destruction describes Sjogren syndrome.
- A 42-year-old lifelong nonsmoker presents with dyspnea and is found to have early-onset emphysema predominantly affecting the lung bases, along with abnormal liver function tests. Which deficiency best explains this combination of findings?
- Iron deficiency
- Surfactant deficiency
- Vitamin D deficiency
- Alpha-1 antitrypsin deficiency
Correct answer: Alpha-1 antitrypsin deficiency
Alpha-1 antitrypsin deficiency is correct. This inherited disorder leads to unopposed protease activity causing early-onset panacinar emphysema, classically in the lower lobes and in nonsmokers, and the abnormal protein accumulates in the liver causing hepatic dysfunction. Surfactant deficiency causes neonatal respiratory distress, while vitamin D and iron deficiencies do not produce emphysema with liver involvement.
- A 58-year-old woman with longstanding severe chronic lung disease and chronic hypoxemia develops lower-extremity edema, an elevated jugular venous pressure, and a loud pulmonic component of the second heart sound. Which condition has developed?
- Constrictive pericarditis
- Left-sided systolic heart failure
- Cor pulmonale
- Aortic stenosis
Correct answer: Cor pulmonale
Cor pulmonale is correct. It refers to right ventricular enlargement and eventual failure caused by chronic lung disease and pulmonary hypertension, producing signs of right heart strain such as peripheral edema, elevated jugular venous pressure, and an accentuated pulmonic second heart sound. Left-sided heart failure originates from cardiac rather than pulmonary disease, and constrictive pericarditis and aortic stenosis have different mechanisms and findings.
- A 47-year-old woman has progressive exertional dyspnea and fatigue. She has no left heart disease, chronic lung disease, or thromboembolism, and right heart catheterization confirms an elevated mean pulmonary artery pressure. Which diagnosis does this represent?
- Chronic obstructive pulmonary disease
- Cardiogenic pulmonary edema
- Pulmonary arterial hypertension
- Recurrent pulmonary embolism
Correct answer: Pulmonary arterial hypertension
Pulmonary arterial hypertension is correct. When elevated pulmonary artery pressure is confirmed by right heart catheterization in the absence of left heart disease, lung disease, or chronic thromboembolism, the diagnosis is pulmonary arterial hypertension. Cardiogenic edema arises from left heart disease, chronic obstructive pulmonary disease causes airflow obstruction, and recurrent embolism is excluded by the absence of thromboembolic disease.
- A postoperative patient on the second day after upper abdominal surgery develops low-grade fever, mild hypoxemia, and decreased breath sounds at both bases. A chest radiograph shows volume loss at the lung bases. What is the most likely cause?
- Aspiration pneumonia
- Pulmonary embolism
- Atelectasis
- Pneumothorax
Correct answer: Atelectasis
Atelectasis is correct. Postoperative atelectasis from shallow breathing and retained secretions is the most common cause of fever and hypoxemia in the first 48 hours after surgery, producing basal volume loss and decreased breath sounds. Pulmonary embolism typically presents with pleuritic pain and tachycardia, aspiration pneumonia produces infiltrates, and pneumothorax causes hyperresonance and absent breath sounds rather than volume loss.
- A 26-year-old woman is brought in after an opioid overdose with profound somnolence and shallow, slow breathing. Her arterial blood gas shows a pH of 7.22, a partial pressure of carbon dioxide of 70 mm Hg, and a normal bicarbonate. Which acid-base disorder is present?
- Acute respiratory acidosis
- Acute respiratory alkalosis
- Metabolic acidosis
- Metabolic alkalosis
Correct answer: Acute respiratory acidosis
Acute respiratory acidosis is correct. Opioid-induced hypoventilation causes carbon dioxide retention, raising the partial pressure of carbon dioxide and lowering the pH, with a normal bicarbonate indicating an acute, uncompensated respiratory process. Respiratory alkalosis would show a low carbon dioxide, and metabolic disorders would manifest primarily through bicarbonate changes rather than carbon dioxide elevation.
- A 36-year-old anxious woman presents with acute dyspnea, perioral and digital tingling, and lightheadedness after an argument. Her arterial blood gas shows a pH of 7.52 and a low partial pressure of carbon dioxide. Which acid-base disorder explains her symptoms?
- Metabolic alkalosis
- Acute respiratory acidosis
- Anion gap metabolic acidosis
- Acute respiratory alkalosis
Correct answer: Acute respiratory alkalosis
Acute respiratory alkalosis is correct. Anxiety-driven hyperventilation lowers the partial pressure of carbon dioxide and raises the pH, and the resulting alkalosis decreases ionized calcium, producing the perioral and digital paresthesias and lightheadedness. Respiratory acidosis involves carbon dioxide retention, and the metabolic disorders are driven by bicarbonate changes rather than the primary hyperventilation seen here.
- A pulmonary function test is performed on a 60-year-old patient. The FEV1 is reduced, the FVC is reduced proportionally, the FEV1/FVC ratio is normal or increased, and the total lung capacity is reduced. Which pattern do these findings represent?
- An obstructive ventilatory defect
- A restrictive ventilatory defect
- A mixed defect with air trapping
- A normal study
Correct answer: A restrictive ventilatory defect
A restrictive ventilatory defect is correct. Restriction is characterized by a reduced total lung capacity with proportionally reduced FEV1 and FVC and a preserved or increased FEV1/FVC ratio, as seen in interstitial lung disease or chest wall disorders. An obstructive pattern shows a reduced FEV1/FVC ratio, and the proportional volume reduction with normal ratio rules out a purely obstructive or normal study.
- A 55-year-old man with progressive dyspnea has spirometry showing airflow obstruction, and a measurement of how efficiently gases cross the alveolar-capillary membrane is markedly reduced. A reduced diffusing capacity for carbon monoxide is most consistent with which condition when combined with obstruction?
- Asthma
- Emphysema
- Chronic bronchitis without parenchymal destruction
- Vocal cord dysfunction
Correct answer: Emphysema
Emphysema is correct. A reduced diffusing capacity for carbon monoxide reflects loss of alveolar-capillary surface area, which is the hallmark of emphysema and distinguishes it from other obstructive diseases. Asthma and uncomplicated chronic bronchitis typically have a normal or near-normal diffusing capacity, and vocal cord dysfunction is an upper-airway problem that does not impair gas diffusion.
- A 42-year-old man with HIV and a CD4 count of 90 cells per microliter presents with several weeks of progressive dyspnea, dry cough, and a chest radiograph showing diffuse bilateral interstitial infiltrates. His lactate dehydrogenase is elevated. What is the most likely diagnosis and treatment?
- Pneumocystis pneumonia treated with trimethoprim-sulfamethoxazole
- Bacterial lobar pneumonia treated with amoxicillin
- Pulmonary tuberculosis treated with four-drug therapy
- Aspergillosis treated with voriconazole
Correct answer: Pneumocystis pneumonia treated with trimethoprim-sulfamethoxazole
Pneumocystis pneumonia treated with trimethoprim-sulfamethoxazole is correct. In a patient with advanced HIV and a CD4 count below 200, subacute dyspnea, dry cough, diffuse interstitial infiltrates, and elevated lactate dehydrogenase strongly suggest Pneumocystis jirovecii pneumonia, for which trimethoprim-sulfamethoxazole is first-line. The radiographic and clinical pattern and the degree of immunosuppression do not fit lobar bacterial pneumonia, tuberculosis, or aspergillosis as the primary diagnosis.
- A 76-year-old nursing home resident with a recent stroke and impaired swallowing develops fever and a new right lower lobe infiltrate, with the infiltrate located in the area most dependent during recumbency. Which factor most directly predisposed this patient to aspiration pneumonia?
- Impaired swallowing with a depressed cough and gag reflex
- An intact protective airway
- Recent influenza vaccination
- Chronic high-dose inhaled bronchodilators
Correct answer: Impaired swallowing with a depressed cough and gag reflex
Impaired swallowing with depressed protective reflexes is correct. Dysphagia after a stroke, combined with a diminished cough and gag reflex, allows oropharyngeal contents to enter the lower airways, predisposing to aspiration pneumonia in dependent lung segments. An intact airway would protect against aspiration, influenza vaccination reduces viral illness rather than aspiration, and inhaled bronchodilators are not a cause of aspiration.
- A 34-year-old man develops influenza, improves briefly, then several days later worsens with high fever, productive cough, and a new lobar infiltrate. Sputum culture grows gram-positive cocci in clusters. Which organism is the most likely cause of this secondary bacterial pneumonia after influenza?
- Staphylococcus aureus
- Mycoplasma pneumoniae
- Legionella pneumophila
- Pneumocystis jirovecii
Correct answer: Staphylococcus aureus
Staphylococcus aureus is correct. A biphasic illness in which a patient improves after influenza and then deteriorates with a new bacterial pneumonia, with gram-positive cocci in clusters, is characteristic of post-influenza Staphylococcus aureus pneumonia, which can be severe and necrotizing. Mycoplasma and Legionella are not gram-positive cocci in clusters, and Pneumocystis occurs in advanced immunosuppression, not as a typical post-influenza bacterial superinfection.
- A clinician is evaluating a patient with chronic obstructive pulmonary disease using the GOLD spirometric grading. A post-bronchodilator FEV1 that is 45 percent of predicted, with a confirmed FEV1/FVC ratio below 0.70, corresponds to which severity grade?
- GOLD grade 2 (moderate)
- GOLD grade 1 (mild)
- GOLD grade 3 (severe)
- GOLD grade 4 (very severe)
Correct answer: GOLD grade 3 (severe)
GOLD grade 3 (severe) is correct. After confirming obstruction with a ratio below 0.70, the GOLD spirometric grade is based on the percent-predicted FEV1: grade 1 is 80 percent or higher, grade 2 is 50 to 79 percent, grade 3 is 30 to 49 percent, and grade 4 is below 30 percent. An FEV1 of 45 percent of predicted falls into the severe grade 3 category.
- A 48-year-old woman with no smoking history is found to have a peripheral lung mass, and biopsy shows malignant cells forming glandular structures and producing mucin. Which is the most common type of lung cancer overall and the type most often seen in nonsmokers?
- Large cell carcinoma
- Small cell carcinoma
- Squamous cell carcinoma
- Adenocarcinoma
Correct answer: Adenocarcinoma
Adenocarcinoma is correct. It is the most common type of lung cancer overall, is typically located peripherally, forms glandular structures with mucin production, and is the subtype most frequently seen in nonsmokers. Small cell and squamous cell carcinomas are strongly tied to smoking and are usually central, and large cell carcinoma is less common and undifferentiated.
- A 38-year-old woman with asthma is taught to monitor her control at home using a handheld device that measures the maximum speed of forced exhalation. A reading in the patient's red zone, well below her personal best, should prompt which response?
- Double her inhaled corticosteroid dose only and wait a week
- Stop all medications and rest
- Use her rescue inhaler and seek medical care according to her action plan
- Discontinue peak flow monitoring as it is unreliable
Correct answer: Use her rescue inhaler and seek medical care according to her action plan
Use the rescue inhaler and seek care per the action plan is correct. A peak expiratory flow in the red zone indicates a serious exacerbation, and the patient should use her short-acting bronchodilator and follow her written asthma action plan, which directs urgent medical evaluation. Stopping medications is dangerous, simply adjusting the controller without rescue therapy is inadequate for a red-zone reading, and peak flow monitoring is a valid self-management tool.
- A 55-year-old man presents with cough and fever, and his chest radiograph shows a cavitary lesion with an air-fluid level in a dependent lung segment. He has poor dentition and a history of alcohol use with episodes of loss of consciousness. Which diagnosis best fits these findings?
- A simple pleural effusion
- A lung abscess
- Acute bronchitis
- Pulmonary edema
Correct answer: A lung abscess
A lung abscess is correct. A cavitary lesion with an air-fluid level in a dependent segment, in a patient with poor dentition and risk of aspiration from alcohol-related loss of consciousness, is characteristic of a lung abscess from aspiration of oral anaerobes. A pleural effusion appears as layering fluid without a cavity, acute bronchitis lacks cavitation, and pulmonary edema produces diffuse interstitial findings rather than a focal cavity.
- A 50-year-old man with HIV has a positive tuberculin skin test with no symptoms and a normal chest radiograph. Which term and management best describe his status?
- Latent tuberculosis infection requiring treatment to prevent reactivation
- Active pulmonary tuberculosis requiring four-drug therapy
- A false-positive result requiring no action
- Disseminated tuberculosis requiring isolation
Correct answer: Latent tuberculosis infection requiring treatment to prevent reactivation
Latent tuberculosis infection requiring treatment is correct. A positive tuberculin skin test with no symptoms and a normal radiograph indicates latent infection, and treatment is recommended, especially in an immunocompromised host such as a patient with HIV, to prevent progression to active disease. Without symptoms or radiographic findings, he does not have active or disseminated disease, and a positive test in a high-risk patient should not be dismissed as false.
- A 40-year-old immunocompromised man presents with fever, cough, hemoptysis, and pleuritic chest pain. CT shows a pulmonary nodule surrounded by ground-glass opacity, the so-called halo sign, and cultures grow a branching septate mold. Which infection is most likely?
- Bacterial lobar pneumonia
- Pneumocystis pneumonia
- Invasive pulmonary aspergillosis
- Pulmonary tuberculosis
Correct answer: Invasive pulmonary aspergillosis
Invasive pulmonary aspergillosis is correct. In a severely immunocompromised patient, a nodule with a surrounding halo of ground-glass opacity and a branching septate mold on culture is characteristic of invasive Aspergillus infection. Pneumocystis produces diffuse interstitial infiltrates, bacterial pneumonia produces consolidation, and tuberculosis typically causes cavitary or upper-lobe disease without the angioinvasive halo sign.
- A previously healthy young adult living in the Ohio and Mississippi River valleys develops a self-limited flu-like illness with cough after exploring a cave with bat droppings. A chest radiograph later shows hilar lymphadenopathy and small calcified granulomas. Which fungal infection is most likely?
- Blastomycosis
- Coccidioidomycosis
- Cryptococcosis
- Histoplasmosis
Correct answer: Histoplasmosis
Histoplasmosis is correct. Histoplasma capsulatum is endemic to the Ohio and Mississippi River valleys and is associated with exposure to bird or bat droppings, as in caves, classically causing a self-limited respiratory illness with hilar adenopathy and calcified granulomas in immunocompetent hosts. Coccidioidomycosis is endemic to the southwestern United States, while cryptococcosis and blastomycosis have different exposures and clinical patterns.
- A 45-year-old man with a forced vital capacity that is preserved but a chronically elevated carbon dioxide level is suspected of having a neuromuscular cause of respiratory compromise. Which measurement best assesses the strength of the respiratory muscles?
- Maximal inspiratory and expiratory pressures
- Diffusing capacity for carbon monoxide
- The FEV1/FVC ratio
- Peak expiratory flow rate alone
Correct answer: Maximal inspiratory and expiratory pressures
Maximal inspiratory and expiratory pressures are correct. These measurements directly assess respiratory muscle strength and are reduced in neuromuscular disease causing ventilatory failure. The diffusing capacity assesses gas transfer across the alveolar membrane, the FEV1/FVC ratio assesses airflow obstruction, and peak expiratory flow primarily reflects large-airway obstruction rather than overall muscle strength.
- A 33-year-old woman has recurrent pneumonias all localized to the same lung segment, and bronchoscopy reveals an endobronchial lesion partially obstructing the airway. Which mechanism best explains why obstruction predisposes to recurrent pneumonia in the same location?
- Impaired clearance of secretions distal to the obstruction promoting infection
- Increased mucociliary clearance from the irritation
- Enhanced immune surveillance at the obstruction
- Excessive surfactant production distal to the lesion
Correct answer: Impaired clearance of secretions distal to the obstruction promoting infection
Impaired clearance of secretions distal to the obstruction is correct. A fixed endobronchial obstruction prevents normal drainage and clearance of secretions in the segment beyond it, allowing organisms to accumulate and produce recurrent infections in the same location, which should prompt evaluation for an obstructing lesion such as a tumor. Obstruction reduces rather than enhances clearance and immune defense, and surfactant overproduction is not the mechanism.
- A 29-year-old woman presents with hemoptysis, and after evaluation a small amount of blood is determined to originate from the lower respiratory tract rather than the gastrointestinal tract. Which feature most supports a pulmonary (hemoptysis) source rather than hematemesis?
- Blood accompanied by melena
- Dark, coffee-ground material that is acidic
- Bright red, frothy blood that is alkaline and may be mixed with sputum
- Blood preceded by nausea and vomiting of food
Correct answer: Bright red, frothy blood that is alkaline and may be mixed with sputum
Bright red, frothy, alkaline blood mixed with sputum is correct. Hemoptysis from the lower respiratory tract is typically bright red and frothy, has an alkaline pH, and may be mixed with sputum or accompanied by cough. Coffee-ground acidic material, associated melena, and preceding nausea and vomiting of food all point to a gastrointestinal (hematemesis) source rather than a pulmonary one.
- A 6-year-old with poorly controlled asthma is being stepped up in therapy because of frequent symptoms despite a low-dose inhaled corticosteroid. Which adjustment aligns with stepwise asthma management before adding systemic corticosteroids?
- Switch entirely to as-needed short-acting beta-agonist
- Increase to a medium-dose inhaled corticosteroid or add a long-acting beta-agonist
- Begin chronic daily oral corticosteroids immediately
- Stop the inhaled corticosteroid and start an antibiotic
Correct answer: Increase to a medium-dose inhaled corticosteroid or add a long-acting beta-agonist
Increasing the inhaled corticosteroid dose or adding a long-acting beta-agonist is correct. When low-dose inhaled corticosteroid therapy fails to control asthma, the next step is to escalate the controller, either by increasing the inhaled corticosteroid dose or adding a long-acting beta-agonist, before resorting to chronic systemic steroids. Reverting to rescue therapy alone abandons controller treatment, chronic oral steroids are a last resort, and antibiotics do not treat poorly controlled asthma.
- A 25-year-old man has a recurrent primary spontaneous pneumothorax on the same side for the third time. Beyond simple drainage, which intervention is most appropriate to prevent future recurrences?
- Pleurodesis or surgical bullectomy with pleurectomy
- Indefinite supplemental oxygen
- Lifelong prophylactic antibiotics
- Daily inhaled corticosteroids
Correct answer: Pleurodesis or surgical bullectomy with pleurectomy
Pleurodesis or surgical bullectomy with pleurectomy is correct. Recurrent spontaneous pneumothorax is an indication for a definitive procedure such as pleurodesis or surgical resection of blebs with pleurectomy to obliterate the pleural space and prevent recurrence. Supplemental oxygen, antibiotics, and inhaled corticosteroids do not address the underlying mechanical predisposition to recurrent air leaks.
- A 70-year-old man with chronic obstructive pulmonary disease asks how to reduce his risk of exacerbations and death. Besides inhaler therapy, which intervention provides the greatest benefit in slowing disease progression and improving survival?
- Chronic oral corticosteroids
- A daily multivitamin
- Routine annual chest computed tomography
- Smoking cessation
Correct answer: Smoking cessation
Smoking cessation is correct. It is the single most effective intervention to slow the decline in lung function and improve survival in chronic obstructive pulmonary disease, in addition to long-term oxygen when indicated. A multivitamin does not alter disease progression, routine CT is not a treatment, and chronic oral corticosteroids cause significant harm without survival benefit in stable disease.
- A 55-year-old man with a malignant pleural effusion has recurrent symptomatic fluid reaccumulation after repeated thoracentesis. Which procedure is most appropriate to provide durable palliation of the recurrent effusion?
- A single additional thoracentesis with observation
- Pleurodesis or placement of an indwelling pleural catheter
- Diuretic therapy alone
- Systemic anticoagulation
Correct answer: Pleurodesis or placement of an indwelling pleural catheter
Pleurodesis or an indwelling pleural catheter is correct. Recurrent symptomatic malignant pleural effusions are best palliated by a definitive procedure such as chemical pleurodesis or an indwelling tunneled pleural catheter for ongoing drainage. Repeated thoracentesis alone is temporary, diuretics treat transudative effusions of heart failure, and anticoagulation has no role in managing a malignant effusion.
- A 62-year-old man hospitalized for pneumonia is found on day three to have a serum creatinine that has risen from 0.9 to 2.7 mg/dL, but his urine output remains greater than 1,500 mL per day. How should this pattern of acute kidney injury be classified with respect to urine volume?
- Anuric acute kidney injury
- Nonoliguric acute kidney injury
- Oliguric acute kidney injury
- Postobstructive anuria
Correct answer: Nonoliguric acute kidney injury
This is nonoliguric acute kidney injury, in which the creatinine rises despite preserved or even high urine output, a presentation that often carries a more favorable prognosis than oliguric injury. Anuria denotes essentially no urine, oliguria denotes a markedly reduced volume, and postobstructive anuria refers to blockage, none of which fit a patient still making over 1,500 mL daily.
- A clinician reviewing a patient with acute kidney injury notes that aminoglycoside antibiotics are a classic nephrotoxin. At which part of the nephron do aminoglycosides primarily exert their direct toxic effect?
- The glomerular capillary endothelium
- The collecting duct principal cells
- The proximal tubular epithelial cells
- The afferent arteriole smooth muscle
Correct answer: The proximal tubular epithelial cells
Aminoglycosides are taken up by and accumulate within proximal tubular epithelial cells, where they cause direct toxic injury and a form of acute tubular necrosis. They do not primarily damage the glomerular endothelium, the collecting duct principal cells, or the afferent arteriolar smooth muscle, which is why monitoring centers on tubular function during therapy.
- A 70-year-old woman started on a nonsteroidal anti-inflammatory drug for arthritis develops a reversible rise in creatinine. Which hemodynamic mechanism best explains how this drug class precipitates acute kidney injury in a susceptible patient?
- Dilation of the efferent arteriole raising filtration pressure
- Direct immune-complex deposition in the glomerulus
- Crystallization of the drug within the tubular lumen
- Constriction of the afferent arteriole from reduced prostaglandin-mediated vasodilation
Correct answer: Constriction of the afferent arteriole from reduced prostaglandin-mediated vasodilation
Nonsteroidal anti-inflammatory drugs inhibit prostaglandins that normally dilate the afferent arteriole, so in a patient dependent on that vasodilation the afferent arteriole constricts and glomerular perfusion falls. They do not act by dilating the efferent arteriole, depositing immune complexes, or forming intratubular crystals in this hemodynamic form of injury.
- A patient with chronic kidney disease and an estimated glomerular filtration rate of 22 mL/min/1.73 m2 is being evaluated for whether to begin planning vascular access. At which estimated glomerular filtration rate threshold is timely referral for surgical creation of a permanent dialysis access generally recommended so the access can mature before it is needed?
- Around 60 mL/min/1.73 m2
- When approaching 15 to 20 mL/min/1.73 m2
- Around 75 mL/min/1.73 m2
- Around 90 mL/min/1.73 m2
Correct answer: When approaching 15 to 20 mL/min/1.73 m2
Referral for creation of a permanent dialysis access such as an arteriovenous fistula is generally recommended as the filtration rate approaches roughly 15 to 20 mL/min/1.73 m2, because a fistula needs months to mature before it can be used. Filtration rates of 60, 75, or 90 reflect much earlier, milder disease where access creation would be premature.
- A 66-year-old man with chronic kidney disease has a sustained blood pressure of 150/92 mmHg and a urine albumin-to-creatinine ratio of 600 mg/g. According to current guidance, which medication class should anchor his antihypertensive regimen given the significant albuminuria?
- A peripheral alpha-1 blocker
- A direct arterial vasodilator
- A renin-angiotensin system blocker
- A loop diuretic used as monotherapy
Correct answer: A renin-angiotensin system blocker
A renin-angiotensin system blocker should anchor the regimen in chronic kidney disease with significant albuminuria, because reducing intraglomerular pressure lowers proteinuria and slows progression in addition to controlling blood pressure. An alpha-1 blocker, a direct vasodilator, or a loop diuretic alone lower pressure but lack the specific albuminuria-reducing, kidney-protective benefit.
- A patient with advanced chronic kidney disease and persistent metabolic acidosis is found to have a serum bicarbonate of 16 mmol/L. Beyond its effect on acid-base status, why is correcting this chronic acidosis with oral alkali therapy recommended?
- It slows muscle protein catabolism and may slow progression of kidney disease
- It reverses the underlying glomerular scarring
- It eliminates the need for blood pressure control
- It cures the anemia of chronic kidney disease
Correct answer: It slows muscle protein catabolism and may slow progression of kidney disease
Treating the chronic metabolic acidosis of kidney disease with oral alkali is recommended because correcting the low bicarbonate reduces muscle protein breakdown and bone buffering and may slow the decline in kidney function. It does not reverse established glomerular scarring, cure the anemia, or remove the need for blood pressure management.
- A 54-year-old woman on chronic hemodialysis is noted to have a rising parathyroid hormone level despite phosphate binders, and a vitamin D-related agent is considered. Which active form of vitamin D requires the kidney for its final activating hydroxylation step, a step lost in advanced kidney disease?
- Cholecalciferol (vitamin D3)
- 1,25-dihydroxyvitamin D (calcitriol)
- 25-hydroxyvitamin D (calcidiol)
- Ergocalciferol (vitamin D2)
Correct answer: 1,25-dihydroxyvitamin D (calcitriol)
The kidney performs the final 1-alpha-hydroxylation that converts 25-hydroxyvitamin D into 1,25-dihydroxyvitamin D, the active form calcitriol, so advanced kidney disease impairs this activation and contributes to secondary hyperparathyroidism. Cholecalciferol and ergocalciferol are precursors, and 25-hydroxyvitamin D is the storage form awaiting that renal step.
- A medical assistant is taught how to properly collect a specimen used to quantify albuminuria in patients with chronic kidney disease. Which specimen is preferred for screening because it conveniently accounts for variations in urine concentration?
- A single random urine dipstick read by color only
- A 6-hour overnight urine volume
- A serum creatinine drawn while fasting
- A spot urine albumin-to-creatinine ratio
Correct answer: A spot urine albumin-to-creatinine ratio
A spot urine albumin-to-creatinine ratio is preferred for screening because dividing albumin by creatinine corrects for how dilute or concentrated the sample is, giving a reliable estimate without a timed collection. A dipstick read by color alone is semi-quantitative, a serum creatinine does not measure albuminuria, and a 6-hour overnight volume is not the standard albuminuria screen.
- A 48-year-old man with a potassium of 6.6 mmol/L receives intravenous calcium gluconate, then insulin with dextrose, and a loop diuretic. About how soon after administration does intravenous calcium begin to exert its protective cardiac effect?
- After about 6 hours
- Within minutes
- After about 12 hours
- Not until the next dialysis session
Correct answer: Within minutes
Intravenous calcium begins protecting the heart within minutes by raising the threshold for myocardial depolarization, which is why it is given first when electrocardiographic changes accompany severe hyperkalemia. Its onset is far faster than 6 or 12 hours, and it does not depend on a dialysis session, although its membrane-stabilizing effect is also short-lived.
- A clinician explains why a single dose of intravenous calcium does not solve hyperkalemia. Which statement best describes the duration of the cardioprotective effect of calcium in this setting?
- It permanently corrects the membrane abnormality
- It lasts approximately 24 hours from one dose
- It is transient, lasting roughly 30 to 60 minutes, so it may need repeating
- It only takes effect after several hours
Correct answer: It is transient, lasting roughly 30 to 60 minutes, so it may need repeating
The cardioprotective effect of intravenous calcium is transient, generally lasting only about 30 to 60 minutes, so the dose may need to be repeated while definitive potassium-lowering measures take hold. It does not provide a permanent correction or a full day of protection, and its onset is rapid rather than delayed.
- A patient with end-stage kidney disease repeatedly presents with hyperkalemia. Beyond medications, which dietary source is most important to counsel the patient to limit to help prevent recurrent hyperkalemia?
- Potassium-rich foods such as bananas, oranges, potatoes, and salt substitutes
- Refined white bread and pasta
- Foods high in simple sugars
- Foods high in saturated fat
Correct answer: Potassium-rich foods such as bananas, oranges, potatoes, and salt substitutes
Counseling should focus on limiting potassium-rich foods such as bananas, oranges, potatoes, tomatoes, and especially salt substitutes that contain potassium chloride, because dietary potassium is a major contributor when the failing kidney cannot excrete it. Refined starches, simple sugars, and saturated fats are not the relevant source of the potassium load.
- A laboratory reports a serum potassium of 6.4 mmol/L from a sample drawn from a patient with a platelet count of 900,000 per microliter and a white cell count of 70,000 per microliter, yet the patient is asymptomatic with a normal electrocardiogram. Which explanation best accounts for this result?
- Genuine life-threatening hyperkalemia requiring immediate dialysis
- Pseudohyperkalemia from potassium release by cells during clotting
- Hyperkalemia from a renin-secreting tumor
- True hyperkalemia from tumor lysis already in progress
Correct answer: Pseudohyperkalemia from potassium release by cells during clotting
Marked thrombocytosis or leukocytosis can cause pseudohyperkalemia, because the abundant cells release potassium as the specimen clots, falsely elevating the serum value while a plasma sample or the normal electrocardiogram reflects the true level. This makes immediate dialysis, a renin-secreting tumor, or active tumor lysis unlikely explanations for an asymptomatic patient.
- A 39-year-old woman with the syndrome of inappropriate antidiuretic hormone secretion has persistent hyponatremia at 126 mmol/L despite fluid restriction, and the team adds an oral agent that promotes free water excretion by blocking the vasopressin receptor. Which medication class accomplishes this?
- A thiazide diuretic
- A nonsteroidal anti-inflammatory drug
- A vasopressin receptor antagonist (vaptan)
- A mineralocorticoid receptor antagonist
Correct answer: A vasopressin receptor antagonist (vaptan)
A vasopressin receptor antagonist, or vaptan, promotes excretion of solute-free water by blocking the action of antidiuretic hormone in the collecting duct, raising the serum sodium in resistant syndrome of inappropriate antidiuretic hormone secretion. A thiazide can worsen hyponatremia, while a nonsteroidal agent and a mineralocorticoid antagonist do not target the vasopressin receptor to drive water excretion.
- A patient with chronic hyponatremia at 118 mmol/L is corrected too rapidly, and several days later develops dysarthria, dysphagia, and a spastic quadriparesis. Which complication has most likely occurred?
- Wernicke encephalopathy
- Cerebral edema
- Subdural hematoma
- Osmotic demyelination syndrome
Correct answer: Osmotic demyelination syndrome
Osmotic demyelination syndrome most likely occurred, as overly rapid correction of chronic hyponatremia injures myelin in the pons and produces delayed dysarthria, dysphagia, and spastic quadriparesis. Cerebral edema follows rapid correction of hypernatremia rather than hyponatremia, Wernicke encephalopathy is a thiamine deficiency syndrome, and a subdural hematoma would not arise simply from the correction rate.
- A clinician evaluating a euvolemic hyponatremic patient wants to exclude two hormonal disorders that mimic the syndrome of inappropriate antidiuretic hormone secretion before assigning that diagnosis. Which pair of conditions should be excluded first?
- Diabetes mellitus and acromegaly
- Hypothyroidism and adrenal insufficiency
- Hyperparathyroidism and pheochromocytoma
- Cushing syndrome and hyperaldosteronism
Correct answer: Hypothyroidism and adrenal insufficiency
Hypothyroidism and adrenal insufficiency must be excluded before diagnosing the syndrome of inappropriate antidiuretic hormone secretion, because both can produce a euvolemic hyponatremia that closely mimics it and both are correctable. The other listed endocrine disorders are not the classic mimics that the diagnostic criteria specifically require ruling out.
- A 71-year-old man started on a thiazide diuretic two weeks ago presents with a serum sodium of 125 mmol/L. Which mechanism best explains thiazide-induced hyponatremia?
- Increased free water clearance
- Stimulation of aldosterone causing sodium loss only
- Direct destruction of the collecting duct
- Impaired urinary dilution with continued water retention while sodium is lost
Correct answer: Impaired urinary dilution with continued water retention while sodium is lost
Thiazides act in the distal tubule and impair the kidney's ability to generate dilute urine, so free water is retained while sodium and potassium are lost, lowering the serum sodium. They do not increase free water clearance, work primarily by stimulating aldosterone, or destroy the collecting duct, which is why elderly patients are especially susceptible.
- A clinician is interpreting an arterial blood gas with a metabolic acidosis and applies Winter's formula to judge respiratory compensation. What does Winter's formula predict in a patient with a primary metabolic acidosis?
- The expected serum bicarbonate for the measured carbon dioxide
- The expected partial pressure of carbon dioxide for the measured bicarbonate
- The anion gap from the electrolytes
- The free water deficit
Correct answer: The expected partial pressure of carbon dioxide for the measured bicarbonate
Winter's formula predicts the expected partial pressure of carbon dioxide for a given bicarbonate in a primary metabolic acidosis, letting the clinician judge whether respiratory compensation is adequate or whether a separate respiratory disorder coexists. It does not calculate the anion gap, the free water deficit, or the expected bicarbonate from carbon dioxide.
- A patient with a high anion gap metabolic acidosis is found to have a large osmolal gap as well. Which broad category of cause does the combination of a high anion gap acidosis and an elevated osmolal gap most strongly suggest?
- Simple diarrheal bicarbonate loss
- Chronic respiratory acidosis
- Toxic alcohol ingestion such as methanol or ethylene glycol
- Uncomplicated dehydration
Correct answer: Toxic alcohol ingestion such as methanol or ethylene glycol
A high anion gap metabolic acidosis paired with an elevated osmolal gap most strongly suggests a toxic alcohol ingestion such as methanol or ethylene glycol, whose parent alcohols raise the osmolal gap while their acid metabolites widen the anion gap. Diarrheal bicarbonate loss causes a normal-gap acidosis, and respiratory acidosis and simple dehydration do not produce this dual-gap pattern.
- A patient who ingested ethylene glycol develops a high anion gap metabolic acidosis, acute kidney injury, and calcium oxalate crystals in the urine. Which antidote works by blocking the enzyme that converts ethylene glycol into its toxic acid metabolites?
- Naloxone
- N-acetylcysteine
- Flumazenil
- Fomepizole, an alcohol dehydrogenase inhibitor
Correct answer: Fomepizole, an alcohol dehydrogenase inhibitor
Fomepizole works by inhibiting alcohol dehydrogenase, the enzyme that converts ethylene glycol into the toxic acids responsible for the metabolic acidosis and oxalate-mediated kidney injury. Naloxone reverses opioids, flumazenil reverses benzodiazepines, and N-acetylcysteine treats acetaminophen toxicity, none of which address this ingestion.
- A 23-year-old man is admitted after lying unconscious on a hard floor for many hours following alcohol intoxication. He has swollen, tender thighs and dark urine, and rhabdomyolysis is suspected. Beyond aggressive intravenous fluids, which laboratory value most urgently guides immediate cardiac risk because of its release from damaged muscle?
- Serum sodium
- Serum potassium
- Serum chloride
- Serum bicarbonate
Correct answer: Serum potassium
Serum potassium most urgently guides immediate cardiac risk in rhabdomyolysis, because necrotic muscle releases large amounts of intracellular potassium that can provoke fatal arrhythmias. Sodium, chloride, and bicarbonate are monitored as well, but potassium is the electrolyte whose acute elevation poses the most immediate threat to the heart.
- A patient with rhabdomyolysis and a creatine kinase of 40,000 U/L is started on intravenous fluids. Which urine output goal is generally targeted to help flush myoglobin and protect the kidneys during treatment?
- A urine output deliberately kept below 20 mL per hour
- No urine output until creatinine normalizes
- A brisk urine output of roughly 200 to 300 mL per hour
- A urine output of exactly 10 mL per hour
Correct answer: A brisk urine output of roughly 200 to 300 mL per hour
Aggressive fluids are titrated to achieve a brisk urine output, often in the range of about 200 to 300 mL per hour, to flush myoglobin through the tubules and reduce pigment-induced injury. Deliberately restricting urine output or aiming for very low volumes would allow myoglobin to obstruct and damage the tubules.
- A patient recovering from a crush injury complicated by rhabdomyolysis is found to have a serum phosphate of 6.8 mg/dL during the acute phase. Which mechanism explains the hyperphosphatemia seen in acute rhabdomyolysis?
- Release of intracellular phosphate from damaged muscle cells
- Excessive renal phosphate excretion
- Increased gastrointestinal phosphate binding
- Overproduction of parathyroid hormone
Correct answer: Release of intracellular phosphate from damaged muscle cells
Hyperphosphatemia in acute rhabdomyolysis results from the release of large stores of intracellular phosphate when muscle cells are destroyed, compounded by impaired renal excretion if acute kidney injury develops. It is not caused by enhanced phosphate excretion, increased gut binding, or parathyroid hormone excess.
- A 45-year-old man with nephrotic syndrome is being counseled about a serious thrombotic risk unique to the heavy protein losses of his condition. Which intervention is sometimes considered to reduce thromboembolic complications in patients with severe nephrotic syndrome and very low albumin?
- Routine antiplatelet therapy with no anticoagulant ever
- Prophylactic anticoagulation
- Daily potassium supplementation
- Chronic loop diuretic monotherapy
Correct answer: Prophylactic anticoagulation
Prophylactic anticoagulation is sometimes considered in severe nephrotic syndrome with very low albumin, because urinary loss of antithrombin and other anticoagulant proteins creates a hypercoagulable state that predisposes to venous thrombosis. Potassium supplementation and loop diuretic monotherapy do not address thrombotic risk, and the issue here is anticoagulation rather than antiplatelet therapy alone.
- A child with nephrotic syndrome from minimal change disease is started on the standard first-line therapy that typically induces remission of the proteinuria. Which medication class is used as initial treatment for steroid-sensitive minimal change disease?
- Loop diuretics
- Beta-blockers
- Corticosteroids
- Aminoglycoside antibiotics
Correct answer: Corticosteroids
Corticosteroids are the first-line therapy for minimal change disease, which is characteristically steroid-sensitive and usually responds with remission of proteinuria. Loop diuretics may help control edema symptomatically, but beta-blockers and aminoglycosides have no role in inducing remission of this glomerular disease.
- A clinician distinguishes nephritic from nephrotic glomerular disease at the bedside. Which set of findings is most characteristic of a nephritic syndrome rather than a nephrotic syndrome?
- Proteinuria over 3.5 grams per day with hypoalbuminemia and hyperlipidemia
- Heavy edema with frothy urine and a bland sediment
- Hematuria with red blood cell casts, hypertension, and mild proteinuria
- Lipiduria with oval fat bodies and minimal hematuria
Correct answer: Hematuria with red blood cell casts, hypertension, and mild proteinuria
Hematuria with red blood cell casts, hypertension, and lesser degrees of proteinuria are most characteristic of a nephritic syndrome, reflecting inflammatory glomerular injury. Heavy proteinuria over 3.5 grams with hypoalbuminemia, hyperlipidemia, frothy urine, a bland sediment, and oval fat bodies all describe the nephrotic syndrome instead.
- A 35-year-old man with longstanding hepatitis C is found to have hematuria, proteinuria, a low complement level, palpable purpura, and circulating cryoglobulins. Which glomerular pattern is most classically associated with this presentation?
- Minimal change disease
- Thin basement membrane disease
- Membranoproliferative glomerulonephritis
- Diabetic nodular glomerulosclerosis
Correct answer: Membranoproliferative glomerulonephritis
Membranoproliferative glomerulonephritis is most classically associated with hepatitis C and cryoglobulinemia, presenting with a mixed nephritic-nephrotic picture, low complement, and palpable purpura. Minimal change disease and thin basement membrane disease lack the hypocomplementemia and cryoglobulins, and diabetic glomerulosclerosis requires longstanding diabetes rather than this viral, cryoglobulin-driven process.
- A 26-year-old woman presents with persistent microscopic hematuria, a strong family history of similar benign hematuria, normal kidney function, and no proteinuria or hearing loss. Biopsy would show uniformly thinned glomerular basement membranes. Which diagnosis best fits?
- Rapidly progressive glomerulonephritis
- Goodpasture disease
- Acute tubular necrosis
- Thin basement membrane disease (benign familial hematuria)
Correct answer: Thin basement membrane disease (benign familial hematuria)
Thin basement membrane disease, also called benign familial hematuria, best fits isolated persistent microscopic hematuria with a family history, preserved function, no proteinuria, and uniformly thin basement membranes, and it carries an excellent prognosis. Rapidly progressive glomerulonephritis and Goodpasture disease cause declining function, and acute tubular necrosis is a tubular rather than familial glomerular process.
- A 48-year-old woman undergoing imaging for back pain is incidentally found to have several small medullary cysts with tiny calcifications in a striated brush pattern, and she has a history of recurrent calcium stones. Which condition best explains these findings?
- Autosomal dominant polycystic kidney disease
- Acquired cystic kidney disease of dialysis
- Medullary sponge kidney
- A simple solitary cortical cyst
Correct answer: Medullary sponge kidney
Medullary sponge kidney best explains incidental dilated medullary collecting ducts with small calcifications producing a striated, paintbrush appearance and a tendency to recurrent calcium stones, and it is usually benign. Autosomal dominant polycystic kidney disease produces large cortical and medullary cysts, acquired cystic disease relates to long-term dialysis, and a solitary cortical cyst does not produce this medullary pattern.
- A patient with autosomal dominant polycystic kidney disease and rapidly enlarging kidneys is started on a medication shown to slow cyst growth and the decline in kidney function. Which agent, a vasopressin V2 receptor antagonist, is used for this purpose?
- Furosemide
- Lisinopril
- Allopurinol
- Tolvaptan
Correct answer: Tolvaptan
Tolvaptan, a vasopressin V2 receptor antagonist, is used in selected patients with rapidly progressing autosomal dominant polycystic kidney disease because it slows cyst growth and the decline in kidney function. Furosemide manages volume, lisinopril controls blood pressure, and allopurinol lowers uric acid, but none of these specifically slow cyst progression.
- A 32-year-old man with a family history of early kidney failure is found to have an estimated glomerular filtration rate of 88 mL/min/1.73 m2, hypertension, and bilateral flank fullness, prompting renal ultrasound. Which finding would confirm autosomal dominant polycystic kidney disease in this at-risk adult?
- A single small cortical cyst
- Bilateral hydronephrosis without cysts
- Multiple bilateral renal cysts meeting age-based diagnostic criteria
- Diffusely echogenic kidneys without cysts
Correct answer: Multiple bilateral renal cysts meeting age-based diagnostic criteria
Multiple bilateral renal cysts meeting age-specific count criteria confirm autosomal dominant polycystic kidney disease in an at-risk adult, since the diagnosis on ultrasound depends on the number of cysts relative to the patient's age. A single cortical cyst is a common benign finding, while bilateral hydronephrosis or echogenic kidneys without cysts indicate other processes.
- A 38-year-old woman with recurrent infection-related kidney stones is found to have stones composed of magnesium ammonium phosphate that form a large branching cast of the renal pelvis. Which type of stone and associated organism best explain this finding?
- Uric acid stones from persistently acidic urine
- Cystine stones from an inherited transport defect
- Calcium oxalate stones from hyperoxaluria
- Struvite stones from urease-producing bacteria
Correct answer: Struvite stones from urease-producing bacteria
Struvite stones, made of magnesium ammonium phosphate, form in alkaline urine produced by urease-producing bacteria such as Proteus and can grow into large branching staghorn calculi filling the collecting system. Uric acid stones form in acidic urine, cystine stones arise from cystinuria, and calcium oxalate stones are not associated with urease-producing infection.
- A 44-year-old man presents with acute, severe, colicky left flank pain radiating to the groin with gross hematuria, and obstructive urolithiasis is suspected. Which imaging study is the preferred initial test to confirm a stone and assess its size and location?
- Plain abdominal radiograph alone
- Noncontrast helical computed tomography of the abdomen and pelvis
- Voiding cystourethrogram
- Nuclear renal scan
Correct answer: Noncontrast helical computed tomography of the abdomen and pelvis
Noncontrast helical computed tomography of the abdomen and pelvis is the preferred initial test for suspected nephrolithiasis because it detects nearly all stones regardless of composition and shows their size and location. A plain radiograph misses radiolucent stones, a voiding cystourethrogram evaluates reflux, and a nuclear renal scan assesses function rather than acute stones.
- A patient passes a small ureteral stone after several days, and the team had used medical expulsive therapy to facilitate passage. Which medication class is most commonly used to relax ureteral smooth muscle and promote spontaneous passage of a distal ureteral stone?
- Beta-blockers
- Loop diuretics
- Calcium channel blockers used as first line over alpha-blockers
- Alpha-blockers
Correct answer: Alpha-blockers
Alpha-blockers are the most commonly used agents for medical expulsive therapy, relaxing smooth muscle in the distal ureter to facilitate passage of a small stone. Beta-blockers and loop diuretics do not aid stone passage, and while calcium channel blockers were studied, alpha-blockers are the preferred class for this purpose.
- A 28-year-old woman is counseled before starting single-dose methotrexate for an unruptured tubal ectopic pregnancy. Which dietary instruction should she be given to avoid reducing the drug's effectiveness?
- Avoid foods and supplements containing folic acid during treatment
- Increase intake of vitamin C-rich foods
- Take iron supplements with each meal
- Eat a high-protein diet to boost the response
Correct answer: Avoid foods and supplements containing folic acid during treatment
Avoiding folic acid-containing foods and supplements during methotrexate treatment is the correct instruction. Methotrexate works by antagonizing folate metabolism in the rapidly dividing trophoblast, so supplemental folate can counteract its action and reduce treatment success. Patients are also advised to avoid nonsteroidal anti-inflammatory drugs and alcohol during therapy.
- A 30-year-old woman with a positive pregnancy test and abdominal pain has a transvaginal ultrasound showing a gestational sac located outside the uterus near the cervix at the level of a prior cesarean scar. Which feature of this implantation site makes it particularly dangerous?
- It always resolves without any treatment
- It is associated with very low beta-hCG levels
- It carries a high risk of catastrophic hemorrhage and uterine rupture
- It guarantees a normal term delivery
Correct answer: It carries a high risk of catastrophic hemorrhage and uterine rupture
A cesarean scar implantation carries a high risk of catastrophic hemorrhage and uterine rupture, which makes it particularly dangerous. The pregnancy implants in the fibrous, poorly vascularized scar of a prior cesarean, where invasion can erode through the thinned uterine wall. Early recognition allows treatment before life-threatening bleeding occurs.
- A 53-year-old woman in menopause asks why she is being counseled about heart and bone health now that her periods have stopped. Which physiologic change of menopause most directly increases her cardiovascular risk over time?
- A rise in protective estrogen levels
- An increase in circulating progesterone
- A decrease in low-density lipoprotein cholesterol
- Loss of the favorable lipid effects of estrogen
Correct answer: Loss of the favorable lipid effects of estrogen
Loss of the favorable lipid effects of estrogen most directly increases cardiovascular risk after menopause. Estrogen normally helps maintain a healthier lipid profile, and its decline is associated with rising low-density lipoprotein cholesterol and increasing cardiovascular risk, which is why lifestyle and risk-factor management gain importance in postmenopausal women.
- A 49-year-old woman reports irregular menstrual cycles, occasional hot flashes, and cycles that vary in length by more than 7 days, but she has not gone a full year without menses. Which stage of reproductive aging does this best describe?
- Premenarche
- The menopausal transition, or perimenopause
- Established postmenopause
- Primary ovarian insufficiency
Correct answer: The menopausal transition, or perimenopause
This best describes the menopausal transition, or perimenopause. It is marked by increasing menstrual cycle irregularity and the onset of vasomotor symptoms as ovarian function fluctuates, but it precedes the 12 months of amenorrhea that define menopause. Recognizing this stage explains symptoms while ovulation and fertility may still intermittently occur.
- A 23-year-old woman with sudden severe right pelvic pain is taken to surgery for suspected ovarian torsion, but at exploration the ovary and tube appear normal and untwisted. Which finding would lead the surgeon to consider an alternative diagnosis on the right side?
- A normal-appearing fallopian tube
- A small physiologic follicle
- An inflamed appendix
- A normal uterine fundus
Correct answer: An inflamed appendix
An inflamed appendix would lead the surgeon to consider appendicitis as the alternative diagnosis. Because right-sided pelvic pain from torsion can mimic appendicitis and vice versa, finding normal adnexa prompts inspection of the appendix. This overlap is a key reason both conditions are considered in a woman with acute right lower quadrant or pelvic pain.
- A 27-year-old woman with a known 7 cm ovarian cyst develops intermittent severe pelvic pain that comes and goes over several hours. Which characteristic of this pain pattern is most suggestive of intermittent ovarian torsion rather than a ruptured cyst?
- Constant pain that never changes
- Pain that recurs in waves as the ovary twists and untwists
- Pain that only occurs after eating
- Pain that completely resolves with antibiotics
Correct answer: Pain that recurs in waves as the ovary twists and untwists
Pain that recurs in waves as the ovary twists and untwists is most suggestive of intermittent torsion. A heavy cyst can cause the ovary to rotate partially and then spontaneously detorse, producing colicky, recurrent pain rather than the sudden persistent pain of complete torsion or the acute onset of rupture. This pattern warrants prompt imaging and surgical evaluation.
- A 29-year-old woman at 32 weeks gestation with a known placenta previa is admitted after an episode of painless bleeding that has stopped. The fetus is reassuring and she is stable. Which management approach is most appropriate while she remains stable and preterm?
- Immediate cesarean delivery regardless of stability
- Induction of labor with oxytocin
- Therapeutic amniotomy to deliver vaginally
- Expectant inpatient management with monitoring and avoidance of vaginal exams
Correct answer: Expectant inpatient management with monitoring and avoidance of vaginal exams
Expectant inpatient management with monitoring and avoidance of vaginal exams is most appropriate for a stable, preterm patient with placenta previa after bleeding has stopped. This approach prolongs the pregnancy to gain fetal maturity while watching for recurrent hemorrhage, with corticosteroids given for lung maturity. Cesarean delivery is reserved for uncontrolled bleeding or fetal compromise.
- A 31-year-old woman with placenta previa is counseled about an associated condition. Which coexisting abnormality is she at increased risk for, especially with a history of prior cesarean delivery?
- Gestational diabetes
- Placenta accreta spectrum
- Hyperemesis gravidarum
- Cervical insufficiency
Correct answer: Placenta accreta spectrum
She is at increased risk for placenta accreta spectrum, especially with a prior cesarean delivery. A placenta that implants over a previous uterine scar in the lower segment is more likely to invade abnormally into the myometrium, so previa plus prior cesarean prompts careful imaging to evaluate for accreta and planning for possible major hemorrhage at delivery.
- A 24-year-old woman is diagnosed with pelvic inflammatory disease and meets criteria for outpatient treatment. Which clinical situation would instead warrant hospitalization for intravenous therapy?
- A reliable patient with mild symptoms and good follow-up
- Mild cervical motion tenderness alone
- Inability to tolerate oral medications because of nausea and vomiting
- A normal white blood cell count
Correct answer: Inability to tolerate oral medications because of nausea and vomiting
Inability to tolerate oral medications because of nausea and vomiting warrants hospitalization. Other indications include pregnancy, a tubo-ovarian abscess, severe illness with high fever, failure of outpatient therapy, or inability to follow or comply with an outpatient regimen. Mild disease in a reliable patient who can take oral antibiotics is managed as an outpatient.
- A 22-year-old woman is being treated for pelvic inflammatory disease. Which physical examination triad supports the clinical diagnosis?
- Costovertebral angle, suprapubic, and flank tenderness
- Cervical motion, uterine, and adnexal tenderness
- Right upper quadrant, epigastric, and periumbilical tenderness
- Calf, thigh, and groin tenderness
Correct answer: Cervical motion, uterine, and adnexal tenderness
Cervical motion, uterine, and adnexal tenderness form the classic examination triad that supports a clinical diagnosis of pelvic inflammatory disease. The presence of any one of these minimum criteria in a sexually active young woman at risk is enough to begin empiric treatment, because delaying therapy to confirm the diagnosis increases the risk of long-term tubal damage.
- A 30-year-old woman with endometriosis reports that her chief complaints are painful periods, pain with intercourse, and difficulty conceiving. Which classic symptom triad does this represent?
- Fever, chills, and discharge
- Dysmenorrhea, dyspareunia, and infertility
- Polyuria, polydipsia, and weight loss
- Hematuria, dysuria, and frequency
Correct answer: Dysmenorrhea, dyspareunia, and infertility
Dysmenorrhea, dyspareunia, and infertility form the classic symptom triad of endometriosis. Ectopic endometrial implants cause cyclic pain with menses, deep pain during intercourse from involvement of pelvic structures, and impaired fertility from inflammation and adhesions. Recognizing this triad helps raise suspicion for the disease in a woman of reproductive age.
- A 25-year-old woman with polycystic ovary syndrome and obesity asks what single intervention can improve her menstrual regularity, ovulation, and metabolic profile at the same time. Which recommendation is most appropriate as first-line lifestyle therapy?
- Complete fasting on alternate days
- Strict bed rest
- Weight loss through diet and exercise
- High-dose vitamin E supplementation
Correct answer: Weight loss through diet and exercise
Weight loss through diet and exercise is the most appropriate first-line lifestyle therapy in polycystic ovary syndrome. Even modest weight reduction can improve insulin sensitivity, restore ovulatory cycles, lower androgen levels, and reduce metabolic risk, addressing multiple features of the syndrome simultaneously. It is recommended before or alongside pharmacologic treatments.
- A 27-year-old woman with polycystic ovary syndrome and oligomenorrhea is not seeking pregnancy and has no contraindications. Which therapy regulates her cycles and protects the endometrium from unopposed estrogen?
- Combined oral contraceptive pills
- A copper intrauterine device
- Clomiphene citrate
- Letrozole
Correct answer: Combined oral contraceptive pills
Combined oral contraceptive pills regulate cycles and protect the endometrium from unopposed estrogen in polycystic ovary syndrome. The progestin component opposes estrogen-driven endometrial proliferation, lowering the risk of hyperplasia, while the pills also reduce androgen-related symptoms. Ovulation-induction agents would be used only when pregnancy is desired.
- A 31-year-old woman at 30 weeks gestation has preeclampsia with severe features and is being prepared for likely preterm delivery. Beyond magnesium and antihypertensives, which intervention is given specifically to benefit the fetus before delivery?
- Maternal high-dose calcium
- Prophylactic antibiotics
- Antenatal corticosteroids for fetal lung maturity
- An oral glucose load
Correct answer: Antenatal corticosteroids for fetal lung maturity
Antenatal corticosteroids for fetal lung maturity are given specifically to benefit the fetus when preterm delivery is anticipated in severe preeclampsia. These steroids accelerate surfactant production and reduce neonatal respiratory and other complications of prematurity. They complement maternal seizure prophylaxis and blood pressure control as delivery is planned.
- A 33-year-old woman is at 12 weeks gestation and asks whether anything can lower her risk of developing preeclampsia, given that she has chronic hypertension. Which preventive therapy is recommended for women at high risk?
- High-dose vitamin C and E supplementation
- Low-dose aspirin started in the late first or early second trimester
- Routine bed rest from the first trimester
- A high-sodium diet
Correct answer: Low-dose aspirin started in the late first or early second trimester
Low-dose aspirin started in the late first or early second trimester is recommended to reduce preeclampsia risk in high-risk women, such as those with chronic hypertension. It is thought to improve placental perfusion, and trials support its use in appropriate candidates. Antioxidant vitamins and routine bed rest have not been shown to prevent preeclampsia.
- A 16-year-old girl presents with cyclic lower abdominal pain each month but has never had a menstrual period, and examination shows a bulging bluish membrane at the vaginal opening with a palpable lower abdominal mass. Which condition best explains this presentation?
- Polycystic ovary syndrome
- Ovarian torsion
- Imperforate hymen with hematocolpos
- Bartholin gland abscess
Correct answer: Imperforate hymen with hematocolpos
An imperforate hymen with hematocolpos best explains cyclic pain, primary amenorrhea, and a bulging bluish vaginal membrane with a pelvic mass. The intact hymen obstructs menstrual outflow, so blood accumulates in the vagina and uterus, producing cyclic pain without visible menses. Surgical incision of the hymen relieves the obstruction.
- A 14-year-old girl has not yet had her first menstrual period but has normal breast and pubic hair development for her age. At what point is the absence of menarche generally considered primary amenorrhea warranting evaluation when secondary sexual characteristics are present?
- By age 15
- By age 11
- By age 9
- Only after age 20
Correct answer: By age 15
By age 15, the absence of menarche in a girl with normal secondary sexual characteristics is generally considered primary amenorrhea warranting evaluation. Evaluation is also indicated if there has been no breast development by about age 13 or if menses have not begun within several years of breast development. This framework helps distinguish normal variation from a disorder requiring workup.
- A 26-year-old woman who previously had regular monthly periods has now missed her menses for 4 consecutive months. Which condition is the most important to evaluate as a cause of her secondary amenorrhea before any other workup?
- Lichen sclerosus
- Pregnancy
- Bartholin cyst
- Fibroadenoma
Correct answer: Pregnancy
Pregnancy is the most important and common cause of secondary amenorrhea to evaluate first, which is why a pregnancy test is the initial step in any woman of reproductive age with absent menses. Only after pregnancy is excluded does the workup proceed to causes such as thyroid dysfunction, hyperprolactinemia, polycystic ovary syndrome, or hypothalamic dysfunction.
- A 24-year-old long-distance runner with a very low body weight has stopped menstruating, and workup shows low gonadotropin and low estrogen levels with no structural abnormality. Which mechanism best explains her amenorrhea?
- Functional hypothalamic suppression of gonadotropin-releasing hormone
- Primary ovarian failure
- An estrogen-secreting tumor
- Outflow tract obstruction
Correct answer: Functional hypothalamic suppression of gonadotropin-releasing hormone
Functional hypothalamic suppression of gonadotropin-releasing hormone best explains her amenorrhea. Excessive exercise, low energy availability, and low body weight suppress hypothalamic signaling, reducing gonadotropins and estrogen and halting menses. Restoring energy balance and weight typically reverses the suppression, distinguishing it from primary ovarian failure.
- A 28-year-old woman with galactorrhea and amenorrhea is found to have an elevated prolactin level and no pregnancy. Which underlying cause should be evaluated with pituitary imaging?
- An ovarian cyst
- A uterine fibroid
- A prolactin-secreting pituitary adenoma
- Bacterial vaginosis
Correct answer: A prolactin-secreting pituitary adenoma
A prolactin-secreting pituitary adenoma should be evaluated with pituitary imaging in a woman with galactorrhea, amenorrhea, and elevated prolactin. Excess prolactin suppresses gonadotropin-releasing hormone, causing amenorrhea, and stimulates breast milk production. Imaging identifies a prolactinoma, which is often treated with dopamine agonists rather than surgery.
- A 25-year-old woman 6 weeks after a dilation and curettage for a missed abortion has developed amenorrhea and cyclic pelvic pain, and hysteroscopy reveals intrauterine adhesions. Which condition does this represent?
- Sheehan syndrome
- Polycystic ovary syndrome
- Mullerian agenesis
- Asherman syndrome
Correct answer: Asherman syndrome
Asherman syndrome represents intrauterine adhesions, often following uterine instrumentation such as dilation and curettage. The scar tissue can obliterate part of the cavity, leading to amenorrhea, cyclic pain from trapped menstrual blood, or infertility. Hysteroscopic lysis of the adhesions is the treatment, distinguishing it from pituitary or ovarian causes of amenorrhea.
- A 34-year-old woman who had a severe postpartum hemorrhage now reports failure to lactate, fatigue, and amenorrhea months later. Which condition involving ischemic injury to the pituitary best explains these findings?
- Asherman syndrome
- Sheehan syndrome
- Graves disease
- Polycystic ovary syndrome
Correct answer: Sheehan syndrome
Sheehan syndrome best explains failure to lactate, fatigue, and amenorrhea after a severe postpartum hemorrhage. Hypotension from massive blood loss can cause ischemic necrosis of the enlarged pituitary gland, leading to deficiencies of prolactin, gonadotropins, and other hormones. The inability to breastfeed is often the earliest clue.
- A 29-year-old woman desiring pregnancy is tracking her cycle. In relation to the luteinizing hormone surge, when does ovulation typically occur?
- About 24 to 36 hours after the luteinizing hormone surge
- Immediately at the start of menses
- Two weeks after the next expected period
- Only after progesterone peaks late in the luteal phase
Correct answer: About 24 to 36 hours after the luteinizing hormone surge
Ovulation occurs about 24 to 36 hours after the onset of the luteinizing hormone surge. The mid-cycle surge triggers final follicular maturation and release of the egg, which is the basis for ovulation predictor kits that detect the surge. Timing intercourse around this window optimizes the chance of conception.
- A 26-year-old woman asks which hormone, secreted by the corpus luteum after ovulation, maintains the endometrium during the luteal phase. Which hormone is this?
- Follicle-stimulating hormone
- Luteinizing hormone
- Progesterone
- Estrogen alone
Correct answer: Progesterone
Progesterone, secreted by the corpus luteum after ovulation, maintains the endometrium during the luteal phase. It stabilizes and prepares the secretory endometrium for possible implantation, and if pregnancy does not occur, the corpus luteum regresses and falling progesterone triggers menstruation. This central role makes progesterone the key luteal-phase hormone.
- A 32-year-old woman with heavy menstrual bleeding wants a treatment that reduces bleeding and provides contraception while sparing the uterus. Which option directly thins the endometrium and decreases menstrual blood loss?
- A copper intrauterine device
- The levonorgestrel-releasing intrauterine device
- Tubal ligation
- A barrier method
Correct answer: The levonorgestrel-releasing intrauterine device
The levonorgestrel-releasing intrauterine device directly thins the endometrium and decreases menstrual blood loss while providing contraception and sparing the uterus. Its local progestin suppresses endometrial growth, making it a first-line treatment for heavy menstrual bleeding. A copper device, by contrast, can increase menstrual flow.
- A 19-year-old woman with primary dysmenorrhea wants relief from her painful periods. Which medication class is first-line because it reduces the prostaglandins responsible for the painful uterine contractions?
- Oral antibiotics
- Proton pump inhibitors
- Antihistamines
- Nonsteroidal anti-inflammatory drugs
Correct answer: Nonsteroidal anti-inflammatory drugs
Nonsteroidal anti-inflammatory drugs are first-line for primary dysmenorrhea because they inhibit prostaglandin production. Excess prostaglandins drive the strong uterine contractions and ischemia that cause menstrual cramps, so reducing them relieves pain. Combined hormonal contraceptives are another effective option, especially when contraception is also desired.
- A 30-year-old woman seeking preconception counseling asks what supplement she should begin before pregnancy to reduce the risk of fetal neural tube defects. Which recommendation is correct?
- Folic acid started before conception
- Vitamin A in high doses
- Iron only after the second trimester
- Calcium beginning at delivery
Correct answer: Folic acid started before conception
Folic acid started before conception is recommended to reduce the risk of fetal neural tube defects. Because the neural tube closes very early in pregnancy, often before a woman knows she is pregnant, beginning supplementation preconceptionally ensures adequate folate during this critical window. Women with prior affected pregnancies require higher doses.
- A 29-year-old woman at 28 weeks gestation who is Rh-negative with an Rh-positive partner is seen for routine care. Which intervention is given at this point to prevent maternal alloimmunization?
- A blood transfusion
- High-dose corticosteroids
- A routine antepartum dose of anti-D immune globulin
- Empiric antibiotics
Correct answer: A routine antepartum dose of anti-D immune globulin
A routine antepartum dose of anti-D immune globulin is given around 28 weeks to an unsensitized Rh-negative woman to prevent maternal alloimmunization. It neutralizes any fetal Rh-positive cells that cross into the maternal circulation before delivery, reducing the risk of hemolytic disease in this and future pregnancies. Another dose is given after delivery if the newborn is Rh-positive.
- A 25-year-old woman at 18 weeks gestation has a markedly elevated maternal serum alpha-fetoprotein on screening. Which fetal condition is most associated with this finding?
- Trisomy 21
- An open neural tube defect
- Gestational diabetes
- Placenta previa
Correct answer: An open neural tube defect
An open neural tube defect is most associated with a markedly elevated maternal serum alpha-fetoprotein. Leakage of this fetal protein through an open defect such as spina bifida or anencephaly raises maternal levels, prompting detailed ultrasound. In contrast, low alpha-fetoprotein is associated with certain aneuploidies such as trisomy 21.
- A 31-year-old woman at 39 weeks gestation is being assessed for readiness for labor induction. Which scoring system uses cervical dilation, effacement, consistency, position, and fetal station to predict the likelihood of successful induction?
- The Apgar score
- The Gleason score
- The Bishop score
- The Bethesda system
Correct answer: The Bishop score
The Bishop score uses cervical dilation, effacement, consistency, position, and fetal station to predict the likelihood of a successful labor induction. A higher score indicates a more favorable cervix and a greater chance that induction will lead to vaginal delivery, while a low score may prompt cervical ripening first. The Apgar score assesses the newborn, not the cervix.
- A 27-year-old woman in labor has a fetal heart rate tracing showing recurrent late decelerations after contractions. Which physiologic process do late decelerations most often reflect?
- Head compression
- Fetal sleep cycles
- Maternal fever alone
- Uteroplacental insufficiency
Correct answer: Uteroplacental insufficiency
Late decelerations most often reflect uteroplacental insufficiency. The gradual drop in fetal heart rate that begins after the contraction peak suggests impaired oxygen delivery across the placenta during contractions, which is concerning for fetal hypoxia. Management focuses on improving perfusion, such as repositioning, fluids, and oxygen, and considering expedited delivery if persistent.
- A 25-year-old woman in labor has a fetal tracing with variable decelerations that vary in timing and shape. Which cause is most characteristic of variable decelerations?
- Uteroplacental insufficiency
- Umbilical cord compression
- Maternal hyperglycemia
- Fetal anemia alone
Correct answer: Umbilical cord compression
Umbilical cord compression is most characteristic of variable decelerations. Their abrupt, variable onset and recovery reflect transient compression of the cord, often related to fetal movement or low amniotic fluid. Repositioning the mother frequently relieves the compression, and amnioinfusion may help when oligohydramnios contributes.
- A 30-year-old woman delivers a newborn, and the infant is assessed at 1 and 5 minutes of life. Which five components make up the score used for this assessment?
- Heart rate, respiratory effort, muscle tone, reflex irritability, and color
- Weight, length, head circumference, temperature, and glucose
- Dilation, effacement, station, consistency, and position
- Hemoglobin, platelets, sodium, glucose, and pH
Correct answer: Heart rate, respiratory effort, muscle tone, reflex irritability, and color
Heart rate, respiratory effort, muscle tone, reflex irritability, and color make up the Apgar score used to assess the newborn at 1 and 5 minutes of life. Each component is scored and summed to give a rapid picture of the infant's transition and need for resuscitation. It evaluates the neonate rather than the cervix or maternal labs.
- A 24-year-old woman is determining her due date and reports a reliable last menstrual period. Using Naegele rule, how is the estimated date of delivery calculated from the first day of the last menstrual period?
- Add 7 days and subtract 3 months, then adjust the year
- Add 3 days and subtract 7 months
- Subtract 7 days and add 1 month
- Add 2 weeks to the conception date only
Correct answer: Add 7 days and subtract 3 months, then adjust the year
Naegele rule calculates the estimated date of delivery by adding 7 days to the first day of the last menstrual period and subtracting 3 months, adjusting the year as needed. This approximates a 40-week gestation from the last menstrual period in a woman with regular 28-day cycles. Ultrasound dating is used when the menstrual history is uncertain.
- A 28-year-old pregnant woman wants to know when her uterus will be felt at a recognizable landmark. At approximately what gestational age does the uterine fundus typically reach the level of the umbilicus?
- About 8 weeks
- About 20 weeks
- About 32 weeks
- About 40 weeks
Correct answer: About 20 weeks
The uterine fundus typically reaches the level of the umbilicus at about 20 weeks of gestation. After about 20 weeks, the fundal height in centimeters roughly corresponds to the number of weeks of gestation in a normally growing pregnancy. This landmark helps clinicians estimate gestational age and monitor fetal growth.
- A 26-year-old woman at 16 weeks gestation undergoes amniocentesis for genetic testing. Which complication is the procedure most associated with, and how should she be counseled?
- A high risk of immediate labor every time
- Guaranteed fetal infection
- A small risk of pregnancy loss
- No risk of any complication
Correct answer: A small risk of pregnancy loss
Amniocentesis is most associated with a small risk of pregnancy loss, and the patient should be counseled accordingly. The procedure samples amniotic fluid for diagnostic genetic testing, and although generally safe, it carries a low procedure-related risk of miscarriage along with rare risks of infection or leakage. This informs the decision to pursue diagnostic versus screening testing.
- A 25-year-old pregnant woman is found to have asymptomatic bacteriuria on a routine prenatal urine culture. Why is this treated in pregnancy even though she has no symptoms?
- To prevent progression to pyelonephritis and preterm birth
- Because it always indicates a sexually transmitted infection
- To stop ongoing vaginal bleeding
- To correct anemia of pregnancy
Correct answer: To prevent progression to pyelonephritis and preterm birth
Asymptomatic bacteriuria is treated in pregnancy to prevent progression to pyelonephritis and the associated risks of preterm birth and low birth weight. Physiologic urinary changes in pregnancy raise the chance that untreated bacteriuria will ascend to the kidneys, so screening and treatment are standard prenatal care even without symptoms.
- A 24-year-old woman at 6 weeks gestation asks why she has nausea and breast tenderness. Which hormone produced by the placenta is primarily responsible for early pregnancy symptoms and is detected by pregnancy tests?
- Human chorionic gonadotropin
- Follicle-stimulating hormone
- Cortisol
- Aldosterone
Correct answer: Human chorionic gonadotropin
Human chorionic gonadotropin, produced by the placental trophoblast, is primarily responsible for many early pregnancy symptoms such as nausea and is the hormone detected by pregnancy tests. Its rapid early rise supports the corpus luteum and progesterone production until the placenta takes over. Its level also helps assess the progress of an early pregnancy.
- A 22-year-old woman presents with a painless, beefy-red, friable ulcer on the vulva that bleeds easily, acquired in a region where the infection is endemic. Which sexually transmitted infection is most consistent with this lesion?
- Primary syphilis
- Granuloma inguinale, also called donovanosis
- Genital herpes
- Vulvovaginal candidiasis
Correct answer: Granuloma inguinale, also called donovanosis
Granuloma inguinale, also called donovanosis, is most consistent with a painless, beefy-red, friable genital ulcer that bleeds easily and is acquired in endemic regions. It is caused by Klebsiella granulomatis and diagnosed by Donovan bodies on tissue smear. Its painless, vascular ulcer differs from the tender ulcers of herpes and chancroid.
- A 21-year-old woman presents with one or more painful genital ulcers with ragged, undermined borders and very tender, suppurative inguinal lymphadenopathy. Which sexually transmitted infection caused by Haemophilus ducreyi is most likely?
- Primary syphilis
- Lymphogranuloma venereum
- Chancroid
- Genital warts
Correct answer: Chancroid
Chancroid is most likely given painful genital ulcers with ragged, undermined borders and tender, suppurative inguinal lymphadenopathy. Caused by Haemophilus ducreyi, it produces deep, soft, painful ulcers, in contrast to the painless, indurated chancre of syphilis. The painful ulcer with painful buboes is the key distinguishing feature.
- A 27-year-old woman who delivered 2 weeks ago presents with persistent low mood, anhedonia, poor sleep beyond newborn-related disruption, and feelings of worthlessness that have lasted most of the day for over 2 weeks. Which diagnosis best fits, in contrast to a milder, self-limited mood change?
- Postpartum blues
- Postpartum depression
- Postpartum psychosis
- Generalized anxiety disorder
Correct answer: Postpartum depression
Postpartum depression best fits persistent depressive symptoms lasting more than 2 weeks with functional impairment after delivery. Unlike postpartum blues, which are mild and resolve within about 2 weeks, postpartum depression is more severe and prolonged and requires treatment such as therapy and antidepressants. It lacks the psychotic features that define postpartum psychosis.
- A 32-year-old woman with regular cycles and a normal partner semen analysis is undergoing infertility evaluation. Which test is used to assess whether her fallopian tubes are patent?
- Endometrial biopsy
- Serum prolactin
- Hysterosalpingography
- Pelvic plain radiograph
Correct answer: Hysterosalpingography
Hysterosalpingography is used to assess fallopian tube patency in an infertility evaluation. Contrast is instilled into the uterus and tubes under fluoroscopy, and spillage into the peritoneal cavity confirms patency, while a blockage suggests a tubal cause of infertility. It also outlines the uterine cavity to detect structural abnormalities.
- A 24-year-old woman near the time of expected ovulation reports a change in her cervical mucus. Which mucus characteristic is most consistent with peak fertility around ovulation?
- Thick, opaque, and scant mucus
- Completely absent mucus
- Bloody mucus only
- Clear, thin, stretchy mucus resembling raw egg white
Correct answer: Clear, thin, stretchy mucus resembling raw egg white
Clear, thin, stretchy mucus resembling raw egg white is most consistent with peak fertility around ovulation. Rising estrogen makes the cervical mucus more abundant, slippery, and stretchable to facilitate sperm transport, a sign used in fertility awareness methods. After ovulation, progesterone thickens the mucus again.
- A 30-year-old woman experiencing recurrent pregnancy loss is being evaluated. Which definition is generally used to define recurrent pregnancy loss prompting an evaluation?
- A single first-trimester miscarriage
- Two or more consecutive pregnancy losses
- Loss only after 24 weeks
- Any episode of first-trimester bleeding
Correct answer: Two or more consecutive pregnancy losses
Two or more consecutive pregnancy losses is generally used to define recurrent pregnancy loss prompting evaluation. At this threshold, investigation for causes such as anatomic, genetic, endocrine, and antiphospholipid antibody factors becomes worthwhile. A single early miscarriage is common and usually does not by itself warrant a full workup.
- A 33-year-old woman with recurrent second-trimester pregnancy losses and a history of arterial and venous clots is found to have antiphospholipid antibodies. Which intervention is used in subsequent pregnancies to improve outcomes?
- High-dose vitamin D alone
- Low-dose aspirin combined with heparin
- Routine bed rest only
- A copper intrauterine device
Correct answer: Low-dose aspirin combined with heparin
Low-dose aspirin combined with heparin is used in subsequent pregnancies in women with antiphospholipid syndrome to improve outcomes. This anticoagulation strategy counteracts the prothrombotic state that causes placental thrombosis and pregnancy loss. Identifying the antibodies and providing this therapy can substantially improve live-birth rates.
- A 26-year-old woman who delivered yesterday is breastfeeding for the first time, and her infant is receiving a thick, yellowish first milk. Which substance is this early breast secretion, and why is it valuable to the newborn?
- Lochia, which is uterine discharge
- Amniotic fluid retained in the breast
- Colostrum, which is rich in protective antibodies
- Meconium expressed from the breast
Correct answer: Colostrum, which is rich in protective antibodies
Colostrum is the thick, yellowish first milk, and it is valuable because it is rich in protective antibodies, especially immunoglobulin A. This early secretion provides passive immunity and nutrients tailored to the newborn before mature milk comes in. Encouraging early breastfeeding ensures the infant receives these benefits.
- A 35-year-old woman undergoing fertility treatment with ovarian stimulation develops abdominal distension, ascites, and ovarian enlargement after egg retrieval. Which iatrogenic complication is most likely?
- Mittelschmerz
- Bacterial vaginosis
- Ovarian torsion from a normal ovary
- Ovarian hyperstimulation syndrome
Correct answer: Ovarian hyperstimulation syndrome
Ovarian hyperstimulation syndrome is most likely after ovarian stimulation, presenting with enlarged ovaries, abdominal distension, and fluid shifts such as ascites. It results from increased vascular permeability triggered by the stimulation and human chorionic gonadotropin, and severe cases can cause hemoconcentration and thrombosis. Recognizing it guides supportive management and monitoring.
- A 23-year-old woman with mild lower abdominal pain has a positive pregnancy test and a serum beta-hCG that, when repeated 48 hours later, has risen by only 20 percent. She is stable with no intrauterine pregnancy seen on ultrasound. How should this abnormal beta-hCG rise be interpreted?
- It confirms a healthy intrauterine pregnancy
- It is consistent with an abnormal pregnancy such as an ectopic
- It rules out pregnancy
- It indicates twins
Correct answer: It is consistent with an abnormal pregnancy such as an ectopic
A beta-hCG that rises by only about 20 percent over 48 hours is consistent with an abnormal pregnancy such as an ectopic or a failing intrauterine pregnancy. A normally developing early intrauterine pregnancy typically rises by at least roughly 50 percent in this interval, so a subnormal rise without a visible intrauterine pregnancy warrants close follow-up to localize and characterize the pregnancy.
- A 50-year-old woman near menopause asks which laboratory change reflects declining ovarian reserve as she transitions. Which hormonal trend is characteristic of the perimenopausal and postmenopausal years?
- A progressive fall in follicle-stimulating hormone
- A progressive rise in follicle-stimulating hormone
- A sustained rise in estradiol
- A sustained rise in progesterone
Correct answer: A progressive rise in follicle-stimulating hormone
A progressive rise in follicle-stimulating hormone is characteristic of the perimenopausal and postmenopausal years. As the ovarian follicle pool is depleted and produces less estradiol and inhibin, the loss of negative feedback allows the pituitary to release more follicle-stimulating hormone. This rising level reflects the declining ovarian reserve of the menopausal transition.
- A patient who reads only at a third-grade level is handed a dense, jargon-filled consent form before a colonoscopy. To make the consent process valid, what should the PA do?
- Have the patient sign quickly so the schedule stays on time
- Ask a family member to sign on the patient's behalf
- Skip the discussion because a signed form is sufficient
- Explain the information in plain language the patient can understand and confirm comprehension
Correct answer: Explain the information in plain language the patient can understand and confirm comprehension
Explaining the information in plain, understandable language and confirming the patient comprehends it is correct, because informed consent requires actual understanding, not merely a signature on a complex document. Rushing a signature defeats comprehension, a competent adult's consent cannot be delegated to a relative, and a signed form without understanding is not valid consent.
- A PA is treating a patient who speaks only Vietnamese and is obtaining consent for a procedure. Which step best supports a valid, ethical consent process?
- Use the patient's young child to translate the risks
- Proceed in English and document that the patient nodded
- Postpone consent indefinitely until the patient learns English
- Use a qualified medical interpreter to convey the information
Correct answer: Use a qualified medical interpreter to convey the information
Using a qualified medical interpreter is correct because the patient must receive the disclosure in a language he genuinely understands for consent to be informed and voluntary. Relying on a child risks inaccuracy and places an inappropriate burden on the minor, proceeding in a language the patient does not understand invalidates consent, and indefinite postponement denies needed care.
- During an emergency, an unconscious trauma patient with no surrogate present requires an immediate life-saving operation. Under what doctrine may the team proceed without formal consent?
- Emergency (implied) consent when delay would threaten life or limb
- Therapeutic privilege exercised for convenience
- Substituted judgment by the on-call administrator
- Mandatory waiver of all patient rights during emergencies
Correct answer: Emergency (implied) consent when delay would threaten life or limb
Emergency, or implied, consent permits necessary life- or limb-saving treatment for an incapacitated patient when no surrogate is available and delay would cause serious harm, making it correct. Therapeutic privilege is a narrow exception about withholding information, an administrator does not provide substituted judgment, and emergencies do not waive all patient rights.
- A PA wants to confirm that a patient truly has decision-making capacity before a high-risk consent. Which four abilities should the PA assess?
- Reading speed, vocabulary, memory, and politeness
- Understanding, appreciation, reasoning, and the ability to communicate a choice
- Income, insurance status, age, and education
- Agreement with the PA, calmness, trust, and gratitude
Correct answer: Understanding, appreciation, reasoning, and the ability to communicate a choice
Decision-making capacity is assessed by whether the patient can understand the information, appreciate how it applies to her situation, reason through the options, and communicate a stable choice, which is the correct set. Reading speed, demographics, and emotional agreement with the clinician are not the criteria that define capacity.
- A PA chooses an effective antibiotic that is known to be the least toxic of several reasonable options for a patient with multiple comorbidities. Which ethical principle does this choice most directly reflect?
- Justice
- Veracity
- Nonmaleficence
- Autonomy
Correct answer: Nonmaleficence
Nonmaleficence, the duty to avoid causing harm captured by the maxim first, do no harm, is most directly reflected when the clinician selects the least toxic effective option, making it correct. Justice concerns fair allocation, veracity concerns truth-telling, and autonomy concerns the patient's own choices rather than minimizing harm.
- A new clinic policy assigns scarce appointment slots strictly by medical urgency rather than by ability to pay. This policy most clearly embodies which bioethical principle?
- Beneficence
- Justice
- Confidentiality
- Veracity
Correct answer: Justice
Justice, which concerns the fair and equitable distribution of limited health-care resources, is most clearly embodied by allocating appointments according to medical need rather than wealth, making it correct. Beneficence is acting for the patient's good, confidentiality protects information, and veracity is honesty, none of which describe fair resource allocation.
- A patient asks the PA, point blank, whether a recently ordered biopsy confirmed cancer, and it did. The patient appears anxious but stable. Which ethical principle obligates the PA to answer honestly?
- Autonomy
- Nonmaleficence
- Justice
- Veracity
Correct answer: Veracity
Veracity, the duty to tell the truth, obligates the PA to answer honestly about the biopsy result, which is correct because patients have a right to truthful information about their own health. Autonomy is the right to decide, nonmaleficence is avoiding harm, and justice is fair allocation, none of which is the specific duty to be truthful.
- When a patient's right to make her own choices conflicts with the clinician's desire to act in what he believes is her best interest, this tension is best described as a conflict between which two principles?
- Autonomy and beneficence
- Justice and veracity
- Confidentiality and nonmaleficence
- Fidelity and distributive justice
Correct answer: Autonomy and beneficence
A clash between the patient's self-determination and the clinician's wish to do what he thinks is best is the classic conflict between autonomy and beneficence, making it correct. Justice and veracity, confidentiality and nonmaleficence, and fidelity and distributive justice describe different ethical tensions not at play in this specific scenario.
- A PA discovers that a coworker has been viewing the electronic chart of a neighbor who is not under that coworker's care, purely out of curiosity. What does this access represent?
- A permissible quality-improvement review
- An impermissible breach of patient confidentiality
- A required step in care coordination
- An acceptable use because both work at the facility
Correct answer: An impermissible breach of patient confidentiality
Accessing a patient's record without a treatment, payment, or operations purpose is an impermissible breach of confidentiality, making it correct. Curiosity is not quality improvement, it is not part of legitimate care coordination, and merely working at the facility does not authorize access to records of patients one is not caring for.
- A law-enforcement officer arrives at the clinic and demands a patient's full medical record without a warrant, subpoena, or the patient's authorization. What is the most appropriate response under privacy rules?
- Release the entire record because police requested it
- Provide a verbal summary to avoid creating a paper trail
- Hand over the record only if the patient is a suspect
- Decline to release records absent valid legal authority or patient authorization
Correct answer: Decline to release records absent valid legal authority or patient authorization
Declining to release records without valid legal process or patient authorization is correct, because privacy rules generally require a warrant, court order, or authorization before disclosing protected health information to law enforcement. A bare request does not justify release, a verbal summary is still an impermissible disclosure, and suspect status alone does not waive privacy protections.
- Under the minimum necessary standard, when a billing clerk needs information to process a claim, what should be shared?
- The entire medical record for completeness
- Nothing, because billing staff may never see clinical data
- All records of every family member on the same plan
- Only the information reasonably necessary for the billing task
Correct answer: Only the information reasonably necessary for the billing task
Sharing only the information reasonably necessary to accomplish the billing task is correct, because the minimum necessary standard limits disclosure to what is needed for the purpose. Releasing the entire record exceeds that limit, withholding all data would prevent legitimate payment operations, and other family members' records are irrelevant to one patient's claim.
- A clinic suffers a breach in which unencrypted laptops containing patient data are stolen. Beyond securing data, what obligation does breach notification generally impose?
- Notifying affected individuals that their information was compromised
- Immediately destroying all remaining copies of the records
- Refusing to acknowledge the breach to avoid alarm
- Charging patients a fee to learn whether they were affected
Correct answer: Notifying affected individuals that their information was compromised
Notifying the affected individuals that their protected health information was compromised is the correct obligation imposed by breach-notification requirements. Destroying remaining records would be improper, concealing the breach violates the duty to notify, and patients cannot be charged to find out whether their own data was exposed.
- A patient is competent and explicitly asks that her diagnosis not be shared with her adult son who often accompanies her. What should the PA do at the next visit when the son is present?
- Discuss the diagnosis openly since the son is family
- Tell the son privately afterward to keep him informed
- Document that family always has a right to the information
- Honor the patient's request and not disclose to the son without her permission
Correct answer: Honor the patient's request and not disclose to the son without her permission
Honoring the competent patient's explicit request not to share information with her son is correct, because the patient controls disclosure of her own protected health information. Family status does not override her wishes, telling the son privately still breaches confidentiality, and family members do not have an automatic right to a competent adult's medical information.
- A PA wants to know how well a test performs at correctly classifying patients who actually have the disease. Which calculation answers this?
- True negatives divided by all who are positive
- Positives divided by the total population
- True positives divided by all who have the disease
- False positives divided by true negatives
Correct answer: True positives divided by all who have the disease
Sensitivity is true positives divided by all people who actually have the disease, which is the correct measure of how well a test identifies diseased patients. True negatives over positives is not a defined standard metric, positives over the whole population approximates prevalence of positives, and false positives over true negatives describes the false-positive rate, not detection of true cases.
- A clinician wants the probability that a patient with a negative result truly does not have the disease. Which value provides this?
- Sensitivity
- Absolute risk reduction
- Specificity
- Negative predictive value
Correct answer: Negative predictive value
Negative predictive value is the probability that a person with a negative test truly does not have the disease, making it correct. Sensitivity measures detection among the diseased, specificity measures correct classification among the healthy, and absolute risk reduction is a treatment-effect measure unrelated to interpreting a single test result.
- A PA reads that an exposure is associated with an odds ratio of 3.0 for a disease, with a 95% confidence interval of 1.5 to 6.0. How should this be interpreted?
- The exposure is protective against the disease
- The association is statistically significant and suggests increased odds of disease
- The result is not significant because the odds ratio exceeds 1.0
- The odds of disease are identical in exposed and unexposed groups
Correct answer: The association is statistically significant and suggests increased odds of disease
An odds ratio of 3.0 with a confidence interval that lies entirely above 1.0 indicates a statistically significant association with higher odds of disease in the exposed, which is correct. An odds ratio above 1.0 suggests increased risk rather than protection, exceeding 1.0 does not make a result nonsignificant, and identical odds would require an odds ratio of 1.0.
- A study comparing mean blood pressures between two groups reports a p-value of 0.45 at a preset significance level of 0.05. What is the correct conclusion?
- The difference is statistically significant
- The study proves there is no difference
- The result fails to reach statistical significance
- The p-value indicates the size of the effect
Correct answer: The result fails to reach statistical significance
A p-value of 0.45, far above the 0.05 threshold, means the result fails to reach statistical significance, which is correct. A nonsignificant result does not prove no difference exists, it is not significant despite the wording of the first option, and a p-value reflects the probability of the data under the null hypothesis, not the magnitude of the effect.
- An investigator concludes a drug works because a p-value crossed 0.05, even though the actual difference in outcomes was clinically trivial. This scenario best illustrates which distinction?
- The difference between sensitivity and specificity
- The difference between statistical significance and clinical significance
- The difference between incidence and prevalence
- The difference between a cohort and a case-control study
Correct answer: The difference between statistical significance and clinical significance
A statistically significant but clinically trivial result illustrates the distinction between statistical significance and clinical significance, which is correct, because a small p-value does not guarantee a meaningful effect. Sensitivity versus specificity, incidence versus prevalence, and study-design contrasts are unrelated to this particular issue.
- A PA wants to study whether a rare exposure is linked to a common chronic disease by starting with diseased and non-diseased patients and looking backward at exposures. Which study design is this?
- Randomized controlled trial
- Prospective cohort study
- Case-control study
- Systematic review
Correct answer: Case-control study
Selecting subjects on the basis of disease status and then comparing prior exposures is a case-control study, which is correct and especially efficient for studying associations retrospectively. A randomized controlled trial assigns interventions, a prospective cohort follows exposed and unexposed groups forward in time, and a systematic review synthesizes existing studies rather than enrolling subjects.
- Researchers follow a group of exposed and unexposed healthy individuals over ten years to compare who develops heart disease. Which study design does this describe?
- Cohort study
- Case-control study
- Cross-sectional study
- Case report
Correct answer: Cohort study
Following exposed and unexposed people forward over time to observe who develops the outcome defines a cohort study, which is correct. A case-control study works backward from outcome to exposure, a cross-sectional study captures a single point in time, and a case report describes an individual patient rather than tracking a population.
- In a study of a new analgesic, neither the patients nor the clinicians assessing pain know who received the active drug or placebo. What is the primary purpose of this double-blinding?
- To increase the sample size of the trial
- To raise the disease prevalence in the study group
- To reduce bias in the reporting and assessment of outcomes
- To eliminate the need for a control group
Correct answer: To reduce bias in the reporting and assessment of outcomes
Double-blinding reduces bias by keeping both participants and assessors unaware of group assignment, which is correct because expectations cannot then distort how outcomes are reported or measured. Blinding does not change sample size, does not alter prevalence, and does not remove the need for a control group, which remains essential for comparison.
- A trial analyzes participants according to the group to which they were originally randomized, even if some did not complete the assigned treatment. Which analytic approach is this?
- Per-protocol analysis
- Subgroup analysis
- Intention-to-treat analysis
- Post hoc analysis
Correct answer: Intention-to-treat analysis
Analyzing participants by their original randomized assignment regardless of adherence is intention-to-treat analysis, which is correct because it preserves randomization and reflects real-world effectiveness. Per-protocol analysis includes only those who completed the protocol, subgroup analysis examines portions of the sample, and post hoc analysis is unplanned analysis done after the fact.
- A PA reads about a new screening program where five-year survival appears longer simply because the disease was detected earlier without changing the time of death. Which bias does this illustrate?
- Recall bias
- Lead-time bias
- Confounding by indication
- Publication bias
Correct answer: Lead-time bias
Lead-time bias occurs when earlier detection lengthens apparent survival time without actually prolonging life, which is correct. Recall bias arises from differential memory of exposures, confounding by indication relates to why a treatment was chosen, and publication bias concerns the selective publishing of positive results, none of which explains survival inflated purely by earlier diagnosis.
- A meta-analysis is suspected to overstate a drug's benefit because trials with negative results were never published and could not be included. Which bias is most responsible?
- Lead-time bias
- Publication bias
- Spectrum bias
- Hawthorne effect
Correct answer: Publication bias
Publication bias, the tendency for studies with positive or significant results to be published more often than negative ones, is most responsible for an inflated pooled estimate, making it correct. Lead-time bias relates to early detection, spectrum bias affects test-accuracy across patient mixes, and the Hawthorne effect describes behavior change from being observed.
- Before drawing up a high-alert medication, a nurse asks a second clinician to verify the drug, dose, and patient. What patient-safety strategy does this independent double-check represent?
- A redundancy to catch errors before they reach the patient
- An unnecessary delay that should be eliminated
- A method to assign blame after an error
- A billing verification step
Correct answer: A redundancy to catch errors before they reach the patient
An independent double-check is a built-in redundancy designed to catch medication errors before they reach the patient, which is correct. It is not a needless delay given the high-alert risk, it is a preventive rather than blame-assigning measure, and it concerns clinical safety rather than billing verification.
- A hospital adopts computerized provider order entry with allergy and dose-range alerts after several handwriting-related prescribing errors. This intervention primarily targets which level of error prevention?
- Punishing individual prescribers who make mistakes
- Increasing the workload to slow clinicians down
- Removing all clinical decision support from prescribing
- Redesigning the system to reduce the chance of error
Correct answer: Redesigning the system to reduce the chance of error
Implementing order entry with safety alerts is a systems-level redesign that makes errors less likely, which is correct and reflects a just, system-focused safety culture. Punishing individuals addresses people rather than the system, deliberately increasing workload would not improve safety, and removing decision support would worsen rather than prevent errors.
- A patient-safety team reviews a serious adverse event using a method that asks repeated why questions to trace a problem back to its underlying systemic origins. What is this technique commonly called?
- The five whys technique
- A randomized crossover design
- Therapeutic privilege
- A confidence-interval analysis
Correct answer: The five whys technique
The five whys technique repeatedly asks why to drill down from a surface problem to its root systemic cause, which is correct in the context of root cause analysis. A randomized crossover design is a trial structure, therapeutic privilege is an ethics concept about withholding information, and confidence-interval analysis is a statistical method, none of which describes this iterative questioning approach.
- A PA evaluates an alert, oriented older adult who arrives with bruises in unusual patterns, untreated pressure ulcers, and signs of neglect by a caregiver. What is the PA's appropriate action?
- Do nothing because the patient has not complained
- Discharge the patient back to the caregiver without comment
- Report suspected elder abuse or neglect to the appropriate agency
- Confront the caregiver and demand an apology
Correct answer: Report suspected elder abuse or neglect to the appropriate agency
Reporting suspected elder abuse or neglect to the appropriate adult protective agency is correct, because clinicians are mandated reporters of reasonable suspicion of harm to vulnerable adults. Inaction abandons a patient at risk, returning the patient to a suspected abuser without intervention is unsafe, and confronting the caregiver does not fulfill the legal reporting duty.
- A PA assesses an adult patient who appears to be the victim of intimate partner violence but is competent and explicitly declines any report or intervention. What is generally the most appropriate response?
- Report the abuse to police regardless of the patient's wishes
- Refuse to treat the patient until she agrees to leave the partner
- Respect the competent adult's choice while offering resources and documenting findings
- Tell the partner what the patient disclosed
Correct answer: Respect the competent adult's choice while offering resources and documenting findings
Respecting a competent adult's decision while offering safety resources and documenting the findings is correct, because mandatory reporting laws for competent adult intimate partner violence vary and patient autonomy is generally preserved. Overriding her wishes, conditioning care on leaving the partner, and disclosing to the partner all violate autonomy or confidentiality.
- A new PA is unsure whether she may independently order a controlled substance for chronic pain in her state. Which source most authoritatively defines what she is legally permitted to do?
- The opinions of patients in the waiting room
- State law, regulations, and the practice agreement governing PA practice
- A drug manufacturer's marketing brochure
- Whatever the busiest physician verbally allows that day
Correct answer: State law, regulations, and the practice agreement governing PA practice
State law, regulations, and the collaborating or supervising practice agreement most authoritatively define a PA's permitted scope, including controlled-substance prescribing, which is correct. Patient opinions, manufacturer brochures, and informal day-to-day verbal permissions do not establish the legal boundaries of practice.
- A PA recognizes that a patient's complex condition exceeds her training and experience. Which action best fulfills her professional responsibility?
- Attempt the management alone to demonstrate competence
- Recognize her limits and refer or consult an appropriate specialist
- Discharge the patient to avoid involvement
- Tell the patient nothing can be done
Correct answer: Recognize her limits and refer or consult an appropriate specialist
Recognizing the limits of one's competence and referring or consulting an appropriate specialist is correct, because practicing within one's competence and seeking help when needed protects the patient. Attempting management beyond one's ability risks harm, discharging to avoid involvement abandons the patient, and falsely saying nothing can be done is both untrue and harmful.
- A pharmaceutical representative offers a PA an all-expenses-paid luxury trip in exchange for prescribing the company's brand more often. How should the PA view this offer?
- As an acceptable perk of clinical practice
- As a conflict of interest that should be declined
- As required continuing medical education
- As a fair reward for prescribing decisions
Correct answer: As a conflict of interest that should be declined
The offer represents a conflict of interest that should be declined, which is correct, because tying personal gifts to prescribing can bias clinical judgment and harm patients. It is not a benign perk, it is not legitimate continuing education, and rewarding prescribing decisions with gifts undermines the duty to act in the patient's best interest.
- A 17-year-old who is a parent and the sole caregiver of her own infant seeks routine medical care for herself. In many jurisdictions, on what basis may she consent to her own treatment?
- She must wait until she turns 18 for any care
- Her status as a minor parent may allow her to consent under mature- or emancipated-minor provisions
- Only her own parents can ever consent for her
- She needs written approval from her infant's other parent
Correct answer: Her status as a minor parent may allow her to consent under mature- or emancipated-minor provisions
In many jurisdictions, a minor who is herself a parent may consent to her own care under mature- or emancipated-minor provisions, which is correct. Forcing her to wait until 18 ignores those provisions, requiring her parents to consent disregards her recognized status, and the infant's other parent has no authority over her medical decisions.
- A patient's adult children disagree among themselves about whether to continue aggressive treatment for their incapacitated father, who left no advance directive. What standard should surrogates apply when his prior wishes are known?
- The best-interest standard regardless of his wishes
- The substituted-judgment standard reflecting what the patient would have wanted
- Whatever the loudest family member prefers
- The treating clinician's personal values
Correct answer: The substituted-judgment standard reflecting what the patient would have wanted
When the patient's prior wishes or values are known, surrogates should apply the substituted-judgment standard, deciding as the patient himself would have, which is correct. The best-interest standard is used when wishes are unknown, deferring to the loudest relative is not a recognized standard, and the clinician's personal values should not drive a surrogate decision.
- An incapacitated patient has never expressed any treatment preferences and left no directive, and no one knows what she would have wanted. Which standard guides surrogate decisions in this situation?
- The substituted-judgment standard
- The best-interest standard weighing benefits and burdens
- The do-not-resuscitate default
- The informed-consent waiver standard
Correct answer: The best-interest standard weighing benefits and burdens
When a patient's wishes are entirely unknown, the best-interest standard, which weighs the benefits and burdens of treatment to determine what serves the patient's welfare, applies and is correct. Substituted judgment requires knowing the patient's values, there is no automatic do-not-resuscitate default, and no informed-consent waiver standard governs surrogate decisions.
- A PA is explaining a POLST (Physician Orders for Life-Sustaining Treatment) form to a family. How does a POLST differ from a standard living will?
- A POLST is a set of actionable medical orders that travels across care settings
- A POLST applies only to healthy young adults
- A POLST replaces the need for any clinical assessment
- A POLST can be completed only after the patient dies
Correct answer: A POLST is a set of actionable medical orders that travels across care settings
A POLST is a portable set of actionable medical orders, signed by a clinician, that follows the patient across care settings, which is correct and distinguishes it from a living will that expresses general wishes. It is intended for seriously ill patients rather than healthy young adults, it does not eliminate clinical assessment, and it must be completed while the patient is alive.
- A previously appointed health-care agent under a durable power of attorney begins making decisions while the patient is still alert and fully capable of deciding for himself. When does the agent's authority typically take effect?
- Immediately upon the document being signed, overriding the patient
- Only when the patient loses decision-making capacity
- Whenever the agent decides it is convenient
- Only after the patient's death
Correct answer: Only when the patient loses decision-making capacity
A health-care agent's authority under a durable power of attorney for health care typically activates only when the patient loses decision-making capacity, which is correct, so a capable patient continues to decide for himself. The authority is not triggered merely by signing, by the agent's convenience, or after death, when the document no longer governs medical care.
- A patient with a valid advance directive specifying no intubation arrives in respiratory failure, but the directive is discovered only after intubation has already occurred. What is the most appropriate next step?
- Ignore the directive since intubation has begun
- Revisit the situation, honoring the patient's documented wishes including withdrawal of unwanted treatment
- Require the patient to write a brand-new directive while sedated
- Continue intubation indefinitely regardless of the directive
Correct answer: Revisit the situation, honoring the patient's documented wishes including withdrawal of unwanted treatment
Revisiting the situation and honoring the documented wishes, including withdrawing the unwanted intubation, is correct, because a valid directive remains binding even if treatment was started before it was found. The directive cannot be ignored simply because intubation began, a sedated patient cannot author a new directive, and continuing unwanted treatment indefinitely violates the patient's autonomy.
- A competent adult tells the PA she wants to revoke the living will she signed years ago because her values have changed. What should the PA understand about revoking an advance directive?
- A competent patient may revoke or change an advance directive at any time
- An advance directive is permanent once signed
- Only a court can revoke an advance directive
- Revocation requires the original witnesses to be present
Correct answer: A competent patient may revoke or change an advance directive at any time
A competent patient may revoke or modify an advance directive at any time, which is correct, because the directive reflects the patient's current autonomous wishes. It is not permanent once signed, it does not require a court to revoke, and the original witnesses are not needed for a competent patient to change her own directive.
- A PA reviews a diagnostic study and notes that a likelihood ratio describes how much a given test result changes the probability of disease. A positive likelihood ratio much greater than 1 indicates what?
- The positive result markedly increases the probability of disease
- The test result has no effect on disease probability
- The positive result rules the disease out
- The test is being applied to a healthy population only
Correct answer: The positive result markedly increases the probability of disease
A positive likelihood ratio much greater than 1 means a positive result substantially raises the post-test probability of disease, which is correct. A likelihood ratio near 1 indicates no useful change in probability, ruling disease out corresponds to a small negative likelihood ratio, and the likelihood ratio is a property of the test rather than a statement about which population is tested.
- A clinic is choosing which preventive intervention to fund and learns that one option has a much lower number needed to treat than another for the same outcome. What does a lower number needed to treat imply?
- Fewer patients must be treated to prevent one outcome, suggesting greater efficiency
- More patients must be harmed for each benefit
- The intervention has no measurable effect
- The disease prevalence is necessarily higher
Correct answer: Fewer patients must be treated to prevent one outcome, suggesting greater efficiency
A lower number needed to treat means fewer patients must receive the intervention to prevent one adverse outcome, indicating a more efficient benefit, which is correct. It does not describe harm, which is captured by the number needed to harm, it does not indicate a lack of effect, and it is not a direct statement about disease prevalence.
- A PA serving on a hospital ethics committee is asked to help resolve a disagreement between a patient's family and the care team about goals of care. What is the proper role of a clinical ethics consultation?
- To impose a binding legal verdict that all parties must obey
- To bill the family for arbitration services
- To take over decision-making from the patient and surrogate
- To facilitate communication and recommend an ethically supportable course of action
Correct answer: To facilitate communication and recommend an ethically supportable course of action
A clinical ethics consultation facilitates communication among the parties and recommends an ethically supportable path forward, which is correct, while leaving final decisions with the patient or surrogate and the care team. It does not issue binding legal verdicts, it is not a billing or arbitration service, and it does not seize decision-making authority from those who hold it.
