Your FREE Physician Assistant National Recertifying Exam (PANRE) Practice Test 2026 – 540+ Q&A

PANRE Practice Questions

1. A 72-year-old man with newly diagnosed nonvalvular atrial fibrillation has a CHA2DS2-VASc score of 4. He is hemodynamically stable with a heart rate of 88 beats per minute. Beyond rate control, what is the most appropriate next step?
   • Initiate an oral anticoagulant such as apixaban
   • Start low-dose aspirin 81 mg daily only
   • Schedule immediate electrical cardioversion
   • Begin clopidogrel monotherapy

   Correct answer: Initiate an oral anticoagulant such as apixaban

   Starting an oral anticoagulant such as apixaban is correct because a CHA2DS2-VASc score of 4 in a man indicates high stroke risk, for which a direct oral anticoagulant is recommended over antiplatelet therapy. Aspirin and clopidogrel are inadequate for stroke prevention in this risk tier. Cardioversion is not urgent in a stable, rate-controlled patient and would require anticoagulation or transesophageal echocardiography first.

2. In a stable patient with persistent atrial fibrillation who remains symptomatic despite adequate rate control, which strategy is most appropriate to pursue?
   • Permanent discontinuation of all anticoagulation
   • A rhythm-control strategy with antiarrhythmic drugs or catheter ablation
   • Increasing the beta-blocker until the resting heart rate is below 50
   • Routine implantation of a permanent pacemaker

   Correct answer: A rhythm-control strategy with antiarrhythmic drugs or catheter ablation

   Pursuing a rhythm-control strategy with antiarrhythmic drugs or catheter ablation is correct because patients who remain symptomatic despite adequate rate control benefit from restoration and maintenance of sinus rhythm. Stopping anticoagulation ignores ongoing stroke risk. Driving the heart rate below 50 risks bradycardia, and a pacemaker is reserved for documented bradyarrhythmia, not for symptomatic rate-controlled atrial fibrillation.

3. Which component of the CHA2DS2-VASc score is assigned 2 points rather than 1 point?
   • Hypertension
   • Diabetes mellitus
   • Prior stroke or transient ischemic attack
   • Vascular disease

   Correct answer: Prior stroke or transient ischemic attack

   Prior stroke or transient ischemic attack is correct because it is weighted 2 points in the CHA2DS2-VASc score, as is age 75 or older. Hypertension, diabetes mellitus, and vascular disease each contribute only 1 point, reflecting their lower independent stroke risk compared with a prior cerebrovascular event.

4. A 68-year-old man presents with exertional dyspnea, bilateral lower-extremity edema, and an S3 gallop. Echocardiography reveals a left ventricular ejection fraction of 30 percent. Which medication class provides a mortality benefit in this condition?
   • A dihydropyridine calcium channel blocker
   • A short-acting nitrate as monotherapy
   • An oral first-generation antihistamine
   • An angiotensin receptor-neprilysin inhibitor

   Correct answer: An angiotensin receptor-neprilysin inhibitor

   An angiotensin receptor-neprilysin inhibitor is correct because the reduced ejection fraction of 30 percent defines heart failure with reduced ejection fraction, for which guideline-directed therapy with sacubitril-valsartan reduces mortality. Dihydropyridine calcium channel blockers, nitrate monotherapy, and antihistamines provide no survival benefit in this setting.

5. Which of the following best distinguishes heart failure with preserved ejection fraction from heart failure with reduced ejection fraction?
   • A normal or near-normal left ventricular ejection fraction with signs of heart failure
   • An ejection fraction consistently below 40 percent
   • The complete absence of elevated natriuretic peptides
   • An exclusively right-sided clinical presentation

   Correct answer: A normal or near-normal left ventricular ejection fraction with signs of heart failure

   A normal or near-normal left ventricular ejection fraction with signs of heart failure is correct because preserved ejection fraction heart failure is defined by an ejection fraction of 50 percent or greater accompanied by clinical heart failure and diastolic dysfunction. An ejection fraction below 40 percent defines the reduced variant. Natriuretic peptides are typically elevated in both, and the presentation is not limited to right-sided findings.

6. A patient with chronic heart failure with reduced ejection fraction is started on a sodium-glucose cotransporter-2 inhibitor. What is the primary rationale for adding this drug class to guideline-directed therapy?
   • It is used only to lower blood glucose in diabetic patients
   • It reduces heart failure hospitalizations and cardiovascular death regardless of diabetes status
   • It rapidly reverses left ventricular hypertrophy within days
   • It serves as a first-line agent for acute pulmonary edema

   Correct answer: It reduces heart failure hospitalizations and cardiovascular death regardless of diabetes status

   Reducing heart failure hospitalizations and cardiovascular death regardless of diabetes status is correct because sodium-glucose cotransporter-2 inhibitors are now a pillar of guideline-directed therapy for reduced ejection fraction heart failure in both diabetic and nondiabetic patients. Their benefit is not limited to glycemic control, they do not acutely reverse hypertrophy, and they are not the first agents for acute pulmonary edema.

7. A 58-year-old man reports substernal chest pressure that occurs reliably after climbing two flights of stairs and resolves with several minutes of rest. He has no symptoms at rest. Which diagnosis best fits this presentation?
   • Acute ST-elevation myocardial infarction
   • Acute pericarditis
   • Stable angina pectoris
   • Aortic dissection

   Correct answer: Stable angina pectoris

   Stable angina pectoris is correct because chest pressure that is predictably provoked by exertion and relieved by rest reflects a fixed coronary stenosis with demand-related ischemia. An ST-elevation myocardial infarction produces persistent rest pain, pericarditis causes positional and pleuritic pain, and aortic dissection presents with abrupt tearing pain, none of which match this exertional, rest-relieved pattern.

8. Which medication is first-line for acute relief of an episode of stable angina?
   • Oral metoprolol
   • Subcutaneous heparin
   • Oral atorvastatin
   • Sublingual nitroglycerin

   Correct answer: Sublingual nitroglycerin

   Sublingual nitroglycerin is correct because it produces rapid coronary and systemic vasodilation to relieve an acute anginal episode within minutes. Metoprolol and atorvastatin are chronic preventive therapies that do not abort an active episode, and heparin is reserved for acute coronary syndromes rather than stable exertional angina.

9. A patient with suspected stable coronary artery disease has an intermediate pretest probability and can exercise with an interpretable baseline electrocardiogram. Which initial diagnostic test is most appropriate?
   • Exercise treadmill stress testing
   • Immediate coronary artery bypass grafting
   • Right heart catheterization
   • Twenty-four-hour ambulatory blood pressure monitoring

   Correct answer: Exercise treadmill stress testing

   Exercise treadmill stress testing is correct because a patient with intermediate pretest probability who can exercise and has an interpretable resting electrocardiogram is best evaluated with a standard treadmill stress test. Bypass grafting is a treatment, not a diagnostic step, right heart catheterization assesses filling pressures rather than ischemia, and ambulatory blood pressure monitoring evaluates hypertension rather than coronary disease.

10. According to current guidelines, which blood pressure threshold confirms a diagnosis of stage 1 hypertension on properly measured readings?
    • Systolic 120-129 and diastolic below 80 mmHg
    • Systolic 130-139 or diastolic 80-89 mmHg
    • Systolic at or above 180 or diastolic at or above 120 mmHg
    • Systolic below 120 and diastolic below 80 mmHg

    Correct answer: Systolic 130-139 or diastolic 80-89 mmHg

    Systolic 130-139 or diastolic 80-89 mmHg is correct because current ACC/AHA criteria define stage 1 hypertension at this range. A systolic of 120-129 with diastolic below 80 is elevated blood pressure, readings at or above 180/120 indicate hypertensive crisis, and values below 120/80 are normal.

11. A 55-year-old Black patient without diabetes or chronic kidney disease is diagnosed with stage 2 hypertension. Which first-line agent is most appropriate as initial monotherapy?
    • An angiotensin-converting enzyme inhibitor alone
    • A beta-blocker alone
    • A thiazide diuretic or calcium channel blocker
    • An alpha-blocker alone

    Correct answer: A thiazide diuretic or calcium channel blocker

    A thiazide diuretic or calcium channel blocker is correct because, in Black adults without heart failure or chronic kidney disease, these agents provide superior initial blood pressure lowering and cardiovascular outcomes. An angiotensin-converting enzyme inhibitor alone is less effective in this group, beta-blockers are not first-line for uncomplicated hypertension, and alpha-blockers are not recommended as initial therapy.

12. Which laboratory abnormality is a recognized adverse effect of thiazide diuretics used for hypertension?
    • Hyperkalemia
    • Hypoglycemia
    • Hypercalciuria with low serum calcium
    • Hypokalemia

    Correct answer: Hypokalemia

    Hypokalemia is correct because thiazide diuretics increase distal sodium delivery and enhance potassium excretion, commonly lowering serum potassium. They tend to raise rather than lower glucose, do not cause hyperkalemia, and actually reduce urinary calcium while modestly raising serum calcium, the opposite of the distractor offered.

13. A 64-year-old woman presents with unilateral leg swelling, calf tenderness, and warmth three days after a long flight. Which scoring tool best estimates her pretest probability for deep venous thrombosis?
    • The Wells score for deep venous thrombosis
    • The CURB-65 score
    • The CHA2DS2-VASc score
    • The Centor criteria

    Correct answer: The Wells score for deep venous thrombosis

    The Wells score for deep venous thrombosis is correct because it stratifies pretest probability using clinical features such as unilateral swelling, tenderness, and recent immobilization. CURB-65 grades pneumonia severity, CHA2DS2-VASc estimates stroke risk in atrial fibrillation, and the Centor criteria assess streptococcal pharyngitis, none of which apply to venous thrombosis.

14. In a patient with low pretest probability for deep venous thrombosis, which test result most effectively rules out the diagnosis?
    • A normal serum troponin
    • A normal D-dimer level
    • An elevated brain natriuretic peptide
    • A positive Homans sign

    Correct answer: A normal D-dimer level

    A normal D-dimer level is correct because, combined with low pretest probability, it has high negative predictive value and reliably excludes deep venous thrombosis without imaging. Troponin and brain natriuretic peptide assess myocardial injury and cardiac stretch rather than thrombosis, and the Homans sign is neither sensitive nor specific.

15. A patient is diagnosed with an acute proximal lower-extremity deep venous thrombosis without contraindication to anticoagulation. Which is the preferred initial outpatient treatment for most such patients?
    • Aspirin 81 mg daily
    • Inferior vena cava filter placement
    • A direct oral anticoagulant such as rivaroxaban
    • Compression stockings alone

    Correct answer: A direct oral anticoagulant such as rivaroxaban

    A direct oral anticoagulant such as rivaroxaban is correct because direct oral anticoagulants are first-line for most acute deep venous thrombosis and allow outpatient management without bridging in many patients. Aspirin and compression stockings alone do not adequately treat acute thrombosis, and an inferior vena cava filter is reserved for patients who cannot be anticoagulated.

16. A 60-year-old man presents with 40 minutes of crushing substernal chest pain. The electrocardiogram shows 3 mm of ST-segment elevation in leads II, III, and aVF. Which coronary artery is most likely occluded?
    • The left anterior descending artery
    • The left circumflex artery
    • The left main coronary artery
    • The right coronary artery

    Correct answer: The right coronary artery

    The right coronary artery is correct because ST elevation in the inferior leads II, III, and aVF reflects inferior wall injury, most commonly from right coronary artery occlusion. The left anterior descending supplies the anterior wall with anteroseptal changes, the circumflex affects lateral leads, and left main occlusion produces widespread changes rather than isolated inferior elevation.

17. Which finding distinguishes an ST-elevation myocardial infarction from a non-ST-elevation myocardial infarction?
    • Persistent ST-segment elevation on the electrocardiogram
    • Elevation of cardiac troponin
    • The presence of chest pain
    • A history of coronary artery disease

    Correct answer: Persistent ST-segment elevation on the electrocardiogram

    Persistent ST-segment elevation on the electrocardiogram is correct because it defines an ST-elevation myocardial infarction and signals complete coronary occlusion requiring emergent reperfusion. Troponin is elevated in both types, and chest pain and prior coronary disease are common to both and therefore cannot distinguish them.

18. A patient with an acute ST-elevation myocardial infarction presents to a hospital with on-site percutaneous coronary intervention capability. What is the preferred reperfusion strategy?
    • Observation with serial troponins for 24 hours
    • Primary percutaneous coronary intervention within the recommended time window
    • Oral anticoagulation alone without reperfusion
    • Elective stress testing in two weeks

    Correct answer: Primary percutaneous coronary intervention within the recommended time window

    Primary percutaneous coronary intervention within the recommended time window is correct because, at a percutaneous-capable hospital, prompt mechanical reperfusion is the preferred treatment for ST-elevation infarction and limits myocardial loss. Observation, anticoagulation alone, and delayed stress testing all withhold the time-sensitive reperfusion that defines optimal care.

19. A 70-year-old man has a harsh crescendo-decrescendo systolic murmur best heard at the right second intercostal space that radiates to the carotids, with a delayed and diminished carotid upstroke. Which valvular lesion is most likely?
    • Mitral regurgitation
    • Tricuspid stenosis
    • Aortic stenosis
    • Pulmonic regurgitation

    Correct answer: Aortic stenosis

    Aortic stenosis is correct because a harsh crescendo-decrescendo systolic murmur at the right upper sternal border radiating to the carotids with a slow, weak carotid upstroke is the classic presentation. Mitral regurgitation produces a holosystolic murmur at the apex, tricuspid stenosis a diastolic murmur, and pulmonic regurgitation a diastolic murmur, none matching this finding.

20. Which triad of symptoms in severe aortic stenosis indicates a poor prognosis without valve replacement?
    • Fever, chills, and night sweats
    • Polyuria, polydipsia, and weight loss
    • Cough, hemoptysis, and weight gain
    • Angina, syncope, and heart failure

    Correct answer: Angina, syncope, and heart failure

    Angina, syncope, and heart failure is correct because this classic triad in severe aortic stenosis marks symptomatic disease associated with markedly reduced survival and is an indication for aortic valve replacement. The other clusters describe infection, diabetes, and pulmonary disease and are unrelated to the natural history of aortic stenosis.

21. A patient with a holosystolic murmur heard best at the apex that radiates to the left axilla most likely has which valvular abnormality?
    • Mitral regurgitation
    • Aortic stenosis
    • Pulmonic stenosis
    • Tricuspid stenosis

    Correct answer: Mitral regurgitation

    Mitral regurgitation is correct because a holosystolic murmur loudest at the apex with radiation to the left axilla reflects retrograde flow into the left atrium. Aortic stenosis radiates to the carotids, pulmonic stenosis is a systolic ejection murmur at the left upper sternal border, and tricuspid stenosis is a diastolic murmur, none matching the described apical axillary murmur.

22. A patient with a prosthetic heart valve presents with fever, a new regurgitant murmur, and Janeway lesions. Which diagnostic framework is used to establish this diagnosis?
    • The Light criteria
    • The modified Duke criteria
    • The Ranson criteria
    • The Rome criteria

    Correct answer: The modified Duke criteria

    The modified Duke criteria is correct because they combine major and minor findings, including positive blood cultures and echocardiographic vegetations, to diagnose infective endocarditis in a febrile patient with a new murmur and embolic phenomena. The Light criteria classify pleural effusions, Ranson criteria grade pancreatitis severity, and Rome criteria define functional bowel disorders.

23. Which physical examination finding is a classic peripheral stigma of infective endocarditis?
    • Heberden nodes
    • Bouchard nodes
    • Osler nodes
    • Virchow node

    Correct answer: Osler nodes

    Osler nodes are correct because these tender violaceous lesions on the fingertips are a classic immunologic stigma of infective endocarditis. Heberden and Bouchard nodes are bony enlargements of osteoarthritis, and a Virchow node is a left supraclavicular lymph node associated with abdominal malignancy, none of which relate to endocarditis.

24. An intravenous drug user develops infective endocarditis. Which heart valve is most commonly affected in this population?
    • The aortic valve
    • The mitral valve
    • The pulmonic valve
    • The tricuspid valve

    Correct answer: The tricuspid valve

    The tricuspid valve is correct because injected pathogens enter the venous circulation and first reach the right-sided tricuspid valve, making it the most commonly involved valve in intravenous drug users. Aortic and mitral involvement predominates in non-injection endocarditis, and the pulmonic valve is rarely affected.

25. A 67-year-old smoker reports cramping calf pain that occurs after walking one block and resolves with rest. His ankle-brachial index is 0.7. Which diagnosis does this support?
    • Peripheral artery disease
    • Acute compartment syndrome
    • Deep venous thrombosis
    • Lumbar spinal stenosis

    Correct answer: Peripheral artery disease

    Peripheral artery disease is correct because reproducible exertional calf claudication relieved by rest together with an ankle-brachial index of 0.7 reflects reduced arterial perfusion. Acute compartment syndrome causes severe constant pain, deep venous thrombosis causes swelling rather than claudication, and spinal stenosis pain is typically relieved by leaning forward rather than simply stopping.

26. An ankle-brachial index of 0.85 in a patient with leg symptoms is best interpreted as indicating what?
    • Normal arterial perfusion
    • Mild peripheral artery disease
    • Noncompressible, heavily calcified arteries
    • Critical limb-threatening ischemia

    Correct answer: Mild peripheral artery disease

    Mild peripheral artery disease is correct because an ankle-brachial index between 0.71 and 0.90 indicates mild obstruction. A normal index is 0.91 to 1.40, values above 1.40 suggest noncompressible calcified vessels, and critical limb ischemia corresponds to far lower indices, often below 0.40, with rest pain or tissue loss.

27. Which intervention provides the greatest reduction in cardiovascular events for a patient with newly diagnosed peripheral artery disease who continues to smoke?
    • Daily multivitamin supplementation
    • Bed rest and leg elevation
    • Smoking cessation
    • Routine antibiotic prophylaxis

    Correct answer: Smoking cessation

    Smoking cessation is correct because tobacco is the strongest modifiable risk factor for peripheral artery disease progression and cardiovascular events, and quitting yields the largest risk reduction. Multivitamins offer no vascular benefit, bed rest and elevation worsen arterial perfusion, and antibiotic prophylaxis has no role in atherosclerotic disease.

28. A 45-year-old man is found to have a low-density lipoprotein cholesterol of 195 mg/dL on fasting lipid panel after lifestyle measures. He has no other risk factors. Which medication class is first-line to lower his cardiovascular risk?
    • A bile acid sequestrant alone
    • Niacin monotherapy
    • A fibrate alone
    • A high-intensity statin

    Correct answer: A high-intensity statin

    A high-intensity statin is correct because a low-density lipoprotein cholesterol of 190 mg/dL or higher independently warrants statin therapy, which provides the strongest evidence for reducing atherosclerotic events. Bile acid sequestrants, niacin, and fibrates are less effective at lowering low-density lipoprotein and are not first-line for this indication.

29. A patient on a statin develops diffuse muscle aches and a markedly elevated creatine kinase. What is the most appropriate next step?
    • Discontinue the statin and evaluate for myopathy
    • Double the statin dose
    • Add a second statin to the regimen
    • Ignore the symptoms and continue unchanged

    Correct answer: Discontinue the statin and evaluate for myopathy

    Discontinuing the statin and evaluating for myopathy is correct because diffuse myalgias with a markedly elevated creatine kinase suggest statin-induced muscle injury that requires stopping the drug and assessing for rhabdomyolysis. Increasing the dose or adding a second statin would worsen toxicity, and ignoring the findings risks progression to rhabdomyolysis and renal failure.

30. A 76-year-old smoker is found on imaging to have a 4.5 cm infrarenal abdominal aortic aneurysm and is asymptomatic. What is the most appropriate management?
    • Immediate open surgical repair
    • Surveillance imaging with risk-factor modification
    • Emergent endovascular repair within hours
    • Initiation of systemic thrombolysis

    Correct answer: Surveillance imaging with risk-factor modification

    Surveillance imaging with risk-factor modification is correct because an asymptomatic abdominal aortic aneurysm below 5.5 cm is monitored with serial imaging while controlling smoking and blood pressure. Surgical or endovascular repair is generally indicated at or above 5.5 cm, when rapidly enlarging, or when symptomatic, and thrombolysis has no role in aneurysm management.

31. A 70-year-old man presents with sudden severe abdominal and back pain, hypotension, and a pulsatile abdominal mass. Which diagnosis must be addressed emergently?
    • Acute gastroenteritis
    • Uncomplicated diverticulosis
    • Ruptured abdominal aortic aneurysm
    • Functional dyspepsia

    Correct answer: Ruptured abdominal aortic aneurysm

    Ruptured abdominal aortic aneurysm is correct because the triad of sudden abdominal and back pain, hypotension, and a pulsatile mass indicates a surgical emergency requiring immediate repair. Gastroenteritis, diverticulosis, and functional dyspepsia do not cause hemodynamic collapse with a pulsatile mass and are not life-threatening in this manner.

32. A 50-year-old man presents with sharp, pleuritic chest pain that improves when he leans forward, and auscultation reveals a triphasic friction rub. The electrocardiogram shows diffuse ST-segment elevation and PR-segment depression. Which diagnosis is most likely?
    • Acute anterior myocardial infarction
    • Aortic stenosis
    • Stable angina
    • Acute pericarditis

    Correct answer: Acute pericarditis

    Acute pericarditis is correct because positional pleuritic chest pain relieved by leaning forward, a friction rub, and diffuse ST elevation with PR depression are characteristic. An anterior myocardial infarction shows localized ST elevation with reciprocal changes, while aortic stenosis and stable angina do not produce a friction rub or this electrocardiographic pattern.

33. Which is the recommended first-line pharmacologic treatment for acute idiopathic pericarditis?
    • A nonsteroidal anti-inflammatory drug plus colchicine
    • High-dose systemic corticosteroids as initial therapy
    • Intravenous antibiotics for two weeks
    • Immediate anticoagulation with heparin

    Correct answer: A nonsteroidal anti-inflammatory drug plus colchicine

    A nonsteroidal anti-inflammatory drug plus colchicine is correct because this combination relieves inflammation and reduces recurrence in acute idiopathic pericarditis. Corticosteroids are reserved for refractory cases because they increase recurrence, antibiotics are unnecessary without bacterial cause, and anticoagulation can precipitate hemorrhagic effusion and is avoided.

34. A patient develops hypotension, jugular venous distention, muffled heart sounds, and pulsus paradoxus after blunt chest trauma. Which diagnosis does this clinical picture indicate?
    • Tension pneumothorax
    • Cardiac tamponade
    • Acute pulmonary embolism
    • Aortic stenosis

    Correct answer: Cardiac tamponade

    Cardiac tamponade is correct because the Beck triad of hypotension, distended neck veins, and muffled heart sounds together with pulsus paradoxus reflects pericardial fluid restricting cardiac filling. Tension pneumothorax causes tracheal deviation and absent breath sounds, pulmonary embolism does not produce muffled heart sounds, and aortic stenosis is a chronic valvular lesion.

35. What is the definitive emergent treatment for hemodynamically unstable cardiac tamponade?
    • Administration of a beta-blocker
    • High-dose loop diuretics
    • Pericardiocentesis
    • Oral colchicine

    Correct answer: Pericardiocentesis

    Pericardiocentesis is correct because removing pericardial fluid immediately relieves the impaired ventricular filling causing shock in tamponade. Beta-blockers and diuretics reduce preload and can precipitate cardiovascular collapse, and oral colchicine treats inflammatory pericarditis rather than acute tamponade physiology.

36. A patient presents with a blood pressure of 210/130 mmHg accompanied by acute confusion and papilledema. How is this presentation best classified?
    • Hypertensive urgency without organ damage
    • Elevated blood pressure
    • White-coat hypertension
    • Hypertensive emergency

    Correct answer: Hypertensive emergency

    Hypertensive emergency is correct because severe hypertension with evidence of acute target-organ damage, here encephalopathy and papilledema, defines an emergency requiring controlled parenteral blood pressure reduction. Hypertensive urgency lacks organ damage, elevated blood pressure refers to only mildly raised readings, and white-coat hypertension describes office-only elevation without crisis.

37. When treating a hypertensive emergency, what is the recommended initial goal for blood pressure reduction in the first hour for most patients?
    • Lower the mean arterial pressure by no more than about 25 percent
    • Normalize the blood pressure to below 120/80 immediately
    • Reduce the systolic pressure to 90 mmHg within minutes
    • Avoid lowering the blood pressure at all for 24 hours

    Correct answer: Lower the mean arterial pressure by no more than about 25 percent

    Lowering the mean arterial pressure by no more than about 25 percent in the first hour is correct because overly rapid reduction can cause cerebral, coronary, or renal hypoperfusion. Immediate normalization or dropping the systolic to 90 risks ischemia, and withholding treatment entirely allows ongoing organ damage in a true emergency.

38. A 30-year-old presents with palpitations and a heart rate of 180 beats per minute. The electrocardiogram shows a regular narrow-complex tachycardia without visible P waves. After vagal maneuvers fail and the patient remains stable, which medication is first-line?
    • Oral digoxin
    • Adenosine
    • Intravenous furosemide
    • Sublingual nitroglycerin

    Correct answer: Adenosine

    Adenosine is correct because a stable regular narrow-complex tachycardia consistent with paroxysmal supraventricular tachycardia is treated with adenosine after vagal maneuvers fail, transiently blocking the atrioventricular node to terminate the reentrant circuit. Digoxin acts too slowly, furosemide treats volume overload, and nitroglycerin addresses ischemia rather than the arrhythmia.

39. Which arrhythmia is characterized on the electrocardiogram by a sawtooth flutter wave pattern, classically with an atrial rate near 300 beats per minute?
    • Ventricular fibrillation
    • First-degree atrioventricular block
    • Atrial flutter
    • Sinus bradycardia

    Correct answer: Atrial flutter

    Atrial flutter is correct because the macro-reentrant atrial circuit produces a characteristic sawtooth flutter pattern with an atrial rate around 300, often conducted with regular block. Ventricular fibrillation shows chaotic disorganized activity, first-degree block shows a prolonged PR interval with normal rate, and sinus bradycardia is a slow regular sinus rhythm.

40. A monitored patient suddenly becomes pulseless, and the rhythm strip shows a chaotic, irregular waveform without identifiable QRS complexes. What is the immediate priority intervention?
    • Administration of oral aspirin
    • Synchronized cardioversion at low energy
    • Initiation of an oral beta-blocker
    • Immediate defibrillation

    Correct answer: Immediate defibrillation

    Immediate defibrillation is correct because a pulseless, chaotic, irregular rhythm indicates ventricular fibrillation, for which prompt unsynchronized defibrillation with cardiopulmonary resuscitation offers the best chance of survival. Oral aspirin and beta-blockers have no role in cardiac arrest, and synchronized cardioversion cannot synchronize to the absent organized complexes.

41. A patient's electrocardiogram shows a progressively lengthening PR interval until a QRS complex is dropped, after which the cycle repeats. Which conduction abnormality does this represent?
    • Second-degree atrioventricular block, Mobitz type I
    • Second-degree atrioventricular block, Mobitz type II
    • Third-degree (complete) heart block
    • First-degree atrioventricular block

    Correct answer: Second-degree atrioventricular block, Mobitz type I

    Second-degree atrioventricular block, Mobitz type I is correct because the progressive PR prolongation culminating in a dropped beat, known as Wenckebach, defines this pattern. Mobitz type II drops beats without progressive PR lengthening, complete heart block shows atrioventricular dissociation, and first-degree block has a consistently prolonged PR without dropped beats.

42. Which electrocardiographic finding defines third-degree (complete) atrioventricular block?
    • A fixed prolonged PR interval with every beat conducted
    • Complete dissociation between P waves and QRS complexes
    • An irregularly irregular rhythm with no P waves
    • A sawtooth atrial pattern with regular conduction

    Correct answer: Complete dissociation between P waves and QRS complexes

    Complete dissociation between P waves and QRS complexes is correct because in third-degree block the atria and ventricles depolarize independently with no conducted relationship. A fixed prolonged PR with conduction describes first-degree block, an irregularly irregular rhythm without P waves describes atrial fibrillation, and a sawtooth pattern describes atrial flutter.

43. A 24-year-old tall man with long arms and a family history of sudden cardiac death is found to have aortic root dilation. Which inherited connective tissue disorder is most associated with this cardiovascular finding?
    • Acute rheumatic fever
    • Kawasaki disease
    • Marfan syndrome
    • Takayasu arteritis

    Correct answer: Marfan syndrome

    Marfan syndrome is correct because the tall stature, arm span exceeding height, and aortic root dilation with risk of dissection are hallmark cardiovascular features of this fibrillin-1 disorder. Rheumatic fever damages valves rather than the aortic root in this pattern, and Kawasaki disease and Takayasu arteritis are inflammatory vasculitides without this connective tissue phenotype.

44. A 22-year-old collegiate athlete experiences exertional syncope, and examination reveals a systolic murmur that increases in intensity with the Valsalva maneuver. Which diagnosis is most concerning?
    • Mitral valve prolapse with regurgitation only
    • Innocent flow murmur
    • Aortic regurgitation
    • Hypertrophic cardiomyopathy

    Correct answer: Hypertrophic cardiomyopathy

    Hypertrophic cardiomyopathy is correct because exertional syncope in a young athlete with a systolic murmur that intensifies with Valsalva, which reduces preload and worsens outflow obstruction, raises concern for this leading cause of sudden cardiac death in athletes. Most other murmurs, including innocent flow murmurs and many regurgitant lesions, soften with reduced preload rather than intensifying.

45. A 35-year-old develops new heart failure several weeks after a viral upper respiratory illness, with a dilated left ventricle and reduced ejection fraction and no coronary disease. Which diagnosis is most likely?
    • Dilated cardiomyopathy from viral myocarditis
    • Hypertrophic cardiomyopathy
    • Restrictive cardiomyopathy from amyloid
    • Constrictive pericarditis

    Correct answer: Dilated cardiomyopathy from viral myocarditis

    Dilated cardiomyopathy from viral myocarditis is correct because a recent viral illness followed by ventricular dilation, systolic dysfunction, and heart failure without coronary disease points to postviral myocarditis progressing to dilated cardiomyopathy. Hypertrophic and restrictive cardiomyopathies feature thickened or stiff but nondilated ventricles, and constrictive pericarditis impairs filling without ventricular dilation.

46. A 6-year-old with poorly controlled streptococcal pharyngitis develops migratory polyarthritis, a new cardiac murmur, and subcutaneous nodules. Which diagnostic criteria are used to confirm this condition?
    • The Wells criteria
    • The Jones criteria
    • The Duke criteria
    • The Centor criteria

    Correct answer: The Jones criteria

    The Jones criteria are correct because they diagnose acute rheumatic fever using major features such as carditis, migratory polyarthritis, and subcutaneous nodules following streptococcal infection. The Wells criteria estimate thrombosis probability, the Duke criteria diagnose infective endocarditis, and the Centor criteria estimate the likelihood of streptococcal pharyngitis rather than its rheumatic sequelae.

47. A 60-year-old woman presents with acute chest pain, ST-segment elevation, and apical ballooning of the left ventricle on imaging shortly after the sudden death of her spouse, but coronary angiography shows no obstruction. Which diagnosis best fits?
    • ST-elevation myocardial infarction from plaque rupture
    • Chronic stable angina
    • Takotsubo (stress) cardiomyopathy
    • Aortic stenosis

    Correct answer: Takotsubo (stress) cardiomyopathy

    Takotsubo (stress) cardiomyopathy is correct because acute chest pain with ST elevation and apical ballooning after intense emotional stress, with normal coronary arteries, is characteristic of this catecholamine-mediated syndrome. Plaque-rupture myocardial infarction would reveal obstructive disease, while stable angina and aortic stenosis do not produce transient apical ballooning.

48. A 55-year-old man presents with sudden severe tearing chest pain radiating to the back and a 20 mmHg difference in systolic blood pressure between arms. Which diagnosis must be urgently excluded?
    • Gastroesophageal reflux disease
    • Costochondritis
    • Stable angina
    • Acute aortic dissection

    Correct answer: Acute aortic dissection

    Acute aortic dissection is correct because abrupt tearing chest pain radiating to the back with an interarm blood pressure differential strongly suggests a dissecting aorta, a life-threatening emergency. Reflux, costochondritis, and stable angina do not cause a tearing quality with pulse and pressure asymmetry between the arms.

49. Which medication class is used to acutely control heart rate and blood pressure and reduce aortic wall shear stress in a patient with acute aortic dissection?
    • Intravenous beta-blockers
    • Intravenous positive inotropes
    • Oral calcium supplementation
    • Systemic thrombolytics

    Correct answer: Intravenous beta-blockers

    Intravenous beta-blockers are correct because lowering heart rate and contractility reduces aortic wall shear stress and limits propagation of an aortic dissection. Positive inotropes increase shear stress, calcium supplementation has no role, and thrombolytics are dangerous because they can worsen bleeding into the dissection.

50. A 68-year-old woman with chronic heart failure presents with worsening dyspnea, weight gain, and an elevated B-type natriuretic peptide. Which initial treatment addresses her volume overload?
    • An intravenous fluid bolus
    • An intravenous loop diuretic
    • Oral iron supplementation
    • A nondihydropyridine calcium channel blocker

    Correct answer: An intravenous loop diuretic

    An intravenous loop diuretic is correct because decompensated heart failure with congestion and elevated natriuretic peptide is treated by removing excess fluid through diuresis. A fluid bolus would worsen congestion, iron supplementation does not relieve acute volume overload, and nondihydropyridine calcium channel blockers can depress contractility and are avoided in reduced ejection fraction heart failure.

51. A patient with reduced ejection fraction heart failure is already taking an angiotensin receptor-neprilysin inhibitor and a beta-blocker. Adding which agent further reduces mortality by blocking aldosterone?
    • Amlodipine
    • Hydrochlorothiazide
    • Spironolactone
    • Verapamil

    Correct answer: Spironolactone

    Spironolactone is correct because the mineralocorticoid receptor antagonist blocks aldosterone and provides additional mortality benefit in reduced ejection fraction heart failure when added to other guideline-directed agents. Amlodipine and hydrochlorothiazide do not reduce heart failure mortality, and verapamil depresses contractility and is contraindicated in this setting.

52. A patient with a history of myocardial infarction presents to the emergency department with chest pain. Which biomarker is most specific and sensitive for confirming acute myocardial injury?
    • C-reactive protein
    • Serum lactate dehydrogenase
    • Aspartate aminotransferase
    • Cardiac troponin

    Correct answer: Cardiac troponin

    Cardiac troponin is correct because it is the most specific and sensitive biomarker for myocardial injury and is central to diagnosing acute myocardial infarction. C-reactive protein is a nonspecific inflammatory marker, and lactate dehydrogenase and aspartate aminotransferase rise in many tissues and lack the cardiac specificity of troponin.

53. Following a non-ST-elevation myocardial infarction managed with a coronary stent, which combination is recommended to reduce stent thrombosis?
    • Dual antiplatelet therapy with aspirin and a P2Y12 inhibitor
    • Warfarin monotherapy
    • Aspirin alone indefinitely
    • A loop diuretic plus a statin

    Correct answer: Dual antiplatelet therapy with aspirin and a P2Y12 inhibitor

    Dual antiplatelet therapy with aspirin and a P2Y12 inhibitor is correct because the combination prevents stent thrombosis after percutaneous coronary intervention for acute coronary syndrome. Warfarin and aspirin alone do not provide adequate platelet inhibition after stenting, and a diuretic plus statin addresses volume and lipids rather than platelet-mediated stent occlusion.

54. A patient with atrial fibrillation is being assessed for bleeding risk before starting anticoagulation. Which scoring system is designed to estimate that bleeding risk?
    • The CHA2DS2-VASc score
    • The HAS-BLED score
    • The Wells score
    • The CURB-65 score

    Correct answer: The HAS-BLED score

    The HAS-BLED score is correct because it estimates major bleeding risk on anticoagulation in atrial fibrillation, complementing the stroke risk assessment. The CHA2DS2-VASc score estimates stroke risk, the Wells score estimates thrombosis probability, and CURB-65 grades pneumonia severity, none of which quantify anticoagulant bleeding risk.

55. A patient with longstanding hypertension is found to have left ventricular hypertrophy on electrocardiogram. Which long-term complication is this finding most associated with?
    • Resolution of hypertension without treatment
    • A reduced risk of arrhythmia
    • Heart failure and increased cardiovascular events
    • Improved diastolic relaxation

    Correct answer: Heart failure and increased cardiovascular events

    Heart failure and increased cardiovascular events is correct because hypertension-induced left ventricular hypertrophy reflects pressure overload and independently predicts heart failure, arrhythmia, and adverse cardiovascular outcomes. It does not signal spontaneous resolution of hypertension, it increases rather than reduces arrhythmia risk, and it impairs rather than improves diastolic relaxation.

56. A 62-year-old with stable angina and an ejection fraction within normal limits remains symptomatic despite sublingual nitroglycerin as needed. Which medication is appropriate first-line chronic therapy to reduce anginal episodes?
    • A short-acting nitrate taken only as needed
    • An oral anticoagulant
    • A proton pump inhibitor
    • A beta-blocker

    Correct answer: A beta-blocker

    A beta-blocker is correct because reducing heart rate and contractility lowers myocardial oxygen demand and is first-line chronic anti-anginal therapy in stable coronary disease. As-needed nitrates alone do not provide ongoing prophylaxis, anticoagulation is not indicated for stable angina, and a proton pump inhibitor treats acid-related disease rather than ischemia.

57. A patient with reduced ejection fraction heart failure has a resting heart rate of 78 beats per minute in sinus rhythm despite maximally tolerated beta-blockade and remains symptomatic. Which agent specifically lowers heart rate by inhibiting the sinoatrial node funny current?
    • Ivabradine
    • Digoxin
    • Amiodarone
    • Lisinopril

    Correct answer: Ivabradine

    Ivabradine is correct because it selectively inhibits the funny current in the sinoatrial node to slow heart rate and reduce heart failure hospitalizations in symptomatic sinus-rhythm patients with elevated heart rate despite beta-blockade. Digoxin and amiodarone act through different mechanisms, and lisinopril lowers afterload rather than directly slowing the sinus node.

58. A 58-year-old man with a CHA2DS2-VASc score indicating high stroke risk has nonvalvular atrial fibrillation and normal renal function. Which agent is preferred over warfarin for stroke prevention in most such patients?
    • Low-dose aspirin
    • A direct oral anticoagulant such as apixaban
    • Subcutaneous enoxaparin indefinitely
    • Dual antiplatelet therapy with aspirin and clopidogrel

    Correct answer: A direct oral anticoagulant such as apixaban

    A direct oral anticoagulant such as apixaban is correct because direct oral anticoagulants are preferred over warfarin in most patients with nonvalvular atrial fibrillation and normal renal function due to comparable or better efficacy with less monitoring and lower intracranial bleeding. Aspirin and dual antiplatelet therapy are inadequate for stroke prevention in high-risk atrial fibrillation, and indefinite enoxaparin is impractical and not first-line.

59. A 64-year-old man with benign prostatic hyperplasia reports that his obstructive voiding symptoms have improved on tamsulosin, but he now feels dizzy when he stands up quickly, especially after the first dose. Which mechanism best explains this adverse effect?
    • Alpha-1 receptor blockade causing orthostatic hypotension
    • Beta-3 receptor stimulation reducing cardiac output
    • Anticholinergic blockade slowing the heart rate
    • 5-alpha-reductase inhibition lowering blood pressure

    Correct answer: Alpha-1 receptor blockade causing orthostatic hypotension

    Alpha-1 receptor blockade causing orthostatic hypotension is correct because alpha-blockers relax vascular smooth muscle in addition to prostatic smooth muscle, producing first-dose dizziness and postural drops in pressure. Beta-3 agonists like mirabegron act on the bladder, not as the cause here. Anticholinergic effects do not slow heart rate to produce orthostasis. 5-alpha-reductase inhibitors do not cause significant orthostatic hypotension.

60. A 69-year-old man with bothersome benign prostatic hyperplasia and concurrent erectile dysfunction asks whether one medication could address both problems. Which agent is approved to treat both lower urinary tract symptoms from BPH and erectile dysfunction?
    • Finasteride
    • Oxybutynin
    • Tadalafil
    • Doxazosin

    Correct answer: Tadalafil

    Tadalafil is correct because this long-acting phosphodiesterase-5 inhibitor is approved both for erectile dysfunction and for lower urinary tract symptoms attributable to benign prostatic hyperplasia, making it a single option for men with both conditions. Finasteride shrinks the prostate but does not treat erectile dysfunction and may worsen it. Oxybutynin treats overactive bladder. Doxazosin relieves BPH symptoms but does not treat erectile dysfunction.

61. A 66-year-old man with severe benign prostatic hyperplasia has failed combination medical therapy and now has recurrent gross hematuria and a second episode of acute urinary retention. Which intervention is the most appropriate definitive treatment for refractory obstructive symptoms?
    • Transurethral resection of the prostate
    • Lifelong indwelling urethral catheter
    • Addition of an anticholinergic agent
    • Bilateral orchiectomy

    Correct answer: Transurethral resection of the prostate

    Transurethral resection of the prostate is correct because surgical resection is the standard definitive treatment when medical therapy fails and complications such as recurrent retention or refractory hematuria develop. A permanent catheter is a last resort for poor surgical candidates, not a preferred definitive treatment. Anticholinergics can worsen retention in obstructed patients. Orchiectomy treats androgen-dependent prostate cancer, not benign obstruction.

62. A 50-year-old man passes a kidney stone and 24-hour urine studies show low urinary citrate. Which medication is most appropriate to reduce his risk of recurrent calcium stones by raising urinary citrate?
    • Hydrochlorothiazide
    • Allopurinol
    • Acetazolamide
    • Potassium citrate

    Correct answer: Potassium citrate

    Potassium citrate is correct because citrate binds urinary calcium and inhibits crystal formation, so supplementation directly corrects hypocitraturia and reduces calcium stone recurrence. Hydrochlorothiazide lowers urinary calcium excretion and is used for hypercalciuria, a different defect. Allopurinol targets uric acid overproduction. Acetazolamide alkalinizes urine but can promote calcium phosphate stones and is not used for this purpose.

63. A 45-year-old woman with recurrent calcium stones has 24-hour urine testing showing hypercalciuria with normal serum calcium. Which medication reduces urinary calcium excretion and is most appropriate to prevent recurrence?
    • Furosemide
    • Potassium citrate
    • A thiazide diuretic
    • Sodium bicarbonate

    Correct answer: A thiazide diuretic

    A thiazide diuretic is correct because thiazides increase renal tubular reabsorption of calcium, lowering urinary calcium and reducing calcium stone formation in hypercalciuric patients. Furosemide is a loop diuretic that increases urinary calcium and worsens the problem. Potassium citrate corrects low citrate, not high calcium excretion. Sodium bicarbonate alkalinizes urine and the sodium load can actually increase calcium excretion.

64. A 38-year-old man presents with acute right flank pain and gross hematuria. Imaging confirms a single 7 mm stone in the proximal ureter causing mild hydronephrosis, and he is afebrile with adequate pain control. After a trial of medical expulsive therapy fails over several weeks, which procedure is most appropriate for a stone of this size and location?
    • Open ureterolithotomy
    • Percutaneous nephrostomy alone
    • Continued observation for another three months
    • Ureteroscopy with laser lithotripsy or shock wave lithotripsy

    Correct answer: Ureteroscopy with laser lithotripsy or shock wave lithotripsy

    Ureteroscopy with laser lithotripsy or shock wave lithotripsy is correct because stones larger than about 5 to 6 mm that fail to pass are best treated with active stone removal by these minimally invasive techniques. Open surgery is reserved for complex cases that cannot be managed endoscopically. Nephrostomy alone drains the kidney but does not remove the stone. Indefinite observation risks ongoing obstruction and renal injury.

65. A patient with recurrent kidney stones forms calculi in persistently alkaline urine, and analysis reveals magnesium ammonium phosphate composition. Imaging shows a large branching stone filling the renal pelvis. Which underlying condition most likely explains these struvite stones?
    • Chronic infection with urease-producing bacteria
    • Hyperuricemia from gout
    • Inherited defect in cystine transport
    • Primary hyperparathyroidism

    Correct answer: Chronic infection with urease-producing bacteria

    Chronic infection with urease-producing bacteria is correct because organisms such as Proteus split urea to ammonia, raising urine pH and precipitating magnesium ammonium phosphate, which forms large staghorn struvite calculi. Hyperuricemia produces uric acid stones in acidic urine. A cystine transport defect produces cystine stones. Primary hyperparathyroidism causes calcium stones from hypercalciuria, not struvite stones.

66. A 16-year-old boy presents 3 hours after sudden severe left scrotal pain. The affected testis is high-riding and the cremasteric reflex is absent. A skilled provider is briefly delayed in performing surgery. Which bedside maneuver may temporarily restore blood flow while preparing for definitive treatment of testicular torsion?
    • Application of firm continuous pressure to the testis
    • Manual detorsion by rotating the testis outward, like opening a book
    • Vigorous massage of the spermatic cord
    • Ice packs applied directly to bare scrotal skin

    Correct answer: Manual detorsion by rotating the testis outward, like opening a book

    Manual detorsion by rotating the testis outward in an open-book fashion is correct because the testis usually twists inward, so outward rotation can untwist the cord and temporarily restore perfusion while surgery is arranged. Firm continuous pressure does not relieve the twist. Vigorous cord massage can worsen injury. Direct ice on bare skin risks frostbite and does not address the underlying torsion, which still requires surgical fixation.

67. An 8-day-old male newborn is noted to have a firm, painless, enlarged, and discolored hemiscrotum with a smooth, nontender testis on the affected side. The scrotal skin is dusky. Which statement about neonatal testicular torsion is most accurate?
    • It is always painful and the infant will be highly irritable
    • It is typically extravaginal and the affected testis is usually already nonviable at birth
    • It is reliably reversible with manual detorsion in the nursery
    • It is an indication for immediate bilateral orchiectomy

    Correct answer: It is typically extravaginal and the affected testis is usually already nonviable at birth

    It is typically extravaginal and the affected testis is usually already nonviable at birth is correct because neonatal torsion occurs outside the tunica vaginalis and most often happens prenatally, so the testis is frequently already infarcted by the time of presentation. It is usually painless rather than reliably painful. Manual detorsion does not salvage an already infarcted testis. Management addresses the affected side surgically and protects the contralateral testis, not bilateral removal.

68. A 33-year-old sexually active man has acute bacterial prostatitis confirmed clinically. He is hospitalized for high fever and rigors, and develops worsening pelvic pain with a fluctuant area on rectal exam despite appropriate intravenous antibiotics. Which complication should be suspected, and how is it confirmed?
    • Bladder cancer confirmed by cytology
    • Testicular torsion confirmed by Doppler ultrasound
    • Chronic pelvic pain syndrome confirmed by urine culture
    • Prostatic abscess confirmed by transrectal ultrasound or CT imaging

    Correct answer: Prostatic abscess confirmed by transrectal ultrasound or CT imaging

    Prostatic abscess confirmed by transrectal ultrasound or CT imaging is correct because failure to improve on antibiotics with a fluctuant prostate suggests abscess formation, which is diagnosed by imaging and may require drainage. Bladder cancer would not present this way in a young febrile man. Testicular torsion causes acute scrotal pain, not a fluctuant prostate. Chronic pelvic pain syndrome is afebrile with negative cultures and no abscess.

69. A 45-year-old man has recurrent urinary tract infections caused by the same organism over several months, with symptoms that recur after each antibiotic course ends. Between episodes he is relatively asymptomatic, and expressed prostatic secretions grow bacteria. Which diagnosis best explains the recurrent same-organism infections?
    • Acute bacterial prostatitis
    • Chronic bacterial prostatitis
    • Benign prostatic hyperplasia
    • Asymptomatic inflammatory prostatitis

    Correct answer: Chronic bacterial prostatitis

    Chronic bacterial prostatitis is correct because the prostate serves as a persistent reservoir, producing recurrent urinary infections with the same organism that returns after each antibiotic course, often requiring prolonged therapy. Acute bacterial prostatitis presents abruptly with fever and severe symptoms, not a relapsing pattern. Benign prostatic hyperplasia causes obstructive symptoms without recurrent same-organism infection. Asymptomatic inflammatory prostatitis is found incidentally without recurrent infections.

70. A 24-year-old man develops gradual onset left scrotal pain and swelling over two days. Examination shows a tender, indurated epididymis with relief of pain on scrotal elevation, and color Doppler shows increased blood flow to the affected epididymis. Which finding most clearly distinguishes this condition from testicular torsion?
    • Increased rather than absent testicular blood flow on Doppler
    • A high-riding testis with a horizontal lie
    • Absent cremasteric reflex on the affected side
    • Sudden onset of pain reaching maximum within minutes

    Correct answer: Increased rather than absent testicular blood flow on Doppler

    Increased rather than absent testicular blood flow on Doppler is correct because epididymitis is an inflammatory process with hyperemia, whereas torsion shows decreased or absent flow from a twisted cord. A high-riding horizontal testis and an absent cremasteric reflex favor torsion. Sudden pain peaking within minutes is characteristic of torsion, while epididymitis develops more gradually.

71. A 55-year-old man presents with acute epididymitis. He has no urethral discharge, is not at high risk for sexually transmitted infections, and has a history of benign prostatic hyperplasia with incomplete bladder emptying. Which empiric antibiotic choice is most appropriate for the most likely pathogen in this older man?
    • Ceftriaxone plus doxycycline targeting gonorrhea and chlamydia
    • A fluoroquinolone such as levofloxacin targeting enteric gram-negative organisms
    • Topical antifungal therapy
    • Acyclovir for herpes simplex

    Correct answer: A fluoroquinolone such as levofloxacin targeting enteric gram-negative organisms

    A fluoroquinolone targeting enteric gram-negative organisms is correct because in older men with urinary obstruction and no STI risk, epididymitis is usually caused by coliform bacteria such as Escherichia coli, which respond to fluoroquinolone coverage. Ceftriaxone plus doxycycline targets sexually transmitted organisms typical of younger men. Antifungals and acyclovir do not treat bacterial epididymitis.

72. A 28-year-old man is diagnosed with a nonseminomatous germ cell tumor of the testis after radical inguinal orchiectomy. Which tumor marker is most useful for monitoring this patient for residual or recurrent disease during follow-up?
    • Prostate-specific antigen
    • CA-125
    • Carcinoembryonic antigen
    • Alpha-fetoprotein and beta-hCG

    Correct answer: Alpha-fetoprotein and beta-hCG

    Alpha-fetoprotein and beta-hCG is correct because these serum markers are produced by many nonseminomatous germ cell tumors and are used to monitor treatment response and detect recurrence. Prostate-specific antigen tracks prostate disease, not testicular tumors. CA-125 is associated with ovarian cancer. Carcinoembryonic antigen is used for colorectal and other adenocarcinomas, not testicular germ cell tumors.

73. A 30-year-old man presents with a painless, firm testicular mass and is found to have a pure seminoma confined to the testis after orchiectomy. Compared with nonseminomatous germ cell tumors, which characteristic is most typical of seminoma?
    • It rarely elevates alpha-fetoprotein and is highly radiosensitive
    • It always produces markedly elevated alpha-fetoprotein
    • It is resistant to both radiation and chemotherapy
    • It occurs almost exclusively in men over 70

    Correct answer: It rarely elevates alpha-fetoprotein and is highly radiosensitive

    It rarely elevates alpha-fetoprotein and is highly radiosensitive is correct because pure seminomas characteristically do not raise alpha-fetoprotein and respond well to radiation therapy, distinguishing them from nonseminomatous tumors. A markedly elevated alpha-fetoprotein actually suggests a nonseminomatous component. Seminomas are quite sensitive to treatment, not resistant. Germ cell tumors typically affect younger men, not those over 70.

74. A 70-year-old man with painless gross hematuria is evaluated and found to have a bladder mass. Biopsy confirms urothelial carcinoma. Which exposure is the strongest established risk factor for this malignancy?
    • High dietary calcium intake
    • Chronic NSAID use
    • Cigarette smoking
    • Excessive caffeine consumption

    Correct answer: Cigarette smoking

    Cigarette smoking is correct because tobacco is the single strongest and most common modifiable risk factor for urothelial bladder cancer, with carcinogens excreted in the urine contacting the bladder lining. High dietary calcium relates to kidney stones, not bladder cancer. Chronic NSAID use is not an established bladder cancer risk factor. Caffeine has not been shown to meaningfully increase bladder cancer risk.

75. A 62-year-old woman presents with chronic continuous dribbling of urine and a sensation that her bladder never fully empties. Postvoid residual volume is markedly elevated at 400 mL, and she has diabetic peripheral neuropathy. Which type of urinary incontinence does this presentation best represent?
    • Stress incontinence
    • Urge incontinence
    • Overflow incontinence
    • Functional incontinence

    Correct answer: Overflow incontinence

    Overflow incontinence is correct because continuous dribbling with a markedly elevated postvoid residual reflects a chronically overdistended, poorly contractile bladder, which can result from diabetic neuropathy impairing detrusor function. Stress incontinence is leakage with exertion and normal emptying. Urge incontinence features sudden urgency without retention. Functional incontinence arises from mobility or cognitive barriers, not an overdistended bladder.

76. A 78-year-old man with advanced dementia and limited mobility frequently has incontinent episodes because he cannot reach or recognize the need to use the toilet in time, although his bladder and sphincter function are intact. Which intervention is most appropriate for this functional incontinence?
    • Antimuscarinic medication
    • Scheduled toileting and environmental modifications such as a bedside commode
    • Surgical sling placement
    • Intermittent catheterization

    Correct answer: Scheduled toileting and environmental modifications such as a bedside commode

    Scheduled toileting and environmental modifications such as a bedside commode is correct because functional incontinence results from cognitive and mobility limitations rather than urinary tract dysfunction, so behavioral and access-focused measures are first-line. Antimuscarinics treat detrusor overactivity and risk worsening cognition in dementia. A sling addresses stress incontinence. Catheterization is for retention and adds infection risk without addressing the access problem.

77. A 25-year-old man is found to have a left varicocele. The provider explains that surgical or radiologic treatment may be considered in specific situations. Which scenario most strongly supports intervention rather than observation?
    • An asymptomatic small varicocele in a man not pursuing fertility
    • A varicocele that decreases in size when the patient lies supine
    • A varicocele present since adolescence without symptoms or fertility concerns
    • A varicocele associated with impaired semen parameters in a couple with infertility

    Correct answer: A varicocele associated with impaired semen parameters in a couple with infertility

    A varicocele associated with impaired semen parameters in a couple with infertility is correct because correcting a clinically significant varicocele in this setting can improve sperm parameters and fertility outcomes. An asymptomatic small varicocele in a man not pursuing fertility usually warrants observation. Decreasing in size when supine is a normal expected feature, not an indication for surgery. A long-standing asymptomatic varicocele without fertility concerns does not require intervention.

78. A 16-year-old boy is incidentally found to have a new, isolated right-sided varicocele that does not decrease when he lies down. Why does this specific finding warrant additional imaging of the abdomen?
    • Right-sided varicoceles are always congenital and benign
    • An isolated right varicocele that fails to decompress supine can indicate a retroperitoneal mass obstructing venous drainage
    • Right-sided varicoceles indicate testicular torsion
    • The finding confirms benign prostatic hyperplasia

    Correct answer: An isolated right varicocele that fails to decompress supine can indicate a retroperitoneal mass obstructing venous drainage

    An isolated right varicocele that fails to decompress supine can indicate a retroperitoneal mass obstructing venous drainage is correct because varicoceles are usually left-sided, so a new right-sided one that does not collapse when supine raises concern for a mass compressing the venous return and warrants abdominal imaging. Right varicoceles are not always benign in this scenario. They do not indicate torsion. Benign prostatic hyperplasia is unrelated to a teenage varicocele.

79. A 35-year-old man presents with a soft scrotal swelling that increases in size during the day and after standing. It is located above and posterior to the testis, transilluminates, and feels separate from the testis on palpation. Which diagnosis best fits this scrotal finding?
    • Spermatocele (epididymal cyst)
    • Inguinal hernia
    • Testicular tumor
    • Acute orchitis

    Correct answer: Spermatocele (epididymal cyst)

    Spermatocele (epididymal cyst) is correct because a painless, transilluminating cystic mass located above and behind the testis and clearly separate from it is characteristic of a fluid-filled epididymal cyst. An inguinal hernia may extend into the scrotum but typically does not transilluminate and may reduce. A testicular tumor is firm, intratesticular, and does not transilluminate. Acute orchitis is painful with a tender swollen testis.

80. A 22-year-old man develops painful unilateral testicular swelling about five days after the onset of bilateral parotid gland swelling and fever. Examination shows a tender, enlarged testis with normal Doppler blood flow. Which cause of orchitis is most consistent with this presentation?
    • Mumps virus
    • Escherichia coli ascending infection
    • Testicular torsion
    • Tuberculous infection

    Correct answer: Mumps virus

    Mumps virus is correct because mumps orchitis classically follows parotitis by several days in a postpubertal male, causing painful testicular swelling, and the diagnosis is supported by the preceding bilateral parotid swelling. An ascending Escherichia coli infection would be associated with urinary symptoms, not parotitis. Torsion shows absent blood flow and abrupt onset without parotitis. Tuberculous involvement is chronic and indolent, not acute post-parotitis.

81. A 4-year-old uncircumcised boy is brought in with a swollen, painful, erythematous foreskin and tip of the penis, with purulent discharge under the foreskin. The foreskin cannot be retracted. Which condition does this represent?
    • Paraphimosis
    • Balanitis
    • Priapism
    • Hypospadias

    Correct answer: Balanitis

    Balanitis is correct because inflammation and infection of the glans and foreskin with erythema, swelling, and discharge in an uncircumcised boy defines balanitis (balanoposthitis when the foreskin is involved). Paraphimosis is a trapped retracted foreskin causing a constricting band, not infection of the unretracted foreskin. Priapism is a prolonged erection. Hypospadias is a congenital misplaced meatus, not an acute inflammatory infection.

82. A 19-year-old uncircumcised man presents with a painful, swollen glans after the foreskin was retracted during catheter placement and not returned to its normal position. The retracted foreskin now forms a tight constricting band proximal to the glans, which is edematous. What is the most appropriate immediate management of this paraphimosis?
    • Reassurance and outpatient urology referral in two weeks
    • Immediate circumcision in the clinic without reduction attempt
    • Application of a constricting tourniquet to the penile shaft
    • Manual compression of the glans to reduce edema and reduce the foreskin back over the glans

    Correct answer: Manual compression of the glans to reduce edema and reduce the foreskin back over the glans

    Manual compression of the glans to reduce edema and reduce the foreskin is correct because paraphimosis is a urologic emergency in which the trapped foreskin compromises glans circulation, so gentle steady compression to decrease swelling followed by reduction relieves the constriction. Delayed referral risks ischemic injury. Emergency dorsal slit may be needed only if reduction fails, not routine immediate circumcision. A shaft tourniquet would worsen ischemia.

83. A 63-year-old man with newly diagnosed benign prostatic hyperplasia is evaluated before starting treatment. Which finding in his history or workup is a red flag that warrants further evaluation or specialist referral rather than simple initiation of medical therapy?
    • Mild nocturia once per night
    • An International Prostate Symptom Score in the mild range
    • A smooth, symmetrically enlarged prostate on rectal exam
    • Gross hematuria, recurrent urinary tract infections, or an abnormal prostate nodule

    Correct answer: Gross hematuria, recurrent urinary tract infections, or an abnormal prostate nodule

    Gross hematuria, recurrent urinary tract infections, or an abnormal prostate nodule is correct because these features raise concern for malignancy, obstruction with complications, or other pathology beyond uncomplicated benign prostatic hyperplasia and warrant further workup or referral. Mild nocturia and a mild symptom score reflect uncomplicated disease suitable for routine management. A smooth, symmetrically enlarged prostate is the expected benign finding, not a red flag.

84. A 58-year-old man with poorly controlled hypertension presents 90 minutes after the abrupt onset of right-arm weakness and slurred speech. His blood pressure is 168/92 mmHg, blood glucose is normal, and a noncontrast head CT shows no hemorrhage. Which factor would most strongly exclude him from receiving intravenous thrombolytic therapy?
    • A blood pressure of 168/92 mmHg
    • An age of 58 years
    • A documented major surgery 1 week ago
    • A history of well-controlled hypertension

    Correct answer: A documented major surgery 1 week ago

    A documented major surgery 1 week ago is the answer because recent major surgery within the prior 14 days is a contraindication to intravenous thrombolysis due to the high risk of serious bleeding. A blood pressure of 168/92 mmHg is below the 185/110 threshold and can be treated, an age of 58 is acceptable, and well-controlled chronic hypertension alone does not preclude therapy.

85. A 67-year-old woman is brought in with sudden left-sided weakness that began exactly 2 hours ago. She is eligible for intravenous alteplase. What is the maximum time window from symptom onset within which intravenous thrombolysis is generally recommended for acute ischemic stroke?
    • Up to 24 hours from onset
    • Up to 4.5 hours from onset
    • Up to 12 hours from onset
    • Up to 8 hours from onset

    Correct answer: Up to 4.5 hours from onset

    Up to 4.5 hours from onset is the answer because intravenous thrombolysis for acute ischemic stroke is recommended within 4.5 hours of symptom onset in eligible patients. The 24-hour figure applies to selected mechanical thrombectomy candidates rather than thrombolysis, and the 8- and 12-hour options exceed the established thrombolytic window.

86. A 74-year-old man develops transient right-hand clumsiness and difficulty speaking that completely resolves within 30 minutes, leaving a normal neurologic exam and a normal head CT. Which description best characterizes this event?
    • A transient ischemic attack with full neurologic recovery
    • A completed ischemic stroke with permanent deficit
    • A primary intracerebral hemorrhage
    • A focal seizure with postictal weakness

    Correct answer: A transient ischemic attack with full neurologic recovery

    A transient ischemic attack with full neurologic recovery is the answer because a focal neurologic deficit from ischemia that resolves completely without infarction on imaging defines a transient ischemic attack. A completed stroke leaves a persistent deficit, intracerebral hemorrhage shows blood on CT, and a focal seizure produces positive symptoms or postictal weakness rather than this transient ischemic pattern.

87. A 26-year-old man is witnessed to have a generalized tonic-clonic seizure that has continued for more than 5 continuous minutes without stopping. Which medication class should be administered first to abort the seizure?
    • An oral sodium-channel blocker
    • An intravenous beta-blocker
    • A subcutaneous triptan
    • An intravenous or intramuscular benzodiazepine

    Correct answer: An intravenous or intramuscular benzodiazepine

    An intravenous or intramuscular benzodiazepine is the answer because a benzodiazepine such as lorazepam or midazolam is the first-line agent to terminate convulsive status epilepticus. An oral antiseizure agent is too slow to act, a beta-blocker has no antiseizure effect, and a triptan treats migraine rather than seizures.

88. A 30-year-old woman with epilepsy presents after a prolonged convulsive seizure. By definition, status epilepticus is most appropriately recognized when a single generalized convulsive seizure lasts at least how long, prompting emergency treatment?
    • 30 seconds
    • 5 minutes
    • 20 minutes
    • 60 minutes

    Correct answer: 5 minutes

    5 minutes is the answer because current operational definitions treat a generalized convulsive seizure lasting 5 minutes or longer, or repeated seizures without recovery in between, as status epilepticus requiring immediate treatment. Thirty seconds is within a typical self-limited seizure, while waiting 20 or 60 minutes would dangerously delay therapy.

89. A 22-year-old man describes episodes in which he suddenly stops, stares, smacks his lips, and picks at his clothing for about a minute, then is confused afterward and does not recall the event. Which seizure type best fits this description?
    • Generalized absence seizure
    • Generalized tonic-clonic seizure
    • Focal seizure with impaired awareness
    • Myoclonic seizure

    Correct answer: Focal seizure with impaired awareness

    Focal seizure with impaired awareness is the answer because behavioral arrest with automatisms such as lip-smacking and picking, lasting around a minute with postictal confusion and amnesia, is characteristic of a focal seizure with impaired awareness, often of temporal lobe origin. Absence seizures are brief without postictal confusion, tonic-clonic seizures involve bilateral convulsions, and myoclonic seizures are brief shock-like jerks.

90. A 28-year-old woman with frequent disabling migraines occurring 8 days per month asks about reducing how often they happen. Which medication is an appropriate first-line option for migraine prophylaxis?
    • Oral sumatriptan taken daily
    • Topiramate taken daily
    • Acetaminophen taken at headache onset
    • Inhaled high-flow oxygen during attacks

    Correct answer: Topiramate taken daily

    Topiramate taken daily is the answer because it is an established first-line preventive medication that reduces migraine frequency when taken regularly. Daily triptans risk medication-overuse headache and are abortive rather than preventive, acetaminophen at onset is an acute treatment, and high-flow oxygen is used for cluster headache attacks rather than migraine prevention.

91. A 45-year-old man presents with the worst headache of his life that reached maximal intensity within seconds, described as a thunderclap. Which condition must be excluded most urgently?
    • Tension-type headache
    • Chronic migraine
    • Cervicogenic headache
    • Subarachnoid hemorrhage

    Correct answer: Subarachnoid hemorrhage

    Subarachnoid hemorrhage is the answer because a sudden severe thunderclap headache peaking within seconds is the classic red-flag presentation of aneurysmal subarachnoid hemorrhage, evaluated with noncontrast CT and lumbar puncture if needed. Tension-type headache, chronic migraine, and cervicogenic headache develop more gradually and do not produce this abrupt maximal-onset pattern.

92. A 34-year-old woman with episodic migraine without aura is in the emergency department with an acute, moderately severe migraine that has not responded to acetaminophen at home. Which medication class is the most appropriate migraine-specific abortive therapy?
    • A triptan such as sumatriptan
    • A long-acting oral opioid
    • A daily oral beta-blocker
    • An oral proton pump inhibitor

    Correct answer: A triptan such as sumatriptan

    A triptan such as sumatriptan is the answer because triptans are migraine-specific abortive agents that constrict cranial vessels and inhibit neuropeptide release to relieve an acute attack. Opioids are discouraged due to dependence and rebound risk, a beta-blocker is a preventive rather than an abortive agent, and a proton pump inhibitor has no role in migraine.

93. A 70-year-old man with Parkinson disease is noted on exam to have a slow, shuffling gait, reduced arm swing, a pill-rolling resting tremor, and cogwheel rigidity. Which underlying neuropathologic change accounts for these motor features?
    • Degeneration of dopaminergic neurons in the substantia nigra
    • Demyelination of central white-matter tracts
    • Autoimmune destruction of acetylcholine receptors
    • Occlusion of a small penetrating cerebral artery

    Correct answer: Degeneration of dopaminergic neurons in the substantia nigra

    Degeneration of dopaminergic neurons in the substantia nigra is the answer because loss of these nigrostriatal dopaminergic neurons produces the bradykinesia, resting tremor, and rigidity of Parkinson disease. Central demyelination underlies multiple sclerosis, acetylcholine receptor destruction underlies myasthenia gravis, and small-vessel occlusion causes lacunar stroke.

94. A 65-year-old woman with moderate Parkinson disease has worsening bradykinesia and rigidity that limit her daily function. Which medication provides the most effective symptomatic relief of her motor symptoms?
    • Carbidopa-levodopa
    • Donepezil
    • Propranolol
    • Phenytoin

    Correct answer: Carbidopa-levodopa

    Carbidopa-levodopa is the answer because levodopa, combined with carbidopa to limit peripheral conversion, is the most effective treatment for the motor symptoms of Parkinson disease. Donepezil treats Alzheimer-type dementia, propranolol is used for essential tremor, and phenytoin is an antiseizure drug, none of which address parkinsonian bradykinesia and rigidity.

95. A 36-year-old woman with relapsing-remitting multiple sclerosis presents with a 4-day history of worsening right leg weakness and new gait instability consistent with an acute relapse. Which treatment is most appropriate to shorten the duration of this acute exacerbation?
    • Oral gabapentin
    • A short course of high-dose corticosteroids
    • Subcutaneous insulin
    • Lifelong oral anticoagulation

    Correct answer: A short course of high-dose corticosteroids

    A short course of high-dose corticosteroids is the answer because high-dose corticosteroids speed recovery from an acute multiple sclerosis relapse by reducing central nervous system inflammation. Gabapentin treats neuropathic symptoms rather than the relapse, insulin manages diabetes, and anticoagulation addresses thrombotic disease, none of which shorten an acute demyelinating attack.

96. A 29-year-old woman is being evaluated for suspected multiple sclerosis after two distinct neurologic episodes affecting different regions over the past year. Which diagnostic principle is central to confirming the diagnosis?
    • A single peripheral nerve lesion confirmed by nerve conduction studies
    • Elevated serum creatine kinase on repeated testing
    • Lesions disseminated in space and in time within the central nervous system
    • A positive Dix-Hallpike maneuver

    Correct answer: Lesions disseminated in space and in time within the central nervous system

    Lesions disseminated in space and in time within the central nervous system is the answer because the diagnosis of multiple sclerosis requires demonstrating central nervous system lesions affecting different locations and occurring at different times, supported by MRI and clinical history. A single peripheral nerve lesion, elevated creatine kinase, and a positive Dix-Hallpike maneuver point to peripheral nerve, muscle, and vestibular disorders respectively.

97. A 52-year-old man presents with acute, complete left-sided peripheral facial weakness, including inability to close the left eye and flattening of the left nasolabial fold, with no other neurologic deficits and no rash. Which additional measure protects the eye on the affected side?
    • Lubricating eye drops and eye protection
    • Immediate intravenous thrombolysis
    • Urgent carotid endarterectomy
    • Long-term daily antiseizure medication

    Correct answer: Lubricating eye drops and eye protection

    Lubricating eye drops and eye protection is the answer because incomplete eyelid closure in Bell palsy leaves the cornea exposed and prone to drying and abrasion, so artificial tears and eye protection are essential supportive care. Thrombolysis and carotid endarterectomy treat ischemic vascular disease, and antiseizure medication has no role in this facial nerve palsy.

98. A 48-year-old woman is diagnosed with Bell palsy. When counseling her about prognosis, which statement is most accurate regarding the typical natural course of this condition?
    • Permanent complete paralysis is the expected outcome in most cases
    • Symptoms invariably progress to involve the opposite side of the face
    • Recovery requires lifelong immunosuppressive therapy
    • Most patients recover facial function over weeks to months

    Correct answer: Most patients recover facial function over weeks to months

    Most patients recover facial function over weeks to months is the answer because Bell palsy is usually self-limited, with the majority of patients regaining facial function over the following weeks to months, especially with early corticosteroids. Permanent complete paralysis, mandatory progression to the other side, and a need for lifelong immunosuppression do not reflect its typical favorable course.

99. A 60-year-old man develops sudden vertigo, ipsilateral facial numbness, loss of pain and temperature sensation on the opposite side of the body, hoarseness, and Horner syndrome. This lateral medullary presentation localizes to a stroke in the territory of which artery?
    • Anterior cerebral artery
    • Ophthalmic artery
    • Anterior spinal artery
    • Posterior inferior cerebellar artery

    Correct answer: Posterior inferior cerebellar artery

    Posterior inferior cerebellar artery is the answer because lateral medullary (Wallenberg) syndrome, with crossed sensory findings, vertigo, hoarseness, and Horner syndrome, results from occlusion of the posterior inferior cerebellar artery or the vertebral artery. The anterior cerebral artery causes contralateral leg weakness, the ophthalmic artery affects vision, and the anterior spinal artery produces an anterior cord syndrome.

100. A 19-year-old man develops ascending symmetric weakness beginning in the legs over several days, with loss of deep tendon reflexes, following a recent diarrheal illness. Cerebrospinal fluid shows elevated protein with a normal cell count. Which diagnosis best fits this presentation?
     • Parkinson disease
     • Bell palsy
     • Migraine with aura
     • Guillain-Barre syndrome

     Correct answer: Guillain-Barre syndrome

     Guillain-Barre syndrome is the answer because progressive ascending symmetric weakness with areflexia after a preceding infection, accompanied by elevated cerebrospinal fluid protein with few cells (albuminocytologic dissociation), is characteristic of this acute inflammatory demyelinating polyneuropathy. Parkinson disease, Bell palsy, and migraine with aura do not cause ascending areflexic weakness with this fluid finding.

101. A 25-year-old woman reports double vision and droopy eyelids that worsen as the day progresses and improve after rest, along with fatigable chewing. Antibodies against the acetylcholine receptor are detected. Which diagnosis is most consistent with these findings?
     • Multiple sclerosis
     • Huntington disease
     • Essential tremor
     • Myasthenia gravis

     Correct answer: Myasthenia gravis

     Myasthenia gravis is the answer because fatigable weakness that worsens with activity and improves with rest, particularly ptosis and diplopia, combined with acetylcholine receptor antibodies, defines this neuromuscular junction disorder. Multiple sclerosis causes central demyelination, Huntington disease causes chorea and dementia, and essential tremor produces an action tremor rather than fatigable weakness.

102. A 68-year-old woman with progressive memory loss has gradual decline in short-term memory and difficulty managing finances over 2 years, with otherwise normal motor exam and no early hallucinations or stepwise decline. Which diagnosis is most likely?
     • Vascular dementia
     • Normal-pressure hydrocephalus
     • Alzheimer disease
     • Creutzfeldt-Jakob disease

     Correct answer: Alzheimer disease

     Alzheimer disease is the answer because an insidious, gradually progressive decline dominated by short-term memory impairment and difficulty with complex tasks, without early focal motor signs or stepwise deterioration, is the typical pattern of Alzheimer disease. Vascular dementia tends to progress in steps with focal signs, normal-pressure hydrocephalus features gait disturbance and incontinence, and Creutzfeldt-Jakob disease progresses rapidly with myoclonus.

103. An 80-year-old man is brought in by family for an acute change in mental status that developed over 1 day, with fluctuating attention, disorientation, and visual hallucinations during a urinary tract infection. Which condition best explains this acute presentation?
     • Alzheimer disease
     • Delirium
     • Parkinson disease
     • Tension-type headache

     Correct answer: Delirium

     Delirium is the answer because an acute, fluctuating disturbance of attention and awareness with disorientation and perceptual changes, precipitated by an acute illness such as infection, defines delirium, which is typically reversible once the cause is treated. Alzheimer disease and Parkinson disease are chronic progressive disorders, and tension-type headache does not alter consciousness.

104. A 55-year-old man reports brief, severe, electric shock-like jolts of pain in the right cheek and jaw triggered by chewing, talking, or a light touch to the face, lasting only seconds at a time. Which medication is the most appropriate first-line treatment?
     • Acetaminophen
     • Prednisone
     • Carbamazepine
     • Sumatriptan

     Correct answer: Carbamazepine

     Carbamazepine is the answer because trigeminal neuralgia, characterized by brief paroxysms of severe facial pain in a trigeminal distribution provoked by light stimulation, responds best to carbamazepine as first-line therapy. Acetaminophen is inadequate for this neuropathic pain, corticosteroids are not indicated, and triptans treat migraine rather than trigeminal neuralgia.

105. A 72-year-old woman reports a rhythmic tremor of both hands that appears when she holds a cup or writes but disappears at rest, along with a family history of similar tremor and improvement after a small amount of alcohol. Which diagnosis best fits this presentation?
     • Parkinson disease
     • Cerebellar ataxia
     • Essential tremor
     • Huntington disease

     Correct answer: Essential tremor

     Essential tremor is the answer because a bilateral action (postural and kinetic) tremor that worsens with sustained posture and goal-directed movement, often familial and temporarily relieved by alcohol, is characteristic of essential tremor. Parkinson disease produces a resting tremor, cerebellar ataxia causes an intention tremor with incoordination, and Huntington disease causes chorea rather than a postural tremor.

106. A 40-year-old man presents with a deep, boring, strictly unilateral pain around the left eye occurring in clustered attacks lasting 30 to 90 minutes, with ipsilateral lacrimation and nasal congestion, several times daily over 2 weeks. Which medication is an appropriate option for preventing these attacks during the cluster period?
     • Verapamil
     • Daily oral opioids
     • Topical antibiotic eye drops
     • Oral ethosuximide

     Correct answer: Verapamil

     Verapamil is the answer because it is a first-line preventive medication used to reduce the frequency of cluster headache attacks during a cluster period. Daily opioids carry dependence and rebound risk and are not preventive, antibiotic eye drops treat infection, and ethosuximide is an antiseizure agent for absence epilepsy.

107. A 30-year-old man with chronic alcohol use disorder is admitted with confusion, gait ataxia, and abnormal eye movements including horizontal nystagmus and lateral gaze palsy. Which immediate treatment is most appropriate before giving glucose?
     • Oral aspirin
     • Intravenous thiamine
     • Intravenous magnesium only
     • High-flow oxygen

     Correct answer: Intravenous thiamine

     Intravenous thiamine is the answer because the triad of confusion, ataxia, and ophthalmoplegia in a patient with alcohol use disorder indicates Wernicke encephalopathy, which requires prompt thiamine before glucose to avoid worsening the deficiency. Aspirin, isolated magnesium, and oxygen do not correct the thiamine deficiency responsible for this emergency.

108. A 16-year-old girl has brief episodes of staring lasting about 10 seconds with no postictal confusion, occurring many times daily, sometimes provoked by hyperventilation, with an electroencephalogram showing 3-Hz generalized spike-and-wave discharges. Which seizure type does this represent?
     • Focal seizure with impaired awareness
     • Atonic seizure
     • Tonic-clonic seizure
     • Absence seizure

     Correct answer: Absence seizure

     Absence seizure is the answer because brief staring spells without postictal confusion, often provoked by hyperventilation and associated with a 3-Hz generalized spike-and-wave pattern, are characteristic of absence seizures. A focal seizure with impaired awareness involves automatisms and postictal confusion, an atonic seizure causes sudden loss of tone, and a tonic-clonic seizure produces sustained convulsions.

109. A 63-year-old woman presents with sudden severe vertigo, vomiting, truncal ataxia, and inability to sit unsupported after a hypertensive episode. Which feature most strongly suggests a central (cerebellar stroke) cause rather than a peripheral vestibular disorder?
     • Severe gait instability with inability to stand or walk
     • Symptoms reproduced only by repositioning the head
     • Unilateral ear fullness and hearing loss
     • Resolution within seconds of lying still

     Correct answer: Severe gait instability with inability to stand or walk

     Severe gait instability with inability to stand or walk is the answer because profound truncal ataxia preventing standing or walking points to a central cerebellar lesion such as a stroke rather than a peripheral cause, in which patients can usually still walk despite vertigo. Positional triggering, ear fullness with hearing loss, and rapid resolution with stillness favor a peripheral vestibular process.

110. A 45-year-old woman with a known seizure disorder has been seizure-free for 6 months on a single antiseizure medication and asks about safely continuing therapy. Which counseling point about adherence is most appropriate?
     • She may stop the medication now that she has been seizure-free for 6 months
     • She should take the medication consistently as prescribed, since abrupt discontinuation can provoke breakthrough seizures
     • She should double the dose on stressful days to prevent breakthrough seizures
     • She can skip doses whenever she feels well to reduce side effects

     Correct answer: She should take the medication consistently as prescribed, since abrupt discontinuation can provoke breakthrough seizures

     Taking the medication consistently as prescribed because abrupt discontinuation can provoke breakthrough seizures is the answer because steady adherence maintains therapeutic levels and sudden withdrawal is a well-recognized seizure trigger. Stopping after only 6 months without a clinician-guided plan, self-doubling doses, and skipping doses all risk loss of seizure control or toxicity.

111. A 38-year-old woman with relapsing-remitting multiple sclerosis reports a transient electric shock-like sensation running down her spine and into her limbs whenever she flexes her neck forward. Which clinical sign does this describe?
     • Uhthoff phenomenon
     • Brudzinski sign
     • Lhermitte sign
     • Kernig sign

     Correct answer: Lhermitte sign

     Lhermitte sign is the answer because a brief electric shock-like sensation traveling down the spine and limbs on neck flexion reflects irritation of demyelinated cervical cord fibers, commonly seen in multiple sclerosis. The Uhthoff phenomenon is heat-related symptom worsening, while Brudzinski and Kernig signs are findings of meningeal irritation rather than this neck-flexion sensation.

112. A 25-year-old woman with 7 weeks of amenorrhea presents with right-sided pelvic cramping and spotting. Her initial serum beta-hCG is 1,800 mIU/mL, and transvaginal ultrasound is indeterminate with no definite intrauterine sac. She is hemodynamically stable. Which next step best clarifies whether this is a viable intrauterine pregnancy or an ectopic gestation?
     • Proceed directly to diagnostic laparoscopy
     • Repeat the serum beta-hCG in 48 hours and compare the rate of rise
     • Administer single-dose methotrexate empirically
     • Reassure and recheck in four weeks

     Correct answer: Repeat the serum beta-hCG in 48 hours and compare the rate of rise

     Repeating the serum beta-hCG in 48 hours is the best next step. In a stable patient with an indeterminate ultrasound and an hCG near the discriminatory zone, a normal intrauterine pregnancy should show an appropriate minimal rise over 48 hours, whereas an abnormal plateau or slow rise suggests ectopic or nonviable pregnancy. Empiric methotrexate without confirming the pregnancy is nonviable could harm a desired intrauterine gestation, and immediate surgery is unwarranted in a stable patient.

113. A 27-year-old woman is found to have a tubal ectopic pregnancy and is treated with single-dose intramuscular methotrexate. The clinician schedules follow-up beta-hCG measurements to confirm the treatment is working. Between day 4 and day 7 after methotrexate, what change in beta-hCG indicates an adequate response?
     • Any continued rise above the baseline value
     • A decline of at least 15 percent
     • A return to an undetectable level by day 7
     • An unchanged value within 5 percent of baseline

     Correct answer: A decline of at least 15 percent

     A decline of at least 15 percent between day 4 and day 7 indicates an adequate response. Beta-hCG often rises initially after methotrexate, so the day 4 value is used as the reference, and a drop of 15 percent or more from day 4 to day 7 signals success; if this threshold is not met, a second dose or surgery is considered. Levels do not normally fall to undetectable within a week, so that expectation is incorrect.

114. A 31-year-old woman is being evaluated for risk factors before fertility treatment. Which of the following is the strongest established risk factor for a future ectopic pregnancy?
     • Prior history of pelvic inflammatory disease with tubal damage
     • Use of combined oral contraceptives
     • First-degree family history of breast cancer
     • A single prior uncomplicated vaginal delivery

     Correct answer: Prior history of pelvic inflammatory disease with tubal damage

     A prior history of pelvic inflammatory disease with tubal damage is the strongest risk factor. Tubal scarring from prior salpingitis impairs ovum transport and is one of the most important predisposing conditions for ectopic implantation, along with prior ectopic pregnancy and tubal surgery. Combined oral contraceptives reduce overall pregnancy risk and are not a risk factor, and an uncomplicated prior delivery does not raise ectopic risk.

115. A 29-year-old woman at 36 weeks gestation is found to have a blood pressure of 150/96 mmHg with no proteinuria and no symptoms. She had normal blood pressures earlier in pregnancy and before conception. Which diagnosis best fits these findings?
     • Chronic hypertension
     • Preeclampsia with severe features
     • Gestational hypertension
     • Eclampsia

     Correct answer: Gestational hypertension

     Gestational hypertension best fits. New-onset hypertension after 20 weeks gestation without proteinuria or other features of end-organ involvement defines gestational hypertension. Chronic hypertension would have been present before 20 weeks or before pregnancy, and preeclampsia requires proteinuria or severe features such as markedly elevated pressures or laboratory abnormalities, which are absent here.

116. A 33-year-old woman with a history of prior preeclampsia is now pregnant again and asks how to lower her risk this time. Which intervention has the best evidence for reducing the risk of recurrent preeclampsia when started in the first trimester?
     • High-dose vitamin C and E supplementation
     • Strict bed rest beginning at 12 weeks
     • Low-dose aspirin
     • Routine magnesium supplementation throughout pregnancy

     Correct answer: Low-dose aspirin

     Low-dose aspirin has the best evidence. Initiating low-dose aspirin late in the first trimester reduces the incidence of preeclampsia in women at increased risk, including those with a prior history of the disease. Antioxidant vitamins have not been shown to prevent preeclampsia, and bed rest and routine magnesium supplementation are not effective preventive measures.

117. A 30-year-old woman at 33 weeks with preeclampsia develops a platelet count of 88,000, AST of 220 U/L, and right upper quadrant pain with hemolysis on smear. Which complication of preeclampsia does this laboratory and clinical pattern represent?
     • HELLP syndrome
     • Disseminated gonococcal infection
     • Acute fatty liver of pregnancy with hypoglycemia only
     • Gestational thrombocytopenia alone

     Correct answer: HELLP syndrome

     This pattern represents HELLP syndrome. HELLP is a severe variant of preeclampsia defined by Hemolysis, Elevated Liver enzymes, and Low Platelets, often with right upper quadrant pain, and it warrants prompt delivery. Gestational thrombocytopenia is isolated and mild without hemolysis or transaminase elevation, so it does not explain this constellation of findings.

118. A 24-year-old sexually active woman presents with lower abdominal pain. On bimanual exam she has cervical motion tenderness and bilateral adnexal tenderness, with a temperature of 38.4 C. She is well-appearing and tolerating oral intake. According to current outpatient management of pelvic inflammatory disease, which regimen is appropriate empiric therapy?
     • Oral metronidazole alone
     • Oral azithromycin single dose alone
     • Intramuscular ceftriaxone plus oral doxycycline, with metronidazole
     • Oral fluconazole plus topical clotrimazole

     Correct answer: Intramuscular ceftriaxone plus oral doxycycline, with metronidazole

     Intramuscular ceftriaxone plus oral doxycycline, with metronidazole, is appropriate empiric outpatient therapy. PID is polymicrobial, so coverage must include gonorrhea, chlamydia, and anaerobes, which this regimen provides. Single-agent metronidazole or azithromycin does not adequately cover the typical pathogens, and antifungal therapy treats vulvovaginal candidiasis rather than an ascending pelvic infection.

119. A 26-year-old woman with pelvic inflammatory disease develops worsening right upper quadrant pain with tenderness over the liver in addition to her pelvic symptoms. Which complication of PID does this perihepatic involvement represent?
     • Fitz-Hugh-Curtis syndrome
     • Mittelschmerz
     • Ovarian hyperstimulation syndrome
     • Asherman syndrome

     Correct answer: Fitz-Hugh-Curtis syndrome

     This represents Fitz-Hugh-Curtis syndrome. Perihepatitis from ascending pelvic infection produces right upper quadrant pain and characteristic violin-string adhesions between the liver capsule and abdominal wall. Mittelschmerz is benign midcycle ovulatory pain, and Asherman syndrome refers to intrauterine adhesions, neither of which involves perihepatic inflammation.

120. A 34-year-old woman with cyclic pelvic pain and infertility is suspected of having endometriosis. Beyond the cyclic pain, which additional symptom is most characteristic of this condition?
     • Postcoital fever and chills
     • Dyschezia, or pain with bowel movements during menses
     • Galactorrhea
     • Intermittent visual loss

     Correct answer: Dyschezia, or pain with bowel movements during menses

     Dyschezia, or pain with bowel movements during menses, is most characteristic. Endometrial implants on or near the rectovaginal area cause cyclic pain with defecation, complementing the typical features of dysmenorrhea, deep dyspareunia, and infertility. Galactorrhea points toward a prolactin disorder, and postcoital fever suggests infection rather than the noninfectious inflammatory process of endometriosis.

121. A 28-year-old woman with biopsy-confirmed endometriosis has completed childbearing and continues to have severe pain despite combined oral contraceptives and NSAIDs. Which medical therapy works by suppressing ovarian estrogen production to induce a hypoestrogenic state?
     • Metformin
     • Levothyroxine
     • Tranexamic acid
     • A GnRH agonist such as leuprolide

     Correct answer: A GnRH agonist such as leuprolide

     A GnRH agonist such as leuprolide is the correct choice. GnRH agonists downregulate pituitary gonadotropin release, lowering ovarian estrogen and shrinking estrogen-dependent endometriotic implants, which relieves pain when first-line hormonal therapy fails. Tranexamic acid reduces menstrual blood loss but does not suppress implants, and metformin and levothyroxine treat unrelated endocrine conditions.

122. A 49-year-old woman undergoes a screening mammogram that reveals a cluster of pleomorphic microcalcifications in an area she cannot feel. There is no palpable mass. Which next step is most appropriate to evaluate this finding?
     • Repeat mammogram in one year
     • Stereotactic core needle biopsy of the calcifications
     • Begin tamoxifen empirically
     • Bilateral mastectomy

     Correct answer: Stereotactic core needle biopsy of the calcifications

     Stereotactic core needle biopsy of the calcifications is most appropriate. Suspicious clustered pleomorphic microcalcifications can represent ductal carcinoma in situ or early invasive cancer, so image-guided tissue sampling is needed for diagnosis. Deferring with a one-year mammogram risks missing malignancy, and empiric treatment or surgery without a tissue diagnosis is premature.

123. A 36-year-old woman has a mother and sister who both developed breast cancer before age 45. Genetic testing reveals a pathogenic BRCA1 mutation. Which screening recommendation is appropriate for a woman with this high-risk genetic profile?
     • No screening until age 50
     • Clinical breast exam only, every five years
     • Annual breast MRI in addition to mammography, beginning at a younger age
     • Mammography every five years starting at 60

     Correct answer: Annual breast MRI in addition to mammography, beginning at a younger age

     Annual breast MRI in addition to mammography, beginning at a younger age, is appropriate. Women with BRCA mutations or a strong family history have a substantially elevated lifetime risk, so enhanced surveillance with both MRI and mammography starting earlier than the general population is recommended. Delaying screening to age 50 or 60 or using infrequent intervals is inadequate for this high-risk group.

124. A 32-year-old breastfeeding woman presents with a tender, erythematous, wedge-shaped area on one breast, fever, and body aches that began two days ago. She has no fluctuant mass. Which diagnosis and initial management are most appropriate?
     • Inflammatory breast cancer requiring immediate biopsy
     • Lactational mastitis treated with continued breastfeeding and antibiotics covering Staphylococcus aureus
     • Fibroadenoma requiring excision
     • Breast abscess requiring incision and drainage now

     Correct answer: Lactational mastitis treated with continued breastfeeding and antibiotics covering Staphylococcus aureus

     Lactational mastitis treated with continued breastfeeding and antibiotics covering Staphylococcus aureus is most appropriate. A focal erythematous, tender wedge of breast with systemic symptoms in a lactating woman without a fluctuant collection is typical of mastitis, and continued milk drainage plus anti-staphylococcal antibiotics is the standard approach. The absence of a fluctuant mass argues against an abscess needing drainage, and the acute infectious picture is not consistent with cancer or fibroadenoma.

125. A 23-year-old woman is diagnosed with polycystic ovary syndrome. Beyond reproductive symptoms, screening for which associated metabolic abnormality is most important in her long-term care?
     • Insulin resistance and type 2 diabetes
     • Hypocalcemia
     • Iron overload
     • Primary hyperparathyroidism

     Correct answer: Insulin resistance and type 2 diabetes

     Insulin resistance and type 2 diabetes screening is most important. PCOS is strongly associated with insulin resistance, impaired glucose tolerance, and an elevated risk of type 2 diabetes, so glucose screening is a core component of management. Hypocalcemia, iron overload, and hyperparathyroidism are not characteristic metabolic complications of PCOS.

126. A 27-year-old woman with polycystic ovary syndrome wishes to conceive. After lifestyle measures, which oral medication is now recommended as first-line for ovulation induction in PCOS?
     • Spironolactone
     • Letrozole
     • Combined oral contraceptives
     • Levothyroxine

     Correct answer: Letrozole

     Letrozole is recommended as first-line for ovulation induction in PCOS. An aromatase inhibitor, letrozole produces higher live birth rates than clomiphene in women with PCOS and is now preferred for this purpose. Combined oral contraceptives prevent rather than induce ovulation, and spironolactone is used for hyperandrogenic symptoms, not fertility.

127. A 21-year-old woman presents for her first cervical cancer screening. According to current screening guidance, at what age should cervical cancer screening with cytology generally begin for average-risk women?
     • At the onset of sexual activity regardless of age
     • Age 18
     • Age 21
     • Age 30

     Correct answer: Age 21

     Cervical cancer screening with cytology generally begins at age 21. Per the USPSTF, screening starts at age 21 regardless of the age of sexual debut, because cervical cancer is rare before this age and earlier screening leads to overtreatment of lesions likely to regress. Beginning at the onset of sexual activity or at age 18 is no longer recommended.

128. A 35-year-old woman's cervical cytology returns as atypical squamous cells of undetermined significance (ASC-US), and reflex high-risk HPV testing is positive. Which is the most appropriate next step in managing this result?
     • Repeat cytology in five years
     • Immediate hysterectomy
     • Reassurance with no further evaluation
     • Colposcopy

     Correct answer: Colposcopy

     Colposcopy is the most appropriate next step. An ASC-US result with positive high-risk HPV co-testing carries enough risk of underlying high-grade dysplasia to warrant direct visualization and biopsy of the cervix by colposcopy. Returning to routine screening or simply reassuring the patient would inappropriately delay detection of a potential precancerous lesion.

129. A 28-year-old woman at 30 weeks gestation presents with sudden painless vaginal bleeding. She is hemodynamically stable and the fetal heart rate is reassuring. A transabdominal ultrasound suggests the placenta is near the cervix. Which examination should be deliberately avoided until placenta previa has been excluded?
     • Maternal blood pressure measurement
     • Digital cervical examination
     • External fetal heart rate monitoring
     • Maternal complete blood count

     Correct answer: Digital cervical examination

     A digital cervical examination should be avoided. In suspected placenta previa, inserting a finger into the cervix can disrupt the low-lying placenta and provoke catastrophic hemorrhage, so it is contraindicated until previa is excluded by ultrasound. Blood pressure measurement, fetal monitoring, and laboratory testing are safe and indicated parts of the evaluation.

130. A 34-year-old woman at 31 weeks with chronic hypertension presents with continuous severe abdominal pain and a firm, tender, contracting uterus, along with dark vaginal bleeding. The fetal heart tracing shows late decelerations. Which condition does this presentation most strongly suggest?
     • Placenta previa
     • Placental abruption
     • Braxton Hicks contractions
     • Cervical insufficiency

     Correct answer: Placental abruption

     Placental abruption is most strongly suggested. Painful dark bleeding with a tense, tender, contracting uterus and fetal distress in a woman with hypertension is the classic picture of premature placental separation. Placenta previa causes painless bright red bleeding with a soft, nontender uterus, which is the opposite pattern, and Braxton Hicks contractions are painless and not associated with bleeding.

131. A 50-year-old woman reports irregular, increasingly infrequent menstrual periods over the past two years, accompanied by hot flashes and sleep disruption. She still has occasional periods. Which term best describes this transitional phase?
     • Perimenopause
     • Premature ovarian insufficiency
     • Postmenopause
     • Secondary amenorrhea

     Correct answer: Perimenopause

     Perimenopause best describes this phase. The menopausal transition is marked by fluctuating ovarian function with irregular cycles and vasomotor symptoms while menses still occur, preceding the final menstrual period. Postmenopause requires 12 consecutive months without menses, and premature ovarian insufficiency refers to ovarian failure before age 40, which does not apply at age 50.

132. A 53-year-old postmenopausal woman with bothersome hot flashes and an intact uterus is considering systemic hormone therapy. To prevent endometrial hyperplasia, which addition to estrogen is necessary in a woman who has not had a hysterectomy?
     • A progestin
     • An additional androgen
     • A bisphosphonate
     • Supplemental thyroid hormone

     Correct answer: A progestin

     A progestin is necessary. In a woman with an intact uterus, unopposed estrogen stimulates the endometrium and increases the risk of endometrial hyperplasia and carcinoma, so a progestin must be added to provide endometrial protection. Bisphosphonates, androgens, and thyroid hormone do not protect the endometrium from estrogenic stimulation.

133. A 40-year-old woman reports heavy menstrual bleeding and pelvic pressure. Examination shows an enlarged, irregular, firm, nontender uterus, and ultrasound demonstrates discrete well-circumscribed hypoechoic myometrial masses. Which diagnosis best accounts for these findings?
     • Ovarian torsion
     • Uterine leiomyomas
     • Pelvic inflammatory disease
     • Bartholin gland cyst

     Correct answer: Uterine leiomyomas

     Uterine leiomyomas best account for these findings. An enlarged, irregular, firm, nontender uterus with discrete hypoechoic myometrial masses and heavy menstrual bleeding is characteristic of fibroids, the most common benign uterine tumors. PID would present with fever and cervical motion tenderness, and a Bartholin gland cyst is a vulvar finding unrelated to uterine enlargement.

134. A 44-year-old woman has a symmetrically enlarged, globular, tender uterus with heavy and painful menses. Ultrasound shows diffuse myometrial thickening without discrete masses, and MRI reveals a thickened junctional zone. Which diagnosis is most consistent with these findings?
     • Adenomyosis
     • Endometrial polyp
     • Uterine leiomyoma
     • Ovarian cyst

     Correct answer: Adenomyosis

     Adenomyosis is most consistent. Adenomyosis arises from endometrial glands within the myometrium and produces a diffusely enlarged, boggy, tender uterus with heavy painful menses and a thickened junctional zone on MRI. Leiomyomas instead form discrete firm masses, distinguishing them from the diffuse symmetric enlargement seen in adenomyosis.

135. A 60-year-old woman who completed menopause eight years ago reports a single episode of vaginal bleeding. Which statement best reflects the appropriate clinical approach to postmenopausal bleeding?
     • It is usually benign atrophy and requires no workup
     • It should be evaluated to exclude endometrial carcinoma
     • It indicates a return of normal ovulatory cycles
     • It is best managed by starting combined oral contraceptives

     Correct answer: It should be evaluated to exclude endometrial carcinoma

     Postmenopausal bleeding should be evaluated to exclude endometrial carcinoma. Any bleeding after menopause is considered endometrial cancer until proven otherwise and warrants endometrial assessment such as biopsy or transvaginal ultrasound, even though atrophy is the most common ultimate cause. Dismissing it without workup risks missing a curable malignancy.

136. A 17-year-old has never had a menstrual period. She has normal breast and pubic hair development and a normal growth pattern. Which term correctly classifies her presentation?
     • Secondary amenorrhea
     • Oligomenorrhea
     • Primary amenorrhea
     • Menorrhagia

     Correct answer: Primary amenorrhea

     Primary amenorrhea correctly classifies this presentation. Primary amenorrhea is defined as the absence of menarche by age 15 with normal secondary sexual characteristics, or by age 13 without such development, prompting evaluation for anatomic or endocrine causes. Secondary amenorrhea refers to cessation of previously established menses, which does not apply because she has never menstruated.

137. A 22-year-old woman reports severe cramping lower abdominal pain that consistently begins with the onset of menses and resolves over a few days, without abnormal exam findings or pelvic pathology. Which diagnosis and first-line therapy are most appropriate?
     • Secondary dysmenorrhea best treated with antibiotics
     • Endometrial carcinoma best treated with hysterectomy
     • Ectopic pregnancy best treated with methotrexate
     • Primary dysmenorrhea best treated with NSAIDs

     Correct answer: Primary dysmenorrhea best treated with NSAIDs

     Primary dysmenorrhea best treated with NSAIDs is most appropriate. Primary dysmenorrhea is painful menses without underlying pelvic pathology, driven by prostaglandin-mediated uterine contractions, and NSAIDs that inhibit prostaglandin synthesis are first-line therapy, with combined hormonal contraceptives as an alternative. Secondary dysmenorrhea implies an identifiable disorder such as endometriosis or fibroids, which is not present here.

138. A 19-year-old woman presents with a thin, off-white, homogeneous vaginal discharge with a fishy odor that intensifies after a drop of potassium hydroxide is added to a sample. Wet mount shows epithelial cells studded with adherent bacteria. Which diagnosis do these findings represent?
     • Bacterial vaginosis
     • Vulvovaginal candidiasis
     • Trichomoniasis
     • Atrophic vaginitis

     Correct answer: Bacterial vaginosis

     Bacterial vaginosis is represented by these findings. A thin homogeneous discharge with a positive whiff test on potassium hydroxide and clue cells on wet mount satisfies the Amsel criteria for bacterial vaginosis. Candidiasis causes a thick white discharge with pruritus, and trichomoniasis classically produces a frothy discharge with motile flagellated organisms, distinguishing them from this presentation.

139. A 26-year-old woman is found to have a tubal ectopic pregnancy. Which historical factor in her chart is most strongly associated with the location of the ectopic and would have been protective if it were a different method?
     • Daily folic acid use
     • A prior cesarean delivery
     • Presence of an intrauterine device in place at conception
     • A history of seasonal allergies

     Correct answer: Presence of an intrauterine device in place at conception

     The presence of an intrauterine device in place at conception is most strongly associated with this scenario. While an IUD is highly effective at preventing pregnancy overall, when a pregnancy does occur with an IUD in place, it is disproportionately likely to be ectopic because the device prevents intrauterine implantation more effectively than tubal implantation. Folic acid use and seasonal allergies have no bearing on ectopic location.

140. A 48-year-old woman with rheumatoid arthritis has a normocytic anemia. Laboratory studies show a low serum iron, a high ferritin, and a low total iron-binding capacity. Which mechanism best explains this anemia?
     • Hepcidin-mediated sequestration of iron within macrophages
     • Chronic gastrointestinal blood loss depleting iron stores
     • Antibody-mediated destruction of circulating red cells
     • A clonal failure of the bone marrow stem cells

     Correct answer: Hepcidin-mediated sequestration of iron within macrophages

     Hepcidin-mediated sequestration of iron explains anemia of chronic disease. In chronic inflammation, elevated hepcidin traps iron inside macrophages and blocks intestinal absorption, producing a low serum iron with a paradoxically high ferritin and a low total iron-binding capacity. Chronic blood loss would deplete stores and lower ferritin while raising TIBC, antibody-mediated destruction describes hemolysis with a high reticulocyte count, and clonal marrow failure describes aplastic anemia with pancytopenia.

141. A 30-year-old man of Mediterranean descent is found to have a mild microcytic anemia. His mean corpuscular volume is disproportionately low for the modest reduction in hemoglobin, the red cell count is elevated, and ferritin is normal. Which test best confirms the suspected diagnosis?
     • Serum total iron-binding capacity
     • Bone marrow biopsy with iron stain
     • Direct antiglobulin (Coombs) test
     • Hemoglobin electrophoresis

     Correct answer: Hemoglobin electrophoresis

     Hemoglobin electrophoresis best confirms beta-thalassemia trait, suggested here by a microcytosis out of proportion to a mild anemia, a high red cell count, and normal iron stores. Electrophoresis classically shows an elevated hemoglobin A2. Total iron-binding capacity helps separate iron deficiency from chronic disease but does not diagnose a hemoglobinopathy, a marrow biopsy is unnecessary, and the Coombs test evaluates immune hemolysis rather than a structural hemoglobin disorder.

142. A 60-year-old man undergoes routine labs that reveal a hemoglobin of 19 g/dL and a hematocrit of 58 percent. He reports generalized itching after hot showers and has a palpable spleen. A JAK2 V617F mutation is identified. Which is the cornerstone of initial management?
     • Therapeutic phlebotomy
     • Iron supplementation
     • Packed red blood cell transfusion
     • Erythropoietin injections

     Correct answer: Therapeutic phlebotomy

     Therapeutic phlebotomy is the cornerstone of managing polycythemia vera, the JAK2-driven myeloproliferative disorder suggested by erythrocytosis, aquagenic pruritus, and splenomegaly. Lowering the hematocrit reduces hyperviscosity and thrombotic risk, and low-dose aspirin is added. Iron supplementation would worsen red cell overproduction, transfusion would dangerously raise the hematocrit, and erythropoietin would stimulate further erythrocytosis, the opposite of the therapeutic goal.

143. A 9-month-old infant of West African ancestry presents with painful, symmetric swelling of the hands and feet. Newborn screening had documented hemoglobin SS disease. Which complication does this presentation most likely represent?
     • Dactylitis (hand-foot syndrome)
     • Splenic sequestration crisis
     • Aplastic crisis from parvovirus B19
     • Osteomyelitis from Salmonella

     Correct answer: Dactylitis (hand-foot syndrome)

     Dactylitis, or hand-foot syndrome, is the painful symmetric swelling of the hands and feet that is frequently the earliest vaso-occlusive manifestation of sickle cell disease in infancy. It results from microvascular occlusion in the small bones. Splenic sequestration presents with a rapidly enlarging spleen and a falling hemoglobin, aplastic crisis from parvovirus B19 causes a sudden drop in reticulocytes, and Salmonella osteomyelitis produces focal bone infection with fever rather than symmetric digital swelling.

144. A 25-year-old with sickle cell disease is due for routine health maintenance. Because of functional asplenia, which preventive measure is most important to reduce the risk of overwhelming infection?
     • Annual abdominal ultrasound of the spleen
     • Vaccination against encapsulated organisms including pneumococcus, meningococcus, and Haemophilus influenzae type b
     • Prophylactic anticoagulation with a direct oral anticoagulant
     • Routine red cell exchange transfusion every month

     Correct answer: Vaccination against encapsulated organisms including pneumococcus, meningococcus, and Haemophilus influenzae type b

     Vaccinating against encapsulated organisms is the most important preventive step because functional asplenia in sickle cell disease leaves patients highly vulnerable to pneumococcus, meningococcus, and Haemophilus influenzae type b. The spleen normally clears these bacteria, so immunization and, in children, penicillin prophylaxis are essential. Abdominal ultrasound does not prevent infection, anticoagulation does not address asplenia, and routine monthly exchange transfusion is reserved for specific indications such as stroke prevention.

145. A 6-year-old child develops widespread petechiae and gum bleeding two weeks after a viral upper respiratory infection. The platelet count is 9,000/microL, but the child is otherwise well with no hepatosplenomegaly and a normal hemoglobin and white count. Which initial approach is most appropriate for this typically self-limited disorder?
     • Emergency splenectomy
     • Immediate platelet transfusion as definitive cure
     • Lifelong romiplostim therapy
     • Observation or corticosteroids/IVIG depending on bleeding severity

     Correct answer: Observation or corticosteroids/IVIG depending on bleeding severity

     Observation, or corticosteroids and IVIG when bleeding warrants, is the appropriate initial approach to childhood immune thrombocytopenic purpura, which often follows a viral illness and is usually self-limited. Many children recover spontaneously, and therapy is guided by bleeding rather than the platelet number alone. Splenectomy is reserved for refractory chronic disease, platelet transfusion is reserved for life-threatening hemorrhage because transfused platelets are quickly destroyed, and thrombopoietin agonists are second-line agents.

146. A 56-year-old patient in septic shock develops oozing from venipuncture sites and new ecchymoses. Laboratory studies show a low platelet count, prolonged PT and aPTT, a low fibrinogen, and markedly elevated D-dimer. Which condition do these findings indicate?
     • Immune thrombocytopenic purpura
     • Hemophilia A
     • Disseminated intravascular coagulation
     • Von Willebrand disease

     Correct answer: Disseminated intravascular coagulation

     Disseminated intravascular coagulation is identified by thrombocytopenia with prolonged PT and aPTT, a low fibrinogen, and a high D-dimer in a critically ill patient. Widespread activation of coagulation consumes platelets and clotting factors while fibrinolysis releases D-dimer, producing simultaneous bleeding and microthrombosis. Immune thrombocytopenic purpura shows isolated low platelets with normal coagulation times, hemophilia A prolongs only the aPTT, and von Willebrand disease does not consume fibrinogen.

147. A 30-year-old man begins induction chemotherapy for newly diagnosed acute promyelocytic leukemia, a subtype defined by the t(15;17) translocation. Which targeted agent is the cornerstone of treatment for this leukemia?
     • Imatinib
     • Rituximab
     • All-trans retinoic acid
     • Hydroxyurea

     Correct answer: All-trans retinoic acid

     All-trans retinoic acid is the cornerstone of treating acute promyelocytic leukemia, the subtype caused by the t(15;17) translocation that fuses the PML and RARA genes. The agent forces the arrested promyelocytes to differentiate, dramatically improving survival, and is often paired with arsenic trioxide. Imatinib targets the BCR-ABL kinase of chronic myelogenous leukemia, rituximab targets CD20 B cells, and hydroxyurea is used for cytoreduction in myeloproliferative disorders rather than as APL-directed therapy.

148. A 67-year-old man presents with fatigue, easy bruising, and frequent infections. The complete blood count shows pancytopenia, and the peripheral smear reveals circulating myeloblasts, some containing Auer rods. Which leukemia does this finding identify?
     • Acute myelogenous leukemia
     • Chronic lymphocytic leukemia
     • Acute lymphoblastic leukemia
     • Hairy cell leukemia

     Correct answer: Acute myelogenous leukemia

     Auer rods within circulating myeloblasts are characteristic of acute myelogenous leukemia, the most common acute leukemia of adults, presenting here with pancytopenia and marrow failure. These needle-like inclusions are aggregates of azurophilic granules specific to the myeloid lineage. Chronic lymphocytic leukemia shows mature lymphocytes with smudge cells, acute lymphoblastic leukemia features lymphoblasts and predominates in children, and hairy cell leukemia shows lymphocytes with cytoplasmic projections rather than Auer rods.

149. A patient on warfarin presents with an INR of 5.2 and no bleeding. According to current anticoagulation management principles, which approach is most appropriate?
     • Administer intravenous vitamin K and four-factor prothrombin complex concentrate
     • Give fresh frozen plasma to normalize the INR rapidly
     • Double the warfarin dose to overcome resistance
     • Hold one or more warfarin doses and recheck the INR, resuming at a lower dose

     Correct answer: Hold one or more warfarin doses and recheck the INR, resuming at a lower dose

     Holding warfarin doses, rechecking the INR, and resuming at a lower dose is appropriate for an INR modestly above range without bleeding. For an INR below roughly 9 without hemorrhage, omitting doses generally suffices without vitamin K. Intravenous vitamin K and prothrombin complex concentrate are reserved for serious or life-threatening bleeding, fresh frozen plasma is used for active bleeding requiring rapid reversal, and increasing the dose would dangerously worsen the supratherapeutic state.

150. A 72-year-old woman with atrial fibrillation and an estimated creatinine clearance of 25 mL/min needs anticoagulation. Which consideration most directly affects the choice and dosing of a direct oral anticoagulant in this patient?
     • Dietary vitamin K intake must be tightly controlled
     • Renal function must be assessed because clearance influences drug selection and dose adjustment
     • Routine INR monitoring is required to titrate the dose
     • Protamine sulfate must be available for reversal

     Correct answer: Renal function must be assessed because clearance influences drug selection and dose adjustment

     Assessing renal function is essential because direct oral anticoagulants undergo varying degrees of renal elimination, so reduced clearance influences agent selection and dose adjustment and may contraindicate certain drugs. Dietary vitamin K matters for warfarin, not DOACs; DOACs do not require routine INR monitoring; and protamine reverses heparin, not the oral agents, which have their own targeted antidotes.

151. A 35-year-old woman with celiac disease has a macrocytic anemia, an elevated mean corpuscular volume, and hypersegmented neutrophils, but no neurologic symptoms. Serum folate is low and vitamin B12 is normal. Before attributing the anemia solely to folate deficiency, why must B12 status be confirmed prior to repletion?
     • Folate supplementation can correct the anemia while allowing B12-related neurologic damage to progress
     • Folate and B12 cannot be measured simultaneously in the same patient
     • Folate repletion causes iron overload if B12 is low
     • B12 deficiency always raises the folate level falsely

     Correct answer: Folate supplementation can correct the anemia while allowing B12-related neurologic damage to progress

     Confirming B12 status before folate repletion matters because giving folate alone can reverse the megaloblastic anemia while unmasked B12 deficiency continues to cause irreversible neurologic injury. The hematologic improvement masks ongoing demyelination. Folate and B12 are routinely measured together, folate does not cause iron overload, and B12 deficiency does not reliably elevate folate, so those alternatives do not explain the clinical caution.

152. A 50-year-old woman with autoimmune hypothyroidism develops a macrocytic anemia. Testing reveals low vitamin B12, anti-intrinsic factor antibodies, and atrophic gastritis. Which underlying mechanism explains her deficiency?
     • Inadequate dietary intake of animal products
     • Autoimmune destruction of gastric parietal cells reducing intrinsic factor
     • Increased renal excretion of cobalamin
     • Bacterial overgrowth consuming dietary folate

     Correct answer: Autoimmune destruction of gastric parietal cells reducing intrinsic factor

     Autoimmune destruction of gastric parietal cells with loss of intrinsic factor causes pernicious anemia, the mechanism indicated by anti-intrinsic factor antibodies and atrophic gastritis in a patient with other autoimmune disease. Without intrinsic factor, B12 cannot be absorbed in the terminal ileum. Dietary insufficiency is uncommon outside strict veganism, cobalamin is not lost renally in this disorder, and bacterial overgrowth affects B12 rather than folate in this scenario.

153. A 19-year-old man of Mediterranean ancestry develops sudden jaundice, dark urine, and fatigue several days after starting an antimalarial. The smear shows bite cells and Heinz bodies, and an enzyme assay confirms the diagnosis once the acute episode resolves. Which deficiency is responsible?
     • Pyruvate kinase deficiency
     • Hereditary spherocytosis
     • Paroxysmal nocturnal hemoglobinuria
     • Glucose-6-phosphate dehydrogenase deficiency

     Correct answer: Glucose-6-phosphate dehydrogenase deficiency

     Glucose-6-phosphate dehydrogenase deficiency produces episodic hemolysis triggered by oxidative stressors such as certain drugs, infections, or fava beans, with bite cells and Heinz bodies on the smear. The enzyme defect leaves red cells unable to handle oxidative injury. Enzyme assays are best timed after the acute episode because young reticulocytes can give falsely normal results. Pyruvate kinase deficiency and hereditary spherocytosis are not classically drug-triggered with Heinz bodies, and paroxysmal nocturnal hemoglobinuria has a different mechanism.

154. A 28-year-old woman with longstanding lupus develops worsening fatigue, jaundice, and scleral icterus. Laboratory studies show anemia, reticulocytosis, an elevated indirect bilirubin, and a positive direct antiglobulin (Coombs) test. Which form of hemolytic anemia is most likely?
     • Microangiopathic hemolytic anemia
     • Warm autoimmune hemolytic anemia
     • Glucose-6-phosphate dehydrogenase deficiency
     • Sickle cell anemia

     Correct answer: Warm autoimmune hemolytic anemia

     Warm autoimmune hemolytic anemia is most likely given a positive direct antiglobulin test with reticulocytosis and indirect hyperbilirubinemia in a patient with lupus, an autoimmune disorder that commonly drives IgG-mediated red cell destruction. The Coombs test confirms antibody coating of erythrocytes. Microangiopathic hemolysis is Coombs-negative with schistocytes, G6PD deficiency is an enzyme defect that is Coombs-negative, and sickle cell anemia is a hemoglobinopathy unrelated to a positive antiglobulin test.

155. A 5-year-old boy with hemophilia A presents with a tense, painful, swollen knee after minor activity and no external wound. Which intervention is most appropriate for this acute hemarthrosis?
     • Factor VIII concentrate replacement
     • Aspirin for analgesia
     • Platelet transfusion
     • Fresh frozen plasma as first-line therapy

     Correct answer: Factor VIII concentrate replacement

     Factor VIII concentrate replacement is the appropriate treatment for an acute hemarthrosis in hemophilia A, directly correcting the deficient clotting factor to stop the bleed and protect the joint. Aspirin impairs platelet function and is contraindicated in bleeding disorders, platelet transfusion does not address a factor deficiency with normal platelet counts, and fresh frozen plasma is far less efficient and not the preferred therapy when specific factor concentrate is available.

156. A 4-year-old boy has recurrent deep bleeding episodes. Coagulation studies show a prolonged aPTT with a normal PT and platelet count. Factor VIII activity is normal, but factor IX activity is markedly reduced. Which disorder do these results identify?
     • Hemophilia A
     • Hemophilia B
     • Von Willebrand disease
     • Factor V Leiden

     Correct answer: Hemophilia B

     Hemophilia B, the X-linked deficiency of factor IX, is identified by an isolated prolonged aPTT with reduced factor IX activity but normal factor VIII. Both hemophilia A and B share an identical coagulation profile and clinical picture, so distinguishing them requires specific factor assays. Hemophilia A is a factor VIII deficiency, von Willebrand disease involves abnormal von Willebrand factor with platelet dysfunction, and factor V Leiden is a thrombophilia that causes clotting rather than bleeding.

157. A 32-year-old woman with recurrent unprovoked deep vein thromboses and a first-degree relative with venous thromboembolism is evaluated for an inherited thrombophilia. Which is the most common inherited cause of hypercoagulability in this population?
     • Antithrombin III deficiency
     • Protein C deficiency
     • Factor V Leiden mutation
     • Prothrombin G20210A mutation

     Correct answer: Factor V Leiden mutation

     The factor V Leiden mutation is the most common inherited thrombophilia, causing activated protein C resistance so that factor V is not properly inactivated and clotting proceeds unchecked. It accounts for the majority of hereditary hypercoagulable cases. Antithrombin III and protein C deficiencies are far less common, and the prothrombin G20210A mutation is the second most frequent inherited thrombophilia but still less prevalent than factor V Leiden.

158. A 70-year-old man reports six months of fatigue and back pain. Workup shows a normocytic anemia, rouleaux formation on the peripheral smear, an elevated total protein with a narrow monoclonal band on serum protein electrophoresis, and renal insufficiency. Which laboratory feature most directly reflects the malignant clone in multiple myeloma?
     • Rouleaux formation alone
     • A monoclonal (M) protein spike on serum protein electrophoresis
     • Microcytosis of the red cells
     • Elevated reticulocyte count

     Correct answer: A monoclonal (M) protein spike on serum protein electrophoresis

     A monoclonal protein spike on serum protein electrophoresis most directly reflects the plasma-cell clone of multiple myeloma, which secretes a single homogeneous immunoglobulin. Rouleaux formation is a nonspecific consequence of the elevated paraprotein, the anemia is typically normocytic rather than microcytic, and the marrow is suppressed so the reticulocyte count is low rather than elevated. Identifying the M protein is central to the diagnostic workup.

159. A 26-year-old man presents with a rapidly enlarging abdominal mass, and biopsy of an aggressive B-cell non-Hodgkin lymphoma shows a high mitotic rate with a starry-sky appearance. Which urgent metabolic complication is this highly proliferative lymphoma especially likely to cause once chemotherapy begins?
     • Tumor lysis syndrome
     • Hypothyroidism
     • Iron deficiency anemia
     • Vitamin K deficiency

     Correct answer: Tumor lysis syndrome

     Tumor lysis syndrome is especially likely with this highly proliferative non-Hodgkin lymphoma showing a starry-sky pattern, because rapid cell turnover and a large tumor burden release massive intracellular contents when chemotherapy lyses the cells. The result is hyperkalemia, hyperphosphatemia, hyperuricemia, hypocalcemia, and acute kidney injury, prevented with hydration and rasburicase or allopurinol. Hypothyroidism, iron deficiency, and vitamin K deficiency are not characteristic acute complications of cytoreduction in this setting.

160. A 19-year-old woman is found to have a mild normocytic anemia with a reticulocyte count that is inappropriately low for the degree of anemia, but iron studies, B12, and folate are all normal. Which term best describes a reticulocyte response that is too low to compensate for ongoing anemia?
     • Hyperproliferative response
     • Hypoproliferative (inadequate) marrow response
     • Microangiopathic response
     • Megaloblastic maturation

     Correct answer: Hypoproliferative (inadequate) marrow response

     A reticulocyte count too low for the severity of anemia defines a hypoproliferative, or inadequate, marrow response, indicating the bone marrow is not increasing red cell production appropriately. The corrected reticulocyte count and reticulocyte production index help separate this pattern from hyperproliferative states such as hemolysis or acute blood loss, in which reticulocytes rise. A microangiopathic response describes mechanical red cell shearing, and megaloblastic maturation refers to a specific morphology rather than the magnitude of reticulocytosis.

161. A surgeon orders preoperative coagulation labs on a healthy 40-year-old man with no bleeding history. The PT is prolonged while the aPTT is normal. A deficiency of which clotting factor is most specifically associated with an isolated prolongation of the prothrombin time?
     • Factor VII
     • Factor VIII
     • Factor IX
     • Factor XII

     Correct answer: Factor VII

     An isolated prolonged prothrombin time with a normal aPTT points to a factor VII deficiency, because factor VII is the unique component of the extrinsic pathway measured by the PT. Factors VIII, IX, and XII belong to the intrinsic pathway and prolong the aPTT instead. Recognizing which pathway each test reflects allows the clinician to localize a coagulation abnormality from the pattern of the screening studies.

162. A 38-year-old woman is found to have an isolated low platelet count of 95,000/microL on a routine complete blood count, but she reports no bruising or bleeding and the remainder of the smear is unremarkable. The technician notes platelet clumping near the edge of the slide. Which step best clarifies whether this represents a true thrombocytopenia?
     • Immediately begin corticosteroids for presumed immune thrombocytopenia
     • Transfuse platelets to a safe level before any further testing
     • Order an urgent bone marrow biopsy
     • Repeat the count in a citrate tube to rule out EDTA-induced pseudothrombocytopenia

     Correct answer: Repeat the count in a citrate tube to rule out EDTA-induced pseudothrombocytopenia

     Repeating the count in a citrate tube best clarifies the result, because EDTA-induced platelet clumping produces a spuriously low automated platelet count known as pseudothrombocytopenia. Clumping noted on the smear is the clue, and a citrate-anticoagulated specimen typically yields a normal count. Starting corticosteroids or transfusing platelets would treat a nonexistent disorder, and a bone marrow biopsy is an invasive overreaction before excluding this common laboratory artifact.

163. Which serum creatinine pattern meets a diagnostic criterion for acute kidney injury?
     • A rise in serum creatinine of at least 0.3 mg/dL within 48 hours
     • A 5 percent rise in serum creatinine over 7 days
     • A stable serum creatinine maintained for one week
     • Any single creatinine value above 1.0 mg/dL

     Correct answer: A rise in serum creatinine of at least 0.3 mg/dL within 48 hours

     A rise in serum creatinine of at least 0.3 mg/dL within 48 hours is correct. Acute kidney injury is defined by an absolute increase in serum creatinine of 0.3 mg/dL or more within 48 hours, by a 1.5-fold rise from baseline within 7 days, or by a drop in urine output. A stable value over a week reflects no acute change, a 5 percent rise is too small to meet the threshold, and a single value above 1.0 mg/dL can be a normal baseline rather than evidence of acute injury.

164. A patient with acute kidney injury after severe diarrhea has a blood urea nitrogen to creatinine ratio of 28 to 1. Which category of acute kidney injury does this ratio most strongly favor?
     • Intrinsic acute tubular necrosis
     • Acute interstitial nephritis
     • Prerenal azotemia
     • Glomerulonephritis

     Correct answer: Prerenal azotemia

     Prerenal azotemia is correct. A blood urea nitrogen to creatinine ratio above about 20 to 1 reflects enhanced tubular urea reabsorption that accompanies reduced renal perfusion, as occurs after volume loss from diarrhea, the hallmark of prerenal azotemia. Acute tubular necrosis typically lowers the ratio toward 10 to 15 to 1, while interstitial nephritis and glomerulonephritis are intrinsic processes that do not characteristically raise the ratio in this way.

165. A patient develops acute kidney injury with fever, a diffuse rash, and eosinophils on urinalysis several days after starting a new antibiotic. Which form of acute kidney injury is most consistent with this picture?
     • Acute interstitial nephritis
     • Prerenal azotemia
     • Postrenal obstruction
     • Membranous nephropathy

     Correct answer: Acute interstitial nephritis

     Acute interstitial nephritis is correct. A drug-related triad of fever, rash, and eosinophilia with eosinophils in the urine appearing days after a new medication points to acute interstitial nephritis, an allergic inflammatory injury of the renal interstitium. Prerenal azotemia follows hypoperfusion, postrenal injury follows obstruction, and membranous nephropathy is a nephrotic glomerular disease without this hypersensitivity pattern.

166. A patient with suspected postrenal acute kidney injury needs an initial imaging study to look for obstruction of the urinary tract. Which test is the most appropriate first choice?
     • A plain abdominal radiograph
     • A radionuclide bone scan
     • Renal ultrasonography
     • An intravenous pyelogram with contrast

     Correct answer: Renal ultrasonography

     Renal ultrasonography is correct. Ultrasound is the preferred initial study for suspected obstructive (postrenal) acute kidney injury because it readily detects hydronephrosis without contrast or radiation risk. A plain film and bone scan do not reliably show urinary obstruction, and a contrast pyelogram exposes an already injured kidney to nephrotoxic contrast.

167. A patient with crush injuries to both legs develops acute kidney injury, dark tea-colored urine that tests positive for blood but shows no red cells microscopically, and a markedly elevated creatine kinase. Which mechanism best explains the kidney injury?
     • Immune complex deposition in the glomeruli
     • Bilateral ureteral stone obstruction
     • Allergic interstitial inflammation
     • Pigment-induced tubular injury from myoglobin

     Correct answer: Pigment-induced tubular injury from myoglobin

     Pigment-induced tubular injury from myoglobin is correct. Rhabdomyolysis from crush injury releases myoglobin, which produces a urine dipstick positive for blood without red cells and causes intrinsic acute kidney injury through tubular obstruction and direct toxicity. Glomerular immune deposition, ureteral stone obstruction, and allergic interstitial nephritis do not fit the elevated creatine kinase and pigmenturia of this presentation.

168. Which clinical scenario is an accepted indication for urgent dialysis in a patient with acute kidney injury?
     • Refractory hyperkalemia unresponsive to medical therapy
     • An isolated blood urea nitrogen of 40 mg/dL
     • A urine output of 1.5 liters per day
     • A serum creatinine of 2.0 mg/dL with normal potassium

     Correct answer: Refractory hyperkalemia unresponsive to medical therapy

     Refractory hyperkalemia unresponsive to medical therapy is correct. Life-threatening hyperkalemia that does not respond to medications is one of the classic emergent indications for dialysis, along with severe acidosis, volume overload, certain intoxications, and symptomatic uremia. A modestly elevated urea, normal urine output, and a creatinine of 2.0 with normal potassium do not by themselves require urgent dialysis.

169. When estimating the severity of acute kidney injury, which finding reflects the most advanced stage of injury under standard staging systems?
     • A creatinine increase of 1.5 to 1.9 times baseline
     • A creatinine increase of 2.0 to 2.9 times baseline
     • Urine output below 0.5 mL/kg per hour for 6 hours
     • The need to initiate renal replacement therapy

     Correct answer: The need to initiate renal replacement therapy

     The need to initiate renal replacement therapy is correct. The most severe stage of acute kidney injury is marked by the highest rise in creatinine (three-fold or more, or to 4.0 mg/dL) or by the requirement for dialysis, with initiation of renal replacement therapy denoting the top severity tier. A 1.5 to 1.9 fold rise and 6 hours of oliguria define the earliest stage, and a 2.0 to 2.9 fold rise defines an intermediate stage.

170. Chronic kidney disease is formally defined by abnormalities of kidney structure or function present for at least what minimum duration?
     • At least 2 weeks
     • At least 6 weeks
     • At least 3 months
     • At least 12 months

     Correct answer: At least 3 months

     At least 3 months is correct. Chronic kidney disease is defined as markers of kidney damage or a reduced glomerular filtration rate persisting for three months or longer, the duration that distinguishes a chronic process from acute kidney injury. Two weeks and six weeks are too short to meet the chronicity criterion, and requiring a full year would miss many cases that are already chronic.

171. A patient has an estimated glomerular filtration rate of 38 mL/min per 1.73 $\text{m}^2$ on two occasions three months apart. Which chronic kidney disease stage does this value represent?
     • Stage G2
     • Stage G3b
     • Stage G4
     • Stage G5

     Correct answer: Stage G3b

     Stage G3b is correct. A glomerular filtration rate of 30 to 44 mL/min per 1.73 $\text{m}^2$ falls in stage G3b under the standard glomerular filtration rate categories. Stage G2 corresponds to 60 to 89, stage G4 to 15 to 29, and stage G5 to below 15 or the need for dialysis, none of which match a value of 38.

172. Chronic kidney disease is staged not only by glomerular filtration rate but also by which additional measurement that independently predicts progression?
     • Serum sodium concentration
     • Total white blood cell count
     • Resting heart rate
     • Albuminuria category

     Correct answer: Albuminuria category

     Albuminuria category is correct. Modern chronic kidney disease classification combines the glomerular filtration rate category with the level of albuminuria, because increasing urinary albumin independently predicts faster progression and higher cardiovascular risk. Serum sodium, white blood cell count, and heart rate are not components of chronic kidney disease staging.

173. A patient with stage G4 chronic kidney disease has fatigue and a hemoglobin of 9.2 g/dL with normal iron stores. Which mechanism best explains the anemia of chronic kidney disease?
     • Reduced renal production of erythropoietin
     • Accelerated red cell production from uremia
     • Iron overload suppressing the marrow
     • Acute blood loss from the urinary tract

     Correct answer: Reduced renal production of erythropoietin

     Reduced renal production of erythropoietin is correct. The failing kidney makes less erythropoietin, the hormone that stimulates red cell production, leading to the normocytic anemia commonly seen in advanced chronic kidney disease. Uremia suppresses rather than accelerates erythropoiesis, the iron stores here are normal rather than overloaded, and there is no indication of acute urinary bleeding.

174. For a patient with chronic kidney disease and elevated phosphorus, which dietary or pharmacologic measure directly addresses the hyperphosphatemia?
     • Increased intake of dairy products
     • Routine intravenous calcium gluconate
     • A high-phosphorus diet to saturate absorption
     • Use of oral phosphate binders with meals

     Correct answer: Use of oral phosphate binders with meals

     Use of oral phosphate binders with meals is correct. Because the failing kidney cannot excrete the dietary phosphate load, oral phosphate binders taken with meals reduce gastrointestinal phosphate absorption and are combined with dietary phosphate restriction. Dairy products and a high-phosphorus diet add phosphate, and intravenous calcium is used for acute calcium or potassium problems rather than chronic phosphate control.

175. A patient with type 2 diabetes and chronic kidney disease has persistent albuminuria despite a maximized angiotensin receptor blocker. Which additional class of medication has been shown to slow progression of diabetic kidney disease?
     • A long-acting nonsteroidal anti-inflammatory drug
     • A sodium-glucose cotransporter-2 inhibitor
     • An intravenous aminoglycoside course
     • A high-dose loop diuretic for renoprotection

     Correct answer: A sodium-glucose cotransporter-2 inhibitor

     A sodium-glucose cotransporter-2 inhibitor is correct. These agents reduce intraglomerular pressure and albuminuria and have been shown to slow the progression of chronic kidney disease, particularly in diabetic kidney disease, when added to renin-angiotensin blockade. Nonsteroidal anti-inflammatory drugs and aminoglycosides are nephrotoxic, and loop diuretics manage volume without providing this disease-slowing benefit.

176. A patient with chronic kidney disease and a potassium of 6.6 mEq/L has a normal electrocardiogram but ongoing hyperkalemia. After acute measures, which approach helps remove potassium from the body rather than merely shifting it into cells?
     • Intravenous calcium gluconate
     • Nebulized albuterol
     • A potassium-binding resin or other gastrointestinal binder
     • Intravenous insulin with dextrose

     Correct answer: A potassium-binding resin or other gastrointestinal binder

     A potassium-binding resin or other gastrointestinal binder is correct. Gastrointestinal potassium binders, along with loop diuretics and dialysis, actually eliminate potassium from the body, whereas the other listed therapies only temporarily move potassium into cells or stabilize the heart. Calcium gluconate protects the myocardium, and both albuterol and insulin with dextrose shift potassium intracellularly without lowering total body stores.

177. In a patient with severe hyperkalemia and electrocardiographic changes, which medication is given first specifically to stabilize the cardiac membrane?
     • Oral sodium bicarbonate tablets
     • Intravenous calcium gluconate
     • Subcutaneous insulin alone
     • An oral potassium binder

     Correct answer: Intravenous calcium gluconate

     Intravenous calcium gluconate is correct. When hyperkalemia produces electrocardiographic changes, calcium is given first to rapidly stabilize the cardiac membrane and reduce the risk of fatal arrhythmia, even though it does not lower the potassium level. Insulin and binders act later to shift or remove potassium, and oral bicarbonate is not the immediate cardioprotective step.

178. A patient taking an ACE inhibitor and a potassium supplement is found to have a potassium of 6.2 mEq/L. Which action best addresses the most likely contributing cause?
     • Increase the potassium supplement dose
     • Add a second renin-angiotensin blocker
     • Begin a high-potassium oral diet
     • Stop the potassium supplement and reassess the ACE inhibitor

     Correct answer: Stop the potassium supplement and reassess the ACE inhibitor

     Stopping the potassium supplement and reassessing the ACE inhibitor is correct. ACE inhibitors reduce aldosterone-driven potassium excretion, and adding a potassium supplement compounds the risk, so the first step is to discontinue the supplement and review the renin-angiotensin agent. Increasing the supplement, adding a second blocking agent, or raising dietary potassium would all worsen the hyperkalemia.

179. A markedly elevated potassium value returns from the laboratory in a patient who appears well, has a normal electrocardiogram, and had a difficult blood draw with a tightly applied tourniquet. What is the most appropriate next step?
     • Immediately administer intravenous calcium
     • Repeat the potassium with a properly drawn specimen to exclude pseudohyperkalemia
     • Start emergent dialysis without further testing
     • Give a large oral potassium binder dose at once

     Correct answer: Repeat the potassium with a properly drawn specimen to exclude pseudohyperkalemia

     Repeating the potassium with a properly drawn specimen to exclude pseudohyperkalemia is correct. A high potassium in a well-appearing patient with a normal electrocardiogram and a traumatic, tourniquet-bound draw suggests pseudohyperkalemia from hemolysis, so confirmation with a clean sample is warranted before aggressive treatment. Empiric calcium, emergent dialysis, or a large binder dose would be premature without confirming a true elevation.

180. A 6-year-old presents with periorbital edema, frothy urine, and heavy proteinuria but no hematuria or hypertension, and the serum albumin is low. Which glomerular disease is the most likely cause of this nephrotic presentation in a child?
     • Post-streptococcal glomerulonephritis
     • Minimal change disease
     • IgA nephropathy
     • Anti-glomerular basement membrane disease

     Correct answer: Minimal change disease

     Minimal change disease is correct. The combination of heavy proteinuria, low albumin, and edema without hematuria or hypertension in a young child is the classic picture of minimal change disease, the most common cause of nephrotic syndrome in children. Post-streptococcal glomerulonephritis, IgA nephropathy, and anti-glomerular basement membrane disease all produce nephritic features such as hematuria rather than this pure nephrotic pattern.

181. A young man develops gross hematuria within one or two days of an upper respiratory infection, with red cells and red cell casts in the urine. Which glomerular disease classically presents with hematuria so soon after a mucosal infection?
     • Minimal change disease
     • Focal segmental glomerulosclerosis
     • IgA nephropathy
     • Membranous nephropathy

     Correct answer: IgA nephropathy

     IgA nephropathy is correct. Hematuria that appears within a day or two of an upper respiratory or mucosal infection, often called synpharyngitic hematuria, is the hallmark of IgA nephropathy, a nephritic process. Minimal change disease, focal segmental glomerulosclerosis, and membranous nephropathy are nephrotic patterns that do not feature this rapid post-infectious hematuria.

182. Which laboratory finding best distinguishes a nephritic urinary sediment from a nephrotic one?
     • Oval fat bodies and lipiduria
     • Proteinuria exceeding 3.5 grams per day
     • A markedly elevated serum cholesterol
     • Dysmorphic red cells and red cell casts

     Correct answer: Dysmorphic red cells and red cell casts

     Dysmorphic red cells and red cell casts is correct. A nephritic sediment is defined by glomerular hematuria with dysmorphic red cells and red cell casts reflecting inflammatory glomerular injury. Oval fat bodies and lipiduria, heavy proteinuria above 3.5 grams per day, and a high cholesterol are features of the nephrotic syndrome rather than the nephritic sediment.

183. An adult with HIV develops nephrotic-range proteinuria and progressive kidney failure, and a biopsy shows a collapsing pattern of glomerular scarring. Which glomerular disease is most strongly associated with this presentation?
     • Membranous nephropathy
     • Focal segmental glomerulosclerosis
     • Minimal change disease
     • Post-streptococcal glomerulonephritis

     Correct answer: Focal segmental glomerulosclerosis

     Focal segmental glomerulosclerosis is correct. A collapsing variant of focal segmental glomerulosclerosis is the classic cause of HIV-associated nephropathy, presenting with heavy nephrotic-range proteinuria and rapid decline in kidney function. Membranous nephropathy and minimal change disease cause nephrotic syndrome through different patterns, and post-streptococcal glomerulonephritis is a nephritic, post-infectious process rather than a collapsing sclerosis.

184. A physician assistant in the emergency department is treating an unconscious patient who arrived alone after a motor vehicle crash and requires immediate surgery to control internal bleeding. No family or surrogate is reachable, and there is no advance directive. Under which principle may the team proceed with the life-saving operation without obtaining the patient's signed consent?
     • The doctrine of implied consent in a genuine medical emergency when a reasonable person would want treatment
     • The therapeutic privilege to withhold information from the patient
     • The minimum necessary standard governing protected health information
     • The substituted-judgment standard applied by the surgeon alone

     Correct answer: The doctrine of implied consent in a genuine medical emergency when a reasonable person would want treatment

     Implied consent in an emergency is correct: when a patient is incapacitated, no surrogate is available, and delay would threaten life or limb, the law presumes the patient would consent to necessary care that a reasonable person would want. Therapeutic privilege concerns selectively withholding information from a patient who is receiving care, not authorizing treatment of an unconscious patient. The minimum necessary standard governs how much protected health information is shared, not whether emergency treatment may proceed. Substituted judgment requires a surrogate who can infer the patient's wishes, which does not describe a surgeon acting alone in an emergency.

185. A clinic discovers that an unencrypted laptop containing the protected health information of several hundred patients was stolen from an employee's car. Under HIPAA's Breach Notification Rule, what is the clinic generally obligated to do?
     • Notify the affected individuals and the Secretary of Health and Human Services of the breach
     • Take no action because the loss was caused by theft rather than the clinic
     • Notify only the patients who later report a problem with their information
     • Wait until the laptop is recovered before deciding whether notification is needed

     Correct answer: Notify the affected individuals and the Secretary of Health and Human Services of the breach

     Notifying affected individuals and HHS is correct: HIPAA's Breach Notification Rule requires covered entities to notify affected individuals and the Secretary of Health and Human Services after an impermissible acquisition of unsecured protected health information, with media notice also required for larger breaches. The breach being caused by theft does not relieve the clinic of its notification duties. Notification cannot be limited to patients who happen to report a problem, since all affected individuals must be informed. Delaying notification until the device is recovered would violate the rule's required timeframes for reporting.

186. A 16-year-old presents alone seeking testing and treatment for a suspected sexually transmitted infection and does not want their parents involved. In most jurisdictions, why may a minor be permitted to consent to this specific care without parental involvement?
     • Because any minor may consent to all medical care once they reach age 16
     • Because parental consent is never required for any treatment of a minor
     • Because the clinic may bill the parents, which substitutes for their consent
     • Because minor-consent statutes commonly allow confidential consent for sensitive services such as sexually transmitted infection care

     Correct answer: Because minor-consent statutes commonly allow confidential consent for sensitive services such as sexually transmitted infection care

     Minor-consent statutes for sensitive services is correct: many states specifically permit minors to consent to confidential care for sexually transmitted infections, reproductive health, and similar services to encourage care-seeking, even though minors generally cannot consent to most treatment. It is not true that any minor may consent to all care at 16, since these statutes are limited to defined sensitive categories. Parental consent is generally required for most minor care outside these specific exceptions, so the claim that it is never required is wrong. Billing the parents does not constitute consent and does not address the legal authority to treat.

187. During a psychiatric visit, a patient with capacity makes a specific, credible threat to seriously harm a named individual. Many jurisdictions recognize a legal duty in this situation that can override ordinary confidentiality. What does this duty most directly require the clinician to consider?
     • Disclosing the patient's entire medical record to the public
     • Maintaining absolute confidentiality regardless of the threat
     • Transferring all decision-making to the patient's family
     • Taking reasonable steps to protect the identifiable potential victim, which may include warning or notifying authorities

     Correct answer: Taking reasonable steps to protect the identifiable potential victim, which may include warning or notifying authorities

     Taking reasonable steps to protect the identifiable victim is correct: when a patient poses a serious, credible threat to an identifiable person, many jurisdictions impose a duty that permits or requires breaking confidentiality to warn the potential victim or notify law enforcement. Disclosing the entire record to the public goes far beyond what the duty contemplates and is not appropriate. Maintaining absolute confidentiality ignores the recognized exception that protects third parties from serious harm. Transferring decision-making to the family does not address the clinician's own legal obligation to act to protect the threatened person.

188. A patient reviews their record and believes a documented detail about their family history is factually inaccurate. The patient submits a written request to have the record changed. Under HIPAA, which right is the patient exercising?
     • The right to revoke a previously signed authorization
     • The right to opt out of the facility directory
     • The right to request an amendment of their protected health information
     • The right to receive a notice of privacy practices

     Correct answer: The right to request an amendment of their protected health information

     The right to request an amendment is correct: HIPAA gives individuals the right to ask a covered entity to amend protected health information they believe is inaccurate or incomplete, and the entity must respond, though it may deny the request under defined circumstances. Revoking an authorization concerns withdrawing prior permission to disclose information, not correcting the record's content. Opting out of the facility directory controls whether the patient is listed as present in a facility, not the accuracy of clinical entries. Receiving a notice of privacy practices informs the patient of how information is handled but is not the mechanism for correcting an entry.

189. A physician assistant recognizes that they tend to spend less time counseling patients from a particular demographic group, an unconscious tendency they had not previously noticed. Within a diversity, equity, and inclusion framework, what is this phenomenon called, and what is an appropriate response?
     • Implicit bias, which can be mitigated through self-awareness, training, and standardized care processes
     • Explicit discrimination that requires no further reflection because it was unintentional
     • A normal variation that has no measurable effect on patient outcomes
     • A billing inefficiency to be corrected through scheduling changes

     Correct answer: Implicit bias, which can be mitigated through self-awareness, training, and standardized care processes

     Implicit bias with mitigation is correct: unconscious attitudes that influence behavior toward groups of patients are termed implicit bias, and recognized responses include building self-awareness, bias training, and standardizing care processes to reduce disparate treatment. Calling it explicit discrimination misnames the unconscious nature of the tendency and wrongly implies no reflection is warranted. Treating it as a harmless variation contradicts evidence that implicit bias contributes to disparities in care. Framing it as a billing inefficiency mischaracterizes an equity issue about quality and fairness of care.

190. A patient requests a copy of their psychotherapy notes that a behavioral health provider kept separate from the rest of the medical record. Under HIPAA, how are these psychotherapy notes generally treated compared with the rest of the record?
     • They receive less protection than ordinary records and may be shared freely
     • They are entirely exempt from HIPAA and have no protection at all
     • They must always be released to any family member who asks
     • They receive special protection and generally require specific authorization for most disclosures

     Correct answer: They receive special protection and generally require specific authorization for most disclosures

     Special protection requiring specific authorization is correct: HIPAA singles out psychotherapy notes kept separate from the rest of the record for heightened protection, generally requiring a specific authorization before most uses or disclosures, even those that would otherwise be permitted for treatment, payment, or operations. The notion that they receive less protection and may be shared freely is the opposite of the rule. They are not exempt from HIPAA; rather, they are more strictly safeguarded. They are not subject to automatic release to any family member, which would contradict their elevated protection.

191. A physician assistant suspects, based on the examination and history, that a young child's injuries are the result of physical abuse. The parent asks the clinician not to tell anyone. What is the clinician's legal obligation in most jurisdictions?
     • Honor the parent's request and keep the suspicion confidential
     • Wait for definitive proof of abuse before involving anyone
     • Report the reasonable suspicion of child abuse to the appropriate child protective authority
     • Discharge the child and document only that the parent declined further evaluation

     Correct answer: Report the reasonable suspicion of child abuse to the appropriate child protective authority

     Reporting the reasonable suspicion is correct: clinicians are mandated reporters who must notify the appropriate child protective authority when they have a reasonable suspicion of child abuse, and this legal duty overrides a parent's request for confidentiality. Honoring the parent's request would violate the mandatory reporting obligation. The standard for reporting is reasonable suspicion, not definitive proof, so waiting for certainty is incorrect. Discharging the child while documenting only parental refusal fails the duty to report and abandons a potentially endangered child.

192. A patient with limited English proficiency is scheduled to consent to a surgical procedure, and the clinic plans to rely on the patient's teenage relative to translate the risks and alternatives. Within an equity-focused, ethically sound consent process, why is using a professional interpreter preferred?
     • Because professional interpreters reduce the clinic's documentation burden
     • Because relatives are legally prohibited from being present during any consent discussion
     • Because accurate interpretation of risks and alternatives is essential for the consent to be truly informed
     • Because using a relative would require the patient to pay an additional fee

     Correct answer: Because accurate interpretation of risks and alternatives is essential for the consent to be truly informed

     Ensuring accurate interpretation is correct: valid informed consent depends on the patient genuinely understanding the risks, benefits, and alternatives, and a trained professional interpreter provides the accuracy and impartiality that an untrained family member, especially a child, cannot reliably offer. Reducing documentation burden is not the rationale and is unrelated to the integrity of consent. There is no blanket legal prohibition on relatives being present, so that justification is inaccurate. The preference for a professional interpreter is grounded in comprehension and equity, not in avoiding a fee for the patient.

193. A physician assistant must decide whether to start a medication that offers modest benefit but carries a meaningful risk of serious harm for this particular patient. Weighing the obligation to avoid causing harm to the patient most directly invokes which ethical principle?
     • Veracity
     • Nonmaleficence
     • Distributive justice
     • Confidentiality

     Correct answer: Nonmaleficence

     Nonmaleficence is correct: the duty to avoid inflicting harm, captured in the principle of nonmaleficence, is the consideration at stake when a clinician weighs a treatment's potential to cause serious harm against its limited benefit. Veracity concerns truthfulness in communication, not the avoidance of harm in a treatment decision. Distributive justice addresses the fair allocation of resources across patients, not the risk-benefit balance for an individual. Confidentiality governs the protection of patient information and does not bear on the harm-versus-benefit judgment of a therapy.

194. A health system begins systematically collecting patients' self-reported race, ethnicity, and preferred language in a standardized way. Within a diversity, equity, and inclusion framework, what is the primary purpose of gathering this data?
     • To allow the system to charge different prices to different groups
     • To identify and address disparities in access, quality, and outcomes across populations
     • To restrict certain services to specific demographic groups
     • To replace clinical judgment with demographic profiling

     Correct answer: To identify and address disparities in access, quality, and outcomes across populations

     Identifying and addressing disparities is correct: collecting standardized race, ethnicity, and language data lets a health system measure differences in access, quality, and outcomes across groups so it can target improvements, which is the core aim of equity work. Charging different prices to different groups is not the purpose and would itself be inequitable. Restricting services to particular groups contradicts the inclusive intent of the data collection. Replacing clinical judgment with demographic profiling misuses the data and runs counter to the goal of individualized, equitable care.

195. A capacitated patient with a terminal illness decides to decline further disease-directed treatment in favor of comfort-focused care, fully understanding that this choice will likely shorten survival. The clinician disagrees with the decision but finds the patient's reasoning clear and consistent. What is the most ethically appropriate response?
     • Override the decision because the clinician believes continued treatment is better
     • Respect the capacitated patient's informed decision to decline treatment and provide supportive care
     • Require a court order before the patient may decline disease-directed treatment
     • Transfer the decision to the patient's relatives because the choice is serious

     Correct answer: Respect the capacitated patient's informed decision to decline treatment and provide supportive care

     Respecting the informed decision is correct: a capacitated, well-informed patient has the right to decline treatment, including disease-directed therapy, even when the clinician disagrees, and the appropriate response is to honor that choice and provide comfort-focused care. Overriding the decision because the clinician prefers continued treatment violates the patient's autonomy. A court order is not required for a capacitated patient to refuse treatment, so demanding one is inappropriate. Transferring the decision to relatives disregards that the capacitated patient retains authority over their own care.

196. A 67-year-old man with a 50 pack-year smoking history reports chronic productive cough and dyspnea on exertion. Spirometry shows a post-bronchodilator FEV1/FVC ratio of 0.62. Which finding establishes the diagnosis of chronic obstructive pulmonary disease?
     • The reduced post-bronchodilator FEV1/FVC ratio below 0.70
     • A bronchodilator response increasing FEV1 by 15 percent
     • The smoking history alone
     • A total lung capacity below predicted

     Correct answer: The reduced post-bronchodilator FEV1/FVC ratio below 0.70

     The reduced post-bronchodilator FEV1/FVC ratio below 0.70 is what establishes COPD, because persistent airflow obstruction that does not normalize after a bronchodilator defines the disease spirometrically. A large bronchodilator response suggests asthma instead, smoking history is a risk factor but not diagnostic, and a reduced total lung capacity points toward restriction rather than obstruction.

197. A 70-year-old woman with COPD develops an acute exacerbation with increased sputum purulence, increased sputum volume, and worsening dyspnea. Which therapy directly addresses the bacterial component suggested by these cardinal features?
     • Inhaled corticosteroid monotherapy
     • A short course of oral antibiotics
     • Long-term oxygen therapy
     • Pulmonary rehabilitation

     Correct answer: A short course of oral antibiotics

     A short course of oral antibiotics is indicated because the presence of all three Anthonisen cardinal symptoms, particularly increased sputum purulence, predicts bacterial infection that benefits from antibiotics during a COPD exacerbation. Inhaled corticosteroid monotherapy is not an exacerbation rescue treatment, long-term oxygen is a chronic survival intervention rather than acute infection treatment, and pulmonary rehabilitation is a stable-phase program.

198. A patient with severe COPD has a chest radiograph showing flattened diaphragms, increased retrosternal air space, and hyperlucent lung fields. Which pathophysiologic process do these radiographic features most directly reflect?
     • Pulmonary fibrosis
     • Lobar consolidation
     • Air trapping and hyperinflation
     • Pleural thickening

     Correct answer: Air trapping and hyperinflation

     Air trapping and hyperinflation is correct because flattened diaphragms, an enlarged retrosternal air space, and hyperlucent lungs result from gas trapped behind obstructed and collapsed small airways in COPD. Fibrosis produces reticular opacities and volume loss, consolidation produces airspace opacification, and pleural thickening appears as peripheral density rather than hyperlucency.

199. A clinician is counseling a 58-year-old smoker with moderate COPD about which single intervention most slows the decline in lung function over time. Which measure should be emphasized?
     • Daily inhaled corticosteroids
     • Routine prophylactic antibiotics
     • Chronic theophylline
     • Smoking cessation

     Correct answer: Smoking cessation

     Smoking cessation is correct because stopping smoking is the only intervention proven to slow the accelerated rate of FEV1 decline in COPD and improve survival. Inhaled corticosteroids and theophylline relieve symptoms or reduce exacerbations but do not chiefly alter the long-term rate of lung function loss, and routine prophylactic antibiotics are not a standard disease-modifying therapy.

200. A 65-year-old man with COPD has not been hospitalized and has an mMRC dyspnea score of 1 with no exacerbations in the past year. According to current GOLD group classification, which initial pharmacologic approach is most appropriate?
     • A single long-acting bronchodilator
     • Triple inhaled therapy with a long-acting muscarinic antagonist, long-acting beta-2 agonist, and inhaled corticosteroid
     • Chronic oral corticosteroids
     • Roflumilast

     Correct answer: A single long-acting bronchodilator

     A single long-acting bronchodilator is correct because a patient with low symptom burden and no exacerbation history falls into GOLD group A, for whom a single bronchodilator is the recommended starting therapy. Triple therapy is reserved for patients with high symptoms and exacerbations, chronic oral corticosteroids are avoided, and roflumilast targets the chronic bronchitis exacerbation phenotype.

201. A 60-year-old woman with COPD reports increased symptoms each winter. Which vaccination is most important to recommend annually to reduce her risk of an infectious exacerbation?
     • Tetanus vaccine
     • Influenza vaccine
     • Hepatitis A vaccine
     • Human papillomavirus vaccine

     Correct answer: Influenza vaccine

     The influenza vaccine is correct because annual influenza vaccination reduces serious illness and exacerbations in patients with COPD, who are vulnerable to respiratory infections. Tetanus, hepatitis A, and human papillomavirus vaccines protect against unrelated conditions and do not specifically lower the risk of an infectious COPD exacerbation.

202. A patient with stable COPD asks how supplemental oxygen helps him when his resting arterial oxygen pressure is 50 mm Hg. Which long-term benefit is the principal evidence-based reason to prescribe continuous oxygen at this level?
     • It cures the underlying airflow obstruction
     • It reverses emphysematous destruction
     • It improves survival in chronically hypoxemic patients
     • It eliminates the need for inhalers

     Correct answer: It improves survival in chronically hypoxemic patients

     Improved survival in chronically hypoxemic patients is correct because continuous oxygen therapy for severe resting hypoxemia is one of few interventions shown to prolong life in COPD. Oxygen does not cure airflow obstruction, reverse emphysema, or replace inhaled bronchodilators and anti-inflammatory therapy.

203. A 27-year-old patient with asthma reports daily symptoms and nighttime awakenings more than once weekly, with an FEV1 that is 75 percent of predicted between flares. How is this asthma severity best classified?
     • Intermittent
     • Mild persistent
     • Severe persistent
     • Moderate persistent

     Correct answer: Moderate persistent

     Moderate persistent is correct because daily symptoms, nighttime awakenings more than once weekly, and an FEV1 between 60 and 80 percent of predicted define the moderate persistent category. Intermittent and mild persistent involve less frequent symptoms with normal or near-normal lung function, while severe persistent involves continuous symptoms and an FEV1 below 60 percent of predicted.

204. A 22-year-old runner reports cough, chest tightness, and wheeze occurring only during cold-weather exercise, with normal baseline spirometry. Which pretreatment is most appropriate to prevent these exercise-induced symptoms?
     • A short-acting beta-2 agonist before activity
     • A daily oral antihistamine
     • Chronic oral corticosteroids
     • A bedtime long-acting muscarinic antagonist

     Correct answer: A short-acting beta-2 agonist before activity

     A short-acting beta-2 agonist taken before activity is correct because inhaling it shortly before exercise prevents exercise-induced bronchoconstriction in patients whose symptoms occur only with exertion. Oral antihistamines do not prevent bronchospasm, chronic oral corticosteroids are excessive for isolated exercise symptoms, and a bedtime muscarinic antagonist does not target the timing of exercise-triggered narrowing.

205. A patient with asthma demonstrates an FEV1 that increases by 14 percent and 250 mL after inhaling a bronchodilator during spirometry. How should this result be interpreted in the diagnostic workup?
     • It confirms restrictive lung disease
     • It demonstrates significant reversible airflow obstruction supporting asthma
     • It rules out asthma entirely
     • It indicates fixed obstruction typical of COPD

     Correct answer: It demonstrates significant reversible airflow obstruction supporting asthma

     Demonstrating significant reversible airflow obstruction is correct because an FEV1 improvement of at least 12 percent and 200 mL after a bronchodilator indicates the reversibility characteristic of asthma. It does not confirm restriction, does not exclude asthma, and the presence of meaningful reversibility argues against the fixed obstruction typical of COPD.

206. A 30-year-old woman with asthma well controlled on a daily inhaled corticosteroid asks how this controller medication works to reduce her flares. Which mechanism best describes its therapeutic action?
     • It causes immediate bronchodilation within seconds
     • It thins respiratory secretions directly
     • It reduces airway inflammation over time
     • It blocks histamine receptors in the airway

     Correct answer: It reduces airway inflammation over time

     Reducing airway inflammation over time is correct because inhaled corticosteroids suppress the chronic eosinophilic airway inflammation underlying asthma, lowering symptom frequency and exacerbations with regular use. They do not provide rapid bronchodilation, are not mucolytics, and do not work primarily by blocking histamine receptors.

207. A 35-year-old man whose asthma is uncontrolled on a low-dose inhaled corticosteroid alone is reassessed. Which step-up adjustment is generally preferred to improve control while limiting corticosteroid dose?
     • Beginning chronic systemic corticosteroids
     • Switching to a short-acting beta-2 agonist alone
     • Stopping all controller therapy
     • Adding a long-acting beta-2 agonist to the inhaled corticosteroid

     Correct answer: Adding a long-acting beta-2 agonist to the inhaled corticosteroid

     Adding a long-acting beta-2 agonist to the inhaled corticosteroid is correct because combination controller therapy improves control in persistent asthma inadequately managed on a low-dose inhaled corticosteroid alone. A short-acting beta-2 agonist alone provides no anti-inflammatory benefit, stopping controllers worsens disease, and chronic systemic corticosteroids are a last resort rather than a routine step-up.

208. A 19-year-old presents to the emergency department with an acute asthma exacerbation and oxygen saturation of 93 percent. Which medication class provides the most rapid relief of bronchospasm as first-line acute therapy?
     • An inhaled short-acting beta-2 agonist
     • An inhaled corticosteroid
     • An oral leukotriene receptor antagonist
     • An anti-immunoglobulin E biologic

     Correct answer: An inhaled short-acting beta-2 agonist

     An inhaled short-acting beta-2 agonist is correct because it produces prompt bronchodilation and is the first-line rescue therapy for acute asthma exacerbations. An inhaled corticosteroid acts too slowly for acute relief, a leukotriene antagonist is a controller, and an anti-immunoglobulin E biologic is a long-term add-on for severe allergic asthma rather than an acute rescue agent.

209. A 70-year-old man hospitalized for community-acquired pneumonia is confused, has a blood urea nitrogen of 25 mg/dL, a respiratory rate of 32 breaths per minute, and a blood pressure of 88/56 mm Hg. Approximately how many CURB-65 points has he accumulated from these findings?
     • One point
     • Five points
     • Three points
     • Two points

     Correct answer: Five points

     Five points is correct because confusion, blood urea nitrogen above 19 mg/dL, respiratory rate of 30 or more, systolic blood pressure below 90 mm Hg, and age 65 or older each contribute one point, and this patient meets all five criteria. Fewer points would underestimate his severity, and a CURB-65 of 5 indicates very high mortality risk warranting intensive evaluation.

210. An otherwise healthy 34-year-old woman with no comorbidities is diagnosed with mild outpatient community-acquired pneumonia and no recent antibiotic use. Which empiric oral regimen is an appropriate first-line choice in this low-risk patient?
     • A high-dose intravenous antipseudomonal beta-lactam
     • Oral vancomycin
     • Amoxicillin or doxycycline
     • An antifungal agent

     Correct answer: Amoxicillin or doxycycline

     Amoxicillin or doxycycline is correct because a healthy outpatient without comorbidities or recent antibiotics can be treated empirically with a first-line agent such as amoxicillin or doxycycline. An intravenous antipseudomonal beta-lactam is reserved for severe or high-risk disease, oral vancomycin treats Clostridioides difficile rather than pneumonia, and an antifungal does not cover typical bacterial pneumonia.

211. A previously well 40-year-old man with community-acquired pneumonia improves clinically after starting antibiotics, becoming afebrile with resolving cough by day three. How long is a typical minimum course of antibiotic therapy for uncomplicated community-acquired pneumonia in a responding patient?
     • Until the chest radiograph is fully normal
     • Exactly 24 hours
     • A minimum of six weeks
     • At least five days, guided by clinical stability

     Correct answer: At least five days, guided by clinical stability

     At least five days guided by clinical stability is correct because uncomplicated community-acquired pneumonia is typically treated for a minimum of about five days, continued until the patient is afebrile and clinically stable. A 24-hour course is too short, six weeks is excessive and reserved for complicated infections, and radiographic clearing lags well behind clinical recovery and does not dictate antibiotic duration.

212. A 55-year-old man with community-acquired pneumonia and a CURB-65 score of 0 is being considered for disposition. Beyond the score, which additional factor would most appropriately prompt admission rather than outpatient treatment?
     • Inability to maintain oral intake with hypoxemia on room air
     • A mild dry cough
     • A normal mental status
     • A single low-grade fever

     Correct answer: Inability to maintain oral intake with hypoxemia on room air

     Inability to maintain oral intake with hypoxemia on room air is correct because clinical judgment beyond the CURB-65 score, including hypoxemia and inability to tolerate oral medications, can justify admission even when the score is low. A mild cough, normal mental status, and an isolated low-grade fever do not by themselves mandate inpatient care.

213. A 48-year-old man presents with community-acquired pneumonia, and the clinician considers obtaining a chest radiograph. What is the primary role of chest radiography in the diagnosis of community-acquired pneumonia?
     • To grade airflow obstruction severity
     • To confirm a pulmonary infiltrate consistent with pneumonia
     • To measure the apnea-hypopnea index
     • To establish the presence of reversible bronchospasm

     Correct answer: To confirm a pulmonary infiltrate consistent with pneumonia

     Confirming a pulmonary infiltrate consistent with pneumonia is correct because demonstrating a new infiltrate on chest radiography supports the clinical diagnosis of pneumonia. Radiography does not grade airflow obstruction, does not measure the apnea-hypopnea index, and does not establish reversible bronchospasm, which require spirometry or sleep testing.

214. A 58-year-old woman with active cancer presents with sudden dyspnea and tachycardia. Using the Wells criteria for pulmonary embolism, which element of her presentation carries one of the highest point values toward the score?
     • A history of prior asthma
     • A normal heart rate
     • Clinical signs of deep venous thrombosis
     • Absence of hemoptysis

     Correct answer: Clinical signs of deep venous thrombosis

     Clinical signs of deep venous thrombosis is correct because objective leg swelling and tenderness contribute one of the largest point allocations in the Wells criteria, reflecting the strong link between venous thrombosis and pulmonary embolism. A history of asthma is not a Wells element, a normal heart rate adds no points, and the absence of hemoptysis does not raise the score.

215. A stable 45-year-old patient with low pretest probability for pulmonary embolism has a negative high-sensitivity D-dimer. What is the most appropriate next step?
     • Proceed directly to computed tomography pulmonary angiography
     • Start empiric therapeutic anticoagulation
     • Place an inferior vena cava filter
     • Reasonably exclude pulmonary embolism without further imaging

     Correct answer: Reasonably exclude pulmonary embolism without further imaging

     Reasonably excluding pulmonary embolism without further imaging is correct because a negative high-sensitivity D-dimer in a patient with low pretest probability has a high negative predictive value, safely ruling out the diagnosis. Proceeding to angiography or starting anticoagulation is unnecessary, and a filter is not indicated when embolism has been excluded.

216. A 62-year-old man presents with acute pulmonary embolism and is hypotensive with a systolic blood pressure of 80 mm Hg despite fluids. Which therapy is most appropriate for this hemodynamically unstable, massive embolism?
     • Systemic thrombolytic therapy
     • Observation with serial D-dimers
     • Oral aspirin alone
     • Inhaled bronchodilators

     Correct answer: Systemic thrombolytic therapy

     Systemic thrombolytic therapy is correct because a massive pulmonary embolism with persistent hypotension is life-threatening and, absent contraindications, warrants thrombolysis to rapidly restore pulmonary perfusion. Observation, aspirin alone, and inhaled bronchodilators are inadequate for hemodynamically unstable embolism.

217. A 50-year-old woman is diagnosed with a first unprovoked pulmonary embolism with no major bleeding risk. What is the recommended minimum duration of anticoagulation for this event?
     • About 1 week
     • At least 3 months
     • Exactly 14 days
     • No anticoagulation is needed

     Correct answer: At least 3 months

     At least 3 months is correct because acute pulmonary embolism is treated with a minimum of three months of anticoagulation, with extended therapy considered for unprovoked or recurrent events. A one-week or two-week course is too short to prevent recurrence, and omitting anticoagulation entirely would leave a confirmed embolism untreated.

218. A 60-year-old hospitalized patient with limited mobility after major surgery has no contraindication to prophylaxis. Which measure most directly reduces the risk of developing a pulmonary embolism during the admission?
     • Routine antibiotics
     • Daily incentive spirometry alone
     • Pharmacologic venous thromboembolism prophylaxis
     • Strict bed rest without other measures

     Correct answer: Pharmacologic venous thromboembolism prophylaxis

     Pharmacologic venous thromboembolism prophylaxis is correct because prophylactic anticoagulation in immobilized postsurgical patients reduces the formation of deep venous thrombi that can embolize to the lungs. Incentive spirometry helps prevent atelectasis but not clot, antibiotics do not prevent thrombosis, and strict bed rest actually increases venous stasis and clot risk.

219. A 47-year-old woman with a suspected pulmonary embolism and normal renal function and no contrast allergy undergoes imaging. Which study is the preferred first-line diagnostic test to confirm pulmonary embolism?
     • Plain chest radiograph
     • Ventilation-perfusion scan as the routine first choice
     • Transthoracic echocardiography
     • Computed tomography pulmonary angiography

     Correct answer: Computed tomography pulmonary angiography

     Computed tomography pulmonary angiography is correct because it is the preferred first-line confirmatory imaging study for pulmonary embolism in patients without contraindications, directly visualizing intraluminal clot. A plain chest radiograph cannot confirm embolism, echocardiography is supportive but not definitive, and a ventilation-perfusion scan is reserved for when angiography cannot be used.

220. A clinician applies Light's criteria to pleural fluid analysis. Which single criterion, if met, classifies the fluid as exudative when comparing pleural and serum values?
     • Pleural fluid protein to serum protein ratio greater than 0.5
     • Pleural fluid glucose equal to serum glucose
     • Pleural fluid pH of 7.45
     • Clear straw-colored appearance

     Correct answer: Pleural fluid protein to serum protein ratio greater than 0.5

     A pleural fluid protein to serum protein ratio greater than 0.5 is correct because meeting any one of Light's criteria, including this protein ratio, classifies the effusion as an exudate. Glucose equal to serum, a normal pH, and a clear appearance do not satisfy Light's criteria and are more consistent with a transudate.

221. A 55-year-old man with a unilateral pleural effusion of uncertain cause is evaluated. Which procedure is most appropriate to obtain fluid for analysis and determine whether the effusion is a transudate or exudate?
     • Bronchoscopy
     • Diagnostic thoracentesis
     • Spirometry
     • Cardiac catheterization

     Correct answer: Diagnostic thoracentesis

     Diagnostic thoracentesis is correct because sampling pleural fluid with a needle allows laboratory analysis and application of Light's criteria to classify the effusion and direct further workup. Bronchoscopy evaluates the airways, spirometry assesses airflow, and cardiac catheterization studies the heart and coronary arteries rather than the pleural space.

222. Pleural fluid from a patient is analyzed and shows lymphocyte predominance with a markedly elevated adenosine deaminase level. Which diagnosis does this profile most strongly suggest?
     • Heart failure
     • Hepatic hydrothorax
     • Tuberculous pleural effusion
     • Nephrotic syndrome

     Correct answer: Tuberculous pleural effusion

     Tuberculous pleural effusion is correct because a lymphocyte-predominant exudate with a high adenosine deaminase level is characteristic of pleural tuberculosis. Heart failure, hepatic hydrothorax, and nephrotic syndrome produce transudative effusions without elevated adenosine deaminase.

223. A patient with a parapneumonic pleural effusion has fluid analysis showing a pH of 7.10 and a low glucose. Which management decision do these findings most strongly support?
     • Continued observation alone
     • Repeat imaging in three months
     • Outpatient oral diuretics
     • Chest tube drainage of the pleural space

     Correct answer: Chest tube drainage of the pleural space

     Chest tube drainage is correct because a parapneumonic effusion with a low pH and low glucose indicates a complicated effusion or empyema that requires drainage in addition to antibiotics. Observation, diuretics, and delayed repeat imaging would allow an infected, loculating effusion to progress.

224. A 16-year-old boy with a positive family history is found to have a small effusion that, on thoracentesis, yields fluid meeting an exudative protein criterion. Which initial laboratory comparison underlies the application of Light's criteria?
     • Comparing pleural and serum protein and lactate dehydrogenase levels
     • Comparing pleural and serum sodium levels
     • Comparing arterial and venous oxygen levels
     • Comparing inspiratory and expiratory peak flow

     Correct answer: Comparing pleural and serum protein and lactate dehydrogenase levels

     Comparing pleural and serum protein and lactate dehydrogenase levels is correct because Light's criteria classify an effusion as exudative using the pleural-to-serum protein ratio, the pleural-to-serum lactate dehydrogenase ratio, and the absolute pleural lactate dehydrogenase. Sodium comparisons, blood oxygen gradients, and peak flow measurements are not part of Light's criteria.

225. An 18-year-old tall, thin man develops sudden unilateral pleuritic chest pain and dyspnea at rest with no preceding trauma. Examination reveals decreased breath sounds and hyperresonance on the affected side. Which diagnosis is most likely?
     • Lobar pneumonia
     • Primary spontaneous pneumothorax
     • Pulmonary edema
     • Pleural effusion

     Correct answer: Primary spontaneous pneumothorax

     Primary spontaneous pneumothorax is correct because sudden pleuritic chest pain with dyspnea, decreased breath sounds, and hyperresonance in a tall, thin young man without lung disease is the classic presentation. Pneumonia produces crackles and dullness, pulmonary edema produces bilateral crackles, and a pleural effusion produces dullness rather than hyperresonance.

226. A trauma patient develops sudden hypotension, distended neck veins, and tracheal deviation away from a hyperresonant hemithorax with absent breath sounds. Which life-threatening diagnosis must be treated immediately, even before imaging?
     • Simple pleural effusion
     • Asthma exacerbation
     • Tension pneumothorax
     • Stable rib fracture

     Correct answer: Tension pneumothorax

     Tension pneumothorax is correct because hypotension, distended neck veins, tracheal deviation away from the affected side, and absent breath sounds reflect rising intrapleural pressure compressing the mediastinum and great vessels, requiring immediate decompression. A simple effusion, an asthma exacerbation, and a stable rib fracture do not produce this rapidly fatal physiology.

227. A 25-year-old man treated for a first primary spontaneous pneumothorax has a small residual pneumothorax and is otherwise stable and asymptomatic. Which conservative management option is appropriate for a small, stable primary pneumothorax?
     • Immediate pleurodesis
     • Emergency thoracotomy
     • Therapeutic anticoagulation
     • Observation with supplemental oxygen and follow-up imaging

     Correct answer: Observation with supplemental oxygen and follow-up imaging

     Observation with supplemental oxygen and follow-up imaging is correct because a small, stable primary spontaneous pneumothorax in an asymptomatic patient can be managed conservatively, with oxygen accelerating reabsorption of pleural air. Pleurodesis and thoracotomy are reserved for recurrent or persistent cases, and anticoagulation has no role in treating a pneumothorax.

228. A patient with a recurrent ipsilateral spontaneous pneumothorax has had a second event on the same side. Which intervention is most appropriate to prevent further recurrences?
     • Pleurodesis or surgical bleb resection
     • Long-term oral corticosteroids
     • Chronic bronchodilator therapy
     • Repeat needle aspiration each time without further measures

     Correct answer: Pleurodesis or surgical bleb resection

     Pleurodesis or surgical bleb resection is correct because recurrent spontaneous pneumothorax on the same side warrants a definitive procedure to obliterate the pleural space or remove the culprit blebs and reduce recurrence. Oral corticosteroids and bronchodilators do not prevent recurrence, and repeated aspiration alone does not address the underlying predisposition.

229. A clinician is taught that the safest landmark for placing a chest tube to manage a pneumothorax is within the so-called triangle of safety. Which anatomic region defines this area?
     • Over the scapula posteriorly
     • The region bordered by the lateral pectoralis major, the lateral latissimus dorsi, and a line at the nipple level in the axilla
     • Directly over the manubrium
     • Just above the clavicle

     Correct answer: The region bordered by the lateral pectoralis major, the lateral latissimus dorsi, and a line at the nipple level in the axilla

     The region bordered by the lateral edge of the pectoralis major, the lateral edge of the latissimus dorsi, and a horizontal line at the nipple level is correct because this axillary triangle of safety minimizes the risk of injuring vital structures during chest tube insertion. Placement over the scapula, the manubrium, or above the clavicle risks vascular, mediastinal, or neurovascular injury.

230. A 35-year-old recent immigrant from a high-burden country has a positive interferon-gamma release assay, no symptoms, and a normal chest radiograph. How is this finding best classified?
     • Active pulmonary tuberculosis requiring four-drug therapy
     • Sarcoidosis
     • Latent tuberculosis infection
     • A false test that requires no further action

     Correct answer: Latent tuberculosis infection

     Latent tuberculosis infection is correct because a positive interferon-gamma release assay with no symptoms and a normal chest radiograph indicates immune sensitization without active disease. Active tuberculosis would show symptoms or radiographic findings, sarcoidosis is a separate granulomatous disease, and dismissing a positive test would miss an opportunity for preventive treatment.

231. A 42-year-old asymptomatic patient is diagnosed with latent tuberculosis infection and has normal liver function. Which treatment approach is appropriate to prevent progression to active disease?
     • A standard four-drug active-disease regimen for six months
     • Lifelong daily ethambutol
     • No treatment because latent infection cannot progress
     • A shorter rifamycin-based or isoniazid-based regimen for latent infection

     Correct answer: A shorter rifamycin-based or isoniazid-based regimen for latent infection

     A shorter rifamycin-based or isoniazid-based regimen is correct because latent tuberculosis infection is treated with a preventive single- or two-drug course, such as rifampin or isoniazid-containing regimens, to reduce the chance of reactivation. A full four-drug regimen is for active disease, latent infection can reactivate so observation alone is inadequate, and lifelong ethambutol is not a latent treatment.

232. A patient on isoniazid, rifampin, pyrazinamide, and ethambutol for active tuberculosis develops new nausea, right upper quadrant pain, and markedly elevated transaminases. Which adverse effect of antituberculous therapy is most likely?
     • Drug-induced hepatotoxicity
     • Acute renal failure
     • Pancreatitis
     • Hemolytic anemia

     Correct answer: Drug-induced hepatotoxicity

     Drug-induced hepatotoxicity is correct because isoniazid, rifampin, and pyrazinamide can each cause liver injury, and new nausea, right upper quadrant pain, and rising transaminases indicate hepatotoxicity that requires holding the offending drugs. The clinical picture and the known toxicity profile of these agents make renal failure, pancreatitis, and hemolysis far less likely explanations.

233. A hospitalized patient with suspected active pulmonary tuberculosis is awaiting confirmatory testing. Which infection-control measure is most important to prevent transmission to others?
     • Standard precautions only
     • Airborne isolation in a negative-pressure room
     • Contact precautions with gowns and gloves
     • Droplet precautions with a surgical mask only

     Correct answer: Airborne isolation in a negative-pressure room

     Airborne isolation in a negative-pressure room is correct because Mycobacterium tuberculosis spreads via airborne droplet nuclei, requiring a negative-pressure room and respiratory protection such as a fit-tested respirator. Standard, contact, and droplet precautions alone do not adequately contain airborne spread of tuberculosis.

234. A 50-year-old man on standard tuberculosis therapy is also taking warfarin. Which agent in his regimen is most likely to reduce the effectiveness of the warfarin through enzyme induction?
     • Isoniazid
     • Ethambutol
     • Rifampin
     • Pyrazinamide

     Correct answer: Rifampin

     Rifampin is correct because it is a potent inducer of hepatic cytochrome enzymes and accelerates the metabolism of many drugs, including warfarin, reducing their effect. Isoniazid, ethambutol, and pyrazinamide do not cause the same clinically significant enzyme induction that lowers warfarin levels.

235. A 52-year-old obese man with hypertension reports loud snoring, witnessed apneas, and morning headaches. Which screening tool combination of features is most consistent with a high likelihood of obstructive sleep apnea?
     • Productive cough with rust-colored sputum
     • Dry cough and wheeze with exertion
     • Pleuritic chest pain and hemoptysis
     • Snoring, observed apneas, daytime sleepiness, and elevated blood pressure

     Correct answer: Snoring, observed apneas, daytime sleepiness, and elevated blood pressure

     Snoring, observed apneas, daytime sleepiness, and elevated blood pressure is correct because these features, captured in screening tools such as STOP-BANG, identify patients at high risk for obstructive sleep apnea. Exertional wheeze, pleuritic pain with hemoptysis, and rust-colored sputum point toward asthma, pulmonary embolism, and pneumonia rather than sleep-disordered breathing.

236. A 45-year-old man with suspected obstructive sleep apnea is referred for confirmatory testing. Which study is the gold-standard diagnostic test that quantifies the apnea-hypopnea index?
     • Overnight in-laboratory polysomnography
     • Spirometry
     • Arterial blood gas analysis
     • Chest computed tomography

     Correct answer: Overnight in-laboratory polysomnography

     Overnight in-laboratory polysomnography is correct because it directly measures respiratory events during sleep to calculate the apnea-hypopnea index and is the reference standard for diagnosing obstructive sleep apnea. Spirometry assesses airflow obstruction, arterial blood gases evaluate gas exchange, and chest computed tomography images lung structure rather than sleep physiology.

237. A 50-year-old man with moderate to severe obstructive sleep apnea and significant daytime sleepiness is selecting therapy. Which treatment is considered first-line and most effective for moderate to severe disease?
     • A nightly hypnotic
     • Continuous positive airway pressure
     • An oral decongestant
     • Supplemental oxygen alone

     Correct answer: Continuous positive airway pressure

     Continuous positive airway pressure is correct because it pneumatically splints the upper airway open and is the first-line, most effective treatment for moderate to severe obstructive sleep apnea. A hypnotic can worsen apnea, an oral decongestant does not relieve airway collapse, and supplemental oxygen alone does not prevent the obstructive events.

238. A patient with untreated severe obstructive sleep apnea is at increased long-term risk for which cardiovascular complication?
     • Bradycardia at rest as the dominant outcome
     • Hypotension
     • Resistant hypertension
     • Reduced risk of atrial fibrillation

     Correct answer: Resistant hypertension

     Resistant hypertension is correct because recurrent nocturnal hypoxemia and sympathetic activation from untreated obstructive sleep apnea contribute to difficult-to-control hypertension and other cardiovascular disease. Untreated apnea is associated with higher rather than lower blood pressure and an increased, not decreased, risk of atrial fibrillation, so the other options misstate the established associations.

239. A 68-year-old woman with severe COPD and chronic hypoxemia develops lower extremity edema, jugular venous distention, and a loud pulmonic component of the second heart sound. Which complication of advanced COPD does this presentation most likely represent?
     • Aortic dissection
     • Left-sided systolic heart failure from ischemia
     • Constrictive pericarditis
     • Cor pulmonale from pulmonary hypertension

     Correct answer: Cor pulmonale from pulmonary hypertension

     Cor pulmonale from pulmonary hypertension is correct because chronic hypoxemia in advanced COPD raises pulmonary vascular resistance, leading to right ventricular strain with peripheral edema, jugular venous distention, and an accentuated pulmonic heart sound. Left-sided ischemic failure, constrictive pericarditis, and aortic dissection do not fit this hypoxemia-driven right heart picture in COPD.

240. A 33-year-old woman with allergic asthma poorly controlled on inhaled therapy has elevated total immunoglobulin E and documented sensitization to perennial allergens. Which biologic add-on therapy specifically targets immunoglobulin E in this allergic phenotype?
     • An anti-immunoglobulin E monoclonal antibody
     • An inhaled short-acting beta-2 agonist
     • An oral leukotriene receptor antagonist
     • A long-acting muscarinic antagonist

     Correct answer: An anti-immunoglobulin E monoclonal antibody

     An anti-immunoglobulin E monoclonal antibody is correct because this biologic binds free immunoglobulin E and is indicated for moderate to severe allergic asthma with elevated immunoglobulin E that remains uncontrolled on standard inhaled therapy. A short-acting beta-2 agonist provides only acute relief, a leukotriene antagonist is a non-biologic controller, and a long-acting muscarinic antagonist does not target the immunoglobulin E pathway.

241. A clinician reviews a chest radiograph for a patient with suspected community-acquired pneumonia complicated by a parapneumonic effusion. The radiograph shows blunting of the costophrenic angle. Which finding does this most directly indicate?
     • A pneumothorax
     • Free pleural fluid
     • Hyperinflation
     • A cavitary lesion

     Correct answer: Free pleural fluid

     Free pleural fluid is correct because blunting of the costophrenic angle on an upright chest radiograph reflects fluid accumulating in the dependent pleural space, as can occur with a parapneumonic effusion. A pneumothorax shows a pleural line with absent peripheral markings, hyperinflation shows flattened diaphragms, and a cavity appears as a lucency within a consolidation.

242. A 40-year-old patient with active pulmonary tuberculosis is treated with directly observed therapy. What is the primary purpose of using directly observed therapy in tuberculosis management?
     • To reduce the total number of medications required
     • To shorten therapy to under one month
     • To ensure adherence and reduce the development of drug resistance
     • To replace the need for sputum follow-up

     Correct answer: To ensure adherence and reduce the development of drug resistance

     Ensuring adherence and reducing drug resistance is correct because directly observed therapy has a trained observer watch the patient take each dose, improving completion and preventing the resistance that arises from inconsistent treatment. It does not reduce the number of drugs, does not shorten the course to under a month, and does not eliminate the need for sputum monitoring.

243. A 70-year-old man with COPD asks why his clinician prefers a long-acting muscarinic antagonist over a short-acting agent for daily maintenance. Which advantage best explains this choice?
     • It reverses established emphysema
     • It works only as a rescue inhaler
     • It is an anti-inflammatory corticosteroid
     • It provides sustained bronchodilation with once or twice daily dosing for maintenance

     Correct answer: It provides sustained bronchodilation with once or twice daily dosing for maintenance

     Providing sustained bronchodilation with infrequent dosing is correct because a long-acting muscarinic antagonist maintains airway patency throughout the day, improving symptoms and reducing exacerbations as maintenance therapy. It is not a rescue-only agent, it is a bronchodilator rather than a corticosteroid, and no inhaled drug reverses established emphysematous destruction.

244. A patient with a large symptomatic pleural effusion undergoes therapeutic thoracentesis. Which complication should the clinician monitor for if an excessively large volume of fluid is removed too rapidly?
     • Re-expansion pulmonary edema
     • Acute appendicitis
     • Carpal tunnel syndrome
     • Migraine headache

     Correct answer: Re-expansion pulmonary edema

     Re-expansion pulmonary edema is correct because rapid removal of a large volume of pleural fluid can cause the suddenly re-expanded lung to develop edema, so drainage volume is generally limited. Appendicitis, carpal tunnel syndrome, and migraine are unrelated to the mechanics of pleural fluid removal.

245. A 24-year-old woman presents with acute dyspnea, pleuritic chest pain, and clear breath sounds. She uses combined oral contraceptives and recently took a 10-hour flight. Which diagnosis should be considered most urgently given these risk factors?
     • Acute sinusitis
     • Acute pulmonary embolism
     • Gastroesophageal reflux
     • Tension headache

     Correct answer: Acute pulmonary embolism

     Acute pulmonary embolism is correct because estrogen-containing contraception and recent prolonged immobility from air travel are venous thromboembolism risk factors, and sudden pleuritic dyspnea with clear lungs is a classic embolism presentation. Sinusitis, reflux, and a tension headache do not explain acute dyspnea with these thrombotic risk factors.

246. A 55-year-old patient newly diagnosed with severe obstructive sleep apnea is preparing for elective surgery requiring general anesthesia. Why is identifying the sleep apnea important for perioperative planning?
     • It eliminates the need for postoperative monitoring
     • It guarantees the surgery cannot proceed
     • It increases sensitivity to sedatives and opioids with greater postoperative respiratory risk
     • It has no bearing on anesthesia

     Correct answer: It increases sensitivity to sedatives and opioids with greater postoperative respiratory risk

     Increased sensitivity to sedatives and opioids with greater postoperative respiratory risk is correct because patients with obstructive sleep apnea are prone to airway collapse and respiratory depression after anesthesia, requiring careful drug selection and enhanced monitoring. The diagnosis does not preclude surgery, does not remove the need for monitoring, and is clearly relevant to anesthetic management.

247. A clinician is differentiating chronic bronchitis from emphysema, two forms within the COPD spectrum. Which clinical definition correctly describes chronic bronchitis?
     • Permanent enlargement of airspaces distal to the terminal bronchioles
     • Acute infection of the lung parenchyma
     • Reversible bronchospasm with normal lung function between flares
     • A productive cough for at least 3 months in each of 2 consecutive years

     Correct answer: A productive cough for at least 3 months in each of 2 consecutive years

     A productive cough for at least 3 months in each of two consecutive years is correct because chronic bronchitis is defined clinically by this duration of chronic sputum production. Permanent airspace enlargement describes emphysema, reversible bronchospasm with normal interval function describes asthma, and acute parenchymal infection describes pneumonia.

248. A 60-year-old man with confirmed pulmonary embolism is started on a parenteral anticoagulant in the hospital before transition to oral therapy. Which class of agent provides immediate anticoagulation for acute pulmonary embolism?
     • Low-molecular-weight heparin
     • Aspirin
     • An inhaled corticosteroid
     • A statin

     Correct answer: Low-molecular-weight heparin

     Low-molecular-weight heparin is correct because it provides rapid therapeutic anticoagulation for acute pulmonary embolism and can bridge to or be replaced by oral agents. Aspirin offers inadequate anticoagulation for acute embolism, an inhaled corticosteroid treats airway inflammation, and a statin lowers cholesterol rather than preventing clot propagation.

249. A 30-year-old man with mild persistent asthma is well controlled on a low-dose inhaled corticosteroid and has had no symptoms or rescue inhaler use for several months. Which adjustment to his therapy is most appropriate at this point?
     • Immediately stop all controller medication
     • Consider a step-down in therapy while monitoring control
     • Begin chronic oral corticosteroids
     • Add a biologic agent

     Correct answer: Consider a step-down in therapy while monitoring control

     Considering a step-down while monitoring control is correct because asthma that has been well controlled for a sustained period can have therapy carefully reduced to the lowest effective dose, with ongoing monitoring for recurrence. Abruptly stopping all controllers risks loss of control, a biologic is reserved for severe disease, and chronic oral corticosteroids are inappropriate for well-controlled mild asthma.

250. A 65-year-old man with severe COPD and chronic hypercapnia is admitted for an exacerbation. As his clinician evaluates his arterial blood gas, which finding best characterizes the ventilatory failure typical of an advanced COPD exacerbation?
     • A low carbon dioxide level with respiratory alkalosis
     • A normal arterial blood gas
     • An elevated carbon dioxide level with respiratory acidosis
     • A metabolic alkalosis with low chloride

     Correct answer: An elevated carbon dioxide level with respiratory acidosis

     An elevated carbon dioxide level with respiratory acidosis is correct because severe airflow obstruction in a COPD exacerbation impairs ventilation, causing carbon dioxide retention and a fall in pH. A low carbon dioxide with alkalosis reflects hyperventilation, a normal blood gas would not indicate ventilatory failure, and a chloride-responsive metabolic alkalosis is not the hallmark of hypercapnic respiratory failure.

251. A 50-year-old man with severe community-acquired pneumonia is admitted with hypoxemia, multilobar infiltrates, and a respiratory rate of 34 breaths per minute requiring vasopressor support. Which disposition is most appropriate for this severity of illness?
     • Discharge home on oral antibiotics
     • A general medical-surgical floor bed only
     • Observation in the emergency department without admission
     • Admission to an intensive care unit

     Correct answer: Admission to an intensive care unit

     Admission to an intensive care unit is correct because severe community-acquired pneumonia with respiratory failure, multilobar disease, and the need for vasopressor support indicates the level of organ support that only intensive care can provide. Home discharge, a routine floor bed, and emergency department observation would all under-resource a critically ill patient.

252. A 48-year-old man reports a burning retrosternal sensation that worsens after meals and when lying flat, occurring three to four times per week for two months. He has no dysphagia, weight loss, or anemia. Which intervention is the most appropriate first-line treatment for his symptoms?
     • Immediate upper endoscopy with biopsy
     • A 24-hour ambulatory esophageal pH study
     • An 8-week course of a once-daily proton pump inhibitor before breakfast
     • Long-term high-dose H2 receptor antagonist therapy at bedtime

     Correct answer: An 8-week course of a once-daily proton pump inhibitor before breakfast

     An 8-week empiric trial of a once-daily proton pump inhibitor taken before breakfast is the correct first-line treatment for typical GERD without alarm features. PPIs suppress gastric acid more effectively than H2 blockers and confirm the diagnosis through symptom response. Endoscopy and pH testing are reserved for alarm symptoms or treatment failure, neither present here.

253. A 55-year-old woman with chronic reflux develops new-onset difficulty swallowing solids, a 10-pound unintentional weight loss, and iron deficiency anemia. Which action is the most appropriate next step in her management?
     • Add a prokinetic agent and reassess in three months
     • Double the dose of her current proton pump inhibitor
     • Recommend dietary and lifestyle modifications alone
     • Refer for upper endoscopy to evaluate for an underlying mucosal lesion

     Correct answer: Refer for upper endoscopy to evaluate for an underlying mucosal lesion

     Upper endoscopy is the most appropriate next step because dysphagia, weight loss, and anemia are alarm features that mandate direct mucosal visualization to exclude esophageal malignancy or Barrett esophagus. Escalating acid suppression or relying on lifestyle changes would dangerously delay diagnosis of a possible cancer in a patient with reflux-associated red flags.

254. A patient with poorly controlled GERD undergoes endoscopy that reveals salmon-colored mucosa extending above the gastroesophageal junction, with biopsy confirming intestinal metaplasia without dysplasia. This finding most directly increases the patient's risk for which condition?
     • Achalasia
     • Esophageal adenocarcinoma
     • Squamous cell carcinoma of the esophagus
     • Esophageal varices

     Correct answer: Esophageal adenocarcinoma

     Esophageal adenocarcinoma is the correct answer because Barrett esophagus, defined by intestinal metaplasia replacing normal squamous epithelium due to chronic acid reflux, is the principal premalignant precursor to adenocarcinoma. Squamous cell carcinoma is linked to smoking and alcohol rather than reflux, and varices arise from portal hypertension, not metaplasia.

255. A 60-year-old man presents with epigastric pain that improves with eating and recurs two to three hours after meals. Testing confirms Helicobacter pylori infection. Which regimen is the most appropriate eradication therapy?
     • Amoxicillin monotherapy for 10 days
     • An H2 blocker plus sucralfate for 6 weeks
     • A proton pump inhibitor alone for 8 weeks
     • A proton pump inhibitor plus clarithromycin and amoxicillin for 14 days

     Correct answer: A proton pump inhibitor plus clarithromycin and amoxicillin for 14 days

     Triple therapy with a proton pump inhibitor plus clarithromycin and amoxicillin for 14 days is the correct eradication regimen for H. pylori-associated peptic ulcer disease in areas without high clarithromycin resistance. Acid suppression alone or single antibiotics will not eradicate the organism, and failure to eradicate leads to ulcer recurrence.

256. A patient completes triple therapy for an H. pylori-associated duodenal ulcer. Which method is the most appropriate to confirm eradication after treatment?
     • Urea breath test performed at least 4 weeks after completing therapy
     • No confirmatory testing is needed if symptoms resolve
     • Serum H. pylori IgG antibody titer one week after therapy
     • Repeat endoscopy with biopsy immediately after the last dose

     Correct answer: Urea breath test performed at least 4 weeks after completing therapy

     A urea breath test performed at least four weeks after completing therapy is the correct confirmation method because it detects active infection and avoids false negatives from recent antibiotic or PPI use. Serology cannot distinguish active from past infection, and symptom resolution alone is unreliable for confirming eradication.

257. A 50-year-old man taking daily naproxen for chronic knee pain develops gnawing epigastric discomfort and tests negative for H. pylori. Endoscopy reveals a gastric ulcer. Beyond acid suppression, which intervention most directly addresses the cause of his ulcer?
     • Discontinue the nonsteroidal anti-inflammatory drug
     • Add a bedtime H2 receptor antagonist indefinitely
     • Initiate a low-residue diet
     • Begin a clarithromycin-based antibiotic regimen

     Correct answer: Discontinue the nonsteroidal anti-inflammatory drug

     Discontinuing the nonsteroidal anti-inflammatory drug is the most direct intervention because NSAID-induced prostaglandin inhibition is the underlying cause of this H. pylori-negative gastric ulcer. Antibiotics are unnecessary without infection, and continuing the NSAID would perpetuate mucosal injury despite acid suppression.

258. A 45-year-old man with a history of heavy alcohol use presents with severe, constant epigastric pain radiating to the back, nausea, and vomiting. His lipase is markedly elevated at more than three times the upper limit of normal. Which diagnosis best explains this presentation?
     • Acute cholecystitis
     • Mesenteric ischemia
     • Acute pancreatitis
     • Perforated peptic ulcer

     Correct answer: Acute pancreatitis

     Acute pancreatitis is the correct diagnosis because epigastric pain radiating to the back with a lipase elevated more than three times the upper limit of normal meets diagnostic criteria, and alcohol is a leading etiology. Cholecystitis localizes to the right upper quadrant, and a perforated ulcer typically produces a rigid abdomen with free air.

259. A patient diagnosed with acute pancreatitis has no gallstones on ultrasound and reports no alcohol use. Which laboratory abnormality should be evaluated as a potential metabolic cause of the pancreatitis?
     • Elevated serum ferritin
     • Marked hypertriglyceridemia
     • Elevated serum uric acid
     • Low serum albumin

     Correct answer: Marked hypertriglyceridemia

     Marked hypertriglyceridemia is the correct answer because triglyceride levels typically above 1,000 mg/dL are a well-established cause of acute pancreatitis when gallstones and alcohol are excluded. Ferritin, albumin, and uric acid abnormalities are not recognized direct precipitants of pancreatic inflammation.

260. A patient hospitalized with acute pancreatitis is being assessed for disease severity. Which component is part of the Ranson criteria used to predict prognosis at admission?
     • Body mass index
     • Presence of gallstones on ultrasound
     • Serum lipase level
     • Age greater than 55 years

     Correct answer: Age greater than 55 years

     Age greater than 55 years is the correct answer because it is one of the admission Ranson criteria, along with white blood cell count, glucose, LDH, and AST. Lipase confirms the diagnosis but is not a severity predictor, and gallstones and body mass index are not part of the Ranson scoring system.

261. A 65-year-old woman presents with left lower quadrant pain, low-grade fever, and a change in bowel habits. Examination reveals localized tenderness without peritoneal signs. CT confirms acute uncomplicated sigmoid diverticulitis. Which management approach is most appropriate for this stable patient?
     • Long-term proton pump inhibitor therapy
     • Emergent sigmoid colectomy
     • Immediate colonoscopy during the acute episode
     • Outpatient supportive care with oral antibiotics and dietary modification

     Correct answer: Outpatient supportive care with oral antibiotics and dietary modification

     Outpatient management with supportive care, selective oral antibiotics, and dietary modification is most appropriate for stable acute uncomplicated diverticulitis without abscess, perforation, or peritonitis. Emergent surgery is reserved for complications, and colonoscopy during the acute phase increases perforation risk and should be deferred for several weeks.

262. A patient recovering from an episode of acute diverticulitis asks when colon evaluation should occur. Which recommendation is most appropriate regarding follow-up colonoscopy?
     • Perform colonoscopy immediately while symptoms are present
     • Schedule colonoscopy approximately 6 to 8 weeks after the acute episode resolves
     • Avoid colonoscopy entirely after diverticulitis
     • Repeat colonoscopy weekly until symptoms resolve

     Correct answer: Schedule colonoscopy approximately 6 to 8 weeks after the acute episode resolves

     Colonoscopy approximately six to eight weeks after resolution is the correct recommendation because it allows mucosal inflammation to subside and excludes underlying malignancy that can mimic diverticulitis. Endoscopy during acute inflammation risks perforation, and forgoing evaluation entirely could miss a colorectal cancer.

263. A 40-year-old obese woman presents with right upper quadrant pain after a fatty meal, accompanied by fever and a positive Murphy sign. Ultrasound shows a thickened gallbladder wall and pericholecystic fluid with gallstones. Which diagnosis best fits this presentation?
     • Acute hepatitis
     • Acute cholecystitis
     • Symptomatic cholelithiasis without inflammation
     • Choledocholithiasis with cholangitis

     Correct answer: Acute cholecystitis

     Acute cholecystitis is the correct diagnosis because fever, a positive Murphy sign, and ultrasound findings of gallbladder wall thickening and pericholecystic fluid indicate gallbladder inflammation rather than uncomplicated biliary colic. Hepatitis produces diffuse liver inflammation, and ascending cholangitis features jaundice and biliary obstruction.

264. A 38-year-old woman has recurrent episodes of postprandial right upper quadrant pain lasting several hours, with ultrasound confirming gallstones but no wall thickening, fever, or leukocytosis. Which management is most appropriate for her symptomatic cholelithiasis?
     • Lifelong proton pump inhibitor therapy
     • Referral for elective laparoscopic cholecystectomy
     • Emergent cholecystectomy within 24 hours
     • Immediate broad-spectrum intravenous antibiotics

     Correct answer: Referral for elective laparoscopic cholecystectomy

     Elective laparoscopic cholecystectomy is most appropriate for recurrent symptomatic cholelithiasis without signs of acute inflammation. Emergent surgery and intravenous antibiotics are reserved for acute cholecystitis or cholangitis, and proton pump inhibitors do not treat gallstone disease.

265. A patient with gallstones develops jaundice, fever with rigors, and right upper quadrant pain. Laboratory results show elevated bilirubin and alkaline phosphatase. This triad of findings is most consistent with which complication of gallstone disease?
     • Ascending cholangitis
     • Acute pancreatitis
     • Uncomplicated biliary colic
     • Hepatic abscess

     Correct answer: Ascending cholangitis

     Ascending cholangitis is the correct answer because the Charcot triad of fever, jaundice, and right upper quadrant pain with cholestatic laboratory findings indicates infection of an obstructed biliary tree. Biliary colic lacks fever and jaundice, and while pancreatitis can coexist, the cholestatic jaundice pattern points specifically to biliary obstruction with infection.

266. A 28-year-old woman reports recurrent abdominal pain relieved by defecation, alternating constipation and diarrhea, and bloating for over six months. Workup including labs, colonoscopy, and celiac serology is normal. Which diagnostic framework best supports a diagnosis of irritable bowel syndrome?
     • The Centor criteria based on clinical features
     • The Rome IV criteria based on recurrent abdominal pain related to defecation and altered stool form or frequency
     • The Light criteria based on fluid protein ratios
     • The Ranson criteria based on metabolic parameters

     Correct answer: The Rome IV criteria based on recurrent abdominal pain related to defecation and altered stool form or frequency

     The Rome IV criteria are correct because IBS is a clinical diagnosis defined by recurrent abdominal pain at least one day per week associated with defecation and changes in stool frequency or form. Ranson criteria assess pancreatitis severity, Light criteria classify pleural effusions, and Centor criteria evaluate pharyngitis, none of which apply to IBS.

267. A patient meeting Rome IV criteria for irritable bowel syndrome with predominant constipation has inadequate relief despite increased dietary fiber and exercise. Which finding would be a red flag prompting further investigation rather than a diagnosis of IBS?
     • Symptom worsening with stress
     • Bloating that fluctuates throughout the day
     • Rectal bleeding with unintentional weight loss
     • Pain relieved after a bowel movement

     Correct answer: Rectal bleeding with unintentional weight loss

     Rectal bleeding with unintentional weight loss is the correct red flag because such alarm features are inconsistent with IBS and require evaluation for organic disease such as malignancy or inflammatory bowel disease. Stress-related symptoms, pain relieved by defecation, and fluctuating bloating are typical features of IBS itself.

268. A 22-year-old man presents with periumbilical pain that migrated to the right lower quadrant, anorexia, low-grade fever, and tenderness at McBurney point. Which diagnosis best explains these findings?
     • Mesenteric adenitis
     • Acute diverticulitis
     • Inflammatory bowel disease flare
     • Acute appendicitis

     Correct answer: Acute appendicitis

     Acute appendicitis is the correct diagnosis because periumbilical pain migrating to the right lower quadrant with anorexia, fever, and McBurney point tenderness is the classic presentation. Diverticulitis typically affects the left lower quadrant, and the acute migratory pattern with localized peritoneal signs is most characteristic of appendiceal inflammation.

269. A 19-year-old woman with suspected appendicitis has equivocal physical findings, and the clinician wishes to confirm the diagnosis while avoiding ionizing radiation. Which imaging study is the most appropriate initial choice?
     • Contrast-enhanced CT of the abdomen and pelvis
     • Graded compression abdominal ultrasound
     • Plain abdominal radiography
     • Barium enema

     Correct answer: Graded compression abdominal ultrasound

     Graded compression abdominal ultrasound is the most appropriate initial study in a young woman when avoiding radiation is desired, as it can identify a noncompressible, enlarged appendix. CT is highly accurate but involves radiation, plain films are insensitive for appendicitis, and barium enema is not used for acute appendicitis.

270. A patient with appendicitis develops diffuse abdominal rigidity, rebound tenderness, and worsening fever several hours after symptom onset. Which complication should be most strongly suspected?
     • Uncomplicated biliary colic
     • Functional constipation
     • Perforation with peritonitis
     • Resolving appendicitis

     Correct answer: Perforation with peritonitis

     Perforation with peritonitis is the most likely complication because diffuse rigidity, rebound tenderness, and worsening fever indicate the inflamed appendix has ruptured, spilling contents into the peritoneal cavity. These signs of generalized peritoneal irritation distinguish perforation from uncomplicated, localized appendicitis and demand urgent surgical management.

271. A 26-year-old man presents with bloody diarrhea, tenesmus, and lower abdominal cramping. Colonoscopy reveals continuous inflammation extending proximally from the rectum without skip lesions, limited to the mucosa. Which diagnosis best fits these findings?
     • Ulcerative colitis
     • Ischemic colitis
     • Diverticulitis
     • Crohn disease

     Correct answer: Ulcerative colitis

     Ulcerative colitis is correct because continuous mucosal inflammation extending proximally from the rectum without skip lesions is its defining pattern. Crohn disease characteristically produces transmural inflammation with skip lesions anywhere in the GI tract, distinguishing it from the confluent rectal-to-proximal involvement seen here.

272. A 30-year-old woman with chronic diarrhea, weight loss, and a perianal fistula undergoes colonoscopy showing patchy transmural inflammation with skip lesions and cobblestoning of the terminal ileum. Which feature most strongly distinguishes her condition from ulcerative colitis?
     • Transmural inflammation with skip lesions
     • Continuous inflammation limited to the colon
     • Involvement that always begins in the rectum
     • Inflammation confined to the mucosal layer

     Correct answer: Transmural inflammation with skip lesions

     Transmural inflammation with skip lesions is the most distinguishing feature of Crohn disease, which can involve any portion of the GI tract and penetrate the full bowel wall, producing fistulas and cobblestoning. Continuous mucosal inflammation beginning in the rectum is characteristic of ulcerative colitis instead.

273. A patient with long-standing ulcerative colitis involving the entire colon asks about cancer surveillance. Which long-term complication most justifies regular surveillance colonoscopy in this patient?
     • Increased risk of gallstone formation
     • Increased risk of peptic ulcer disease
     • Increased risk of colorectal cancer
     • Increased risk of esophageal varices

     Correct answer: Increased risk of colorectal cancer

     Increased risk of colorectal cancer is the correct answer because chronic colonic inflammation in extensive, long-standing ulcerative colitis substantially raises colorectal cancer risk, justifying periodic surveillance colonoscopy with biopsies. Varices, gallstones, and peptic ulcers are not the principal cancer-prevention rationale for surveillance in ulcerative colitis.

274. A patient with Crohn disease involving the terminal ileum reports fatigue and is found to have a macrocytic anemia. Which deficiency most directly explains this finding given the location of disease?
     • Iron deficiency
     • Folate deficiency from dietary inadequacy
     • Vitamin B12 deficiency
     • Vitamin C deficiency

     Correct answer: Vitamin B12 deficiency

     Vitamin B12 deficiency is correct because the terminal ileum is the site of B12 absorption, and Crohn disease or surgical resection there impairs uptake, producing macrocytic anemia. Iron deficiency causes microcytic anemia, and folate deficiency, while also macrocytic, is not specifically tied to terminal ileal disease.

275. A 35-year-old man with several weeks of fatigue, jaundice, and right upper quadrant discomfort has markedly elevated ALT and AST with positive hepatitis B surface antigen and IgM anti-hepatitis B core antibody. Which diagnosis best explains this serologic pattern?
     • Hepatitis B vaccine-induced immunity
     • Chronic inactive hepatitis B carrier state
     • Acute hepatitis B infection
     • Resolved hepatitis B with immunity

     Correct answer: Acute hepatitis B infection

     Acute hepatitis B infection is correct because the presence of hepatitis B surface antigen with IgM antibody to the hepatitis B core antigen indicates active, recent infection. Resolved infection and vaccine immunity show surface antibody without surface antigen, and the IgM core antibody specifically marks the acute phase.

276. A patient is found to have isolated positive hepatitis B surface antibody with negative surface antigen and negative core antibody. Which interpretation of this serologic profile is correct?
     • Active acute hepatitis B infection
     • Past natural infection that has resolved
     • Immunity from hepatitis B vaccination
     • Chronic hepatitis B infection

     Correct answer: Immunity from hepatitis B vaccination

     Immunity from vaccination is correct because the hepatitis B vaccine contains only surface antigen, producing isolated surface antibody without core antibody. Natural resolved infection would also show core antibody, and active infection would show surface antigen, so the isolated surface antibody indicates vaccine-induced protection.

277. A 50-year-old man with a history of injection drug use is screened and found to have a positive hepatitis C antibody. Which test is the most appropriate next step to determine whether he has active infection?
     • Hepatitis C RNA viral load by polymerase chain reaction
     • Hepatitis A IgM antibody
     • Liver biopsy
     • Repeat hepatitis C antibody in six months

     Correct answer: Hepatitis C RNA viral load by polymerase chain reaction

     Hepatitis C RNA viral load testing is the correct next step because a positive antibody indicates exposure but cannot distinguish active from cleared infection; detectable RNA confirms chronic active infection requiring treatment. Repeat serology, biopsy, and hepatitis A testing do not establish whether the hepatitis C infection is currently active.

278. A 58-year-old man with a long history of alcohol use presents with abdominal distension, jaundice, palmar erythema, and spider angiomata. Ultrasound shows a nodular, shrunken liver with ascites. Which complication arises directly from the portal hypertension associated with his cirrhosis?
     • Esophageal varices
     • Peptic ulcer disease
     • Acute cholecystitis
     • Acute appendicitis

     Correct answer: Esophageal varices

     Esophageal varices are correct because portal hypertension from cirrhosis diverts blood through portosystemic collaterals, causing dilated submucosal veins in the esophagus that can bleed catastrophically. Appendicitis, peptic ulcer disease, and cholecystitis are unrelated to the elevated portal pressure that defines this complication.

279. A patient with cirrhosis develops confusion, asterixis, and a sweet musty breath odor. Which intervention most directly targets the pathophysiology of this complication?
     • Intravenous proton pump inhibitor
     • Lactulose to reduce ammonia absorption
     • Oral iron supplementation
     • Broad-spectrum antifungal therapy

     Correct answer: Lactulose to reduce ammonia absorption

     Lactulose is correct because hepatic encephalopathy results from accumulation of ammonia and other nitrogenous toxins the failing liver cannot clear; lactulose acidifies the colon and traps ammonia for excretion. Proton pump inhibitors, iron, and antifungals do not address the ammonia-driven mechanism of encephalopathy.

280. A patient with cirrhosis and new-onset ascites develops fever and diffuse abdominal pain. Diagnostic paracentesis shows an ascitic fluid neutrophil count above 250 cells per microliter. Which diagnosis does this finding confirm?
     • Hepatorenal syndrome
     • Hepatic encephalopathy
     • Portal vein thrombosis
     • Spontaneous bacterial peritonitis

     Correct answer: Spontaneous bacterial peritonitis

     Spontaneous bacterial peritonitis is correct because an ascitic fluid absolute neutrophil count above 250 cells per microliter is diagnostic, even before culture results return, and warrants prompt antibiotics. Hepatorenal syndrome is a renal complication, encephalopathy is neurologic, and portal vein thrombosis is vascular, none defined by the ascitic neutrophil count.

281. A 65-year-old man on warfarin presents with hematemesis and melena. He is tachycardic and hypotensive. After airway and hemodynamic stabilization, which intervention is the most appropriate initial step for this upper gastrointestinal bleed?
     • Outpatient oral proton pump inhibitor and follow-up in one week
     • Immediate colonoscopy
     • Aggressive intravenous fluid resuscitation and intravenous proton pump inhibitor with urgent endoscopy
     • Oral iron supplementation alone

     Correct answer: Aggressive intravenous fluid resuscitation and intravenous proton pump inhibitor with urgent endoscopy

     Aggressive intravenous fluid resuscitation with an intravenous proton pump inhibitor and urgent endoscopy is correct for a hemodynamically unstable upper GI bleed, addressing both volume loss and the bleeding source. Outpatient management and oral iron are inadequate for active bleeding, and colonoscopy targets the lower, not upper, GI tract.

282. A 70-year-old woman reports passing bright red blood per rectum with clots and lightheadedness. She is hemodynamically stable. Which diagnostic study is most appropriate to localize the source of this lower gastrointestinal bleed?
     • Abdominal plain radiography
     • Upper endoscopy as the first study
     • Esophageal pH monitoring
     • Colonoscopy after bowel preparation

     Correct answer: Colonoscopy after bowel preparation

     Colonoscopy after bowel preparation is correct because it both localizes and can treat lower GI bleeding sources such as diverticulosis or angiodysplasia in a stable patient. Upper endoscopy targets a different anatomic region, pH monitoring evaluates reflux, and plain films cannot identify a bleeding source.

283. A patient with an upper gastrointestinal bleed has a markedly elevated blood urea nitrogen relative to creatinine. Which mechanism best explains this laboratory pattern?
     • Intestinal digestion and absorption of blood proteins
     • Hepatic synthesis of urea is suppressed
     • Dehydration from vomiting alone
     • Acute glomerulonephritis

     Correct answer: Intestinal digestion and absorption of blood proteins

     Digestion and absorption of blood proteins in the small intestine is correct because hemoglobin breakdown delivers a nitrogen load that is absorbed and converted to urea, disproportionately raising the BUN relative to creatinine in upper GI bleeding. Glomerulonephritis, isolated dehydration, and suppressed hepatic synthesis do not produce this characteristic upper-GI-bleed pattern.

284. A 30-year-old woman reports chronic diarrhea, bloating, weight loss, and an itchy vesicular rash on her elbows. Serologic testing shows elevated tissue transglutaminase IgA antibodies. Which diagnosis best fits this clinical picture?
     • Ulcerative colitis
     • Acute viral gastroenteritis
     • Celiac disease
     • Lactose intolerance

     Correct answer: Celiac disease

     Celiac disease is correct because chronic malabsorptive diarrhea, weight loss, the associated dermatitis herpetiformis rash, and positive tissue transglutaminase IgA antibodies together point to gluten-sensitive enteropathy. Lactose intolerance lacks the serologic and dermatologic findings, and the antibody profile is specific to celiac disease rather than colitis or acute infection.

285. A patient with suspected celiac disease has positive tissue transglutaminase antibodies. Which procedure is most appropriate to confirm the diagnosis before committing to lifelong dietary therapy?
     • Small bowel biopsy showing villous atrophy while on a gluten-containing diet
     • Hydrogen breath testing
     • Empiric gluten-free diet without further testing
     • Colonoscopy with random colonic biopsies

     Correct answer: Small bowel biopsy showing villous atrophy while on a gluten-containing diet

     Small bowel biopsy demonstrating villous atrophy while the patient still consumes gluten is the correct confirmatory step, as it documents the characteristic histology and prevents false negatives from premature dietary changes. Colonoscopy and breath testing assess other conditions, and confirming the diagnosis before lifelong dietary commitment is preferred over empiric treatment.

286. A 25-year-old man experiences bloating, cramping, and watery diarrhea within a few hours of consuming dairy products, with complete resolution when he avoids milk. His celiac serology is negative. Which mechanism best explains his symptoms?
     • Bacterial overgrowth from antibiotic use
     • Autoimmune destruction of intestinal villi
     • Pancreatic exocrine insufficiency
     • Deficiency of intestinal lactase enzyme

     Correct answer: Deficiency of intestinal lactase enzyme

     Lactase enzyme deficiency is correct because the inability to hydrolyze lactose leads to osmotic diarrhea and gas when undigested lactose reaches the colon, with symptoms tied specifically to dairy and resolving with avoidance. Villous autoimmunity describes celiac disease, which his negative serology excludes, and the dairy-specific pattern points to lactose malabsorption.

287. A 52-year-old asymptomatic man with no family history of colon cancer asks when to begin colorectal cancer screening. According to current average-risk guidelines, at what age should screening typically begin?
     • Age 45
     • Age 30
     • Age 60
     • Age 75

     Correct answer: Age 45

     Age 45 is correct because current U.S. guidelines recommend starting colorectal cancer screening for average-risk adults at this age, reflecting rising incidence in younger adults. Beginning at 30 is too early without risk factors, and waiting until 60 or 75 would miss the window for early detection in average-risk individuals.

288. A 46-year-old patient prefers a noninvasive colorectal cancer screening test and has no symptoms or family history. Which screening option requires a follow-up colonoscopy if the result is positive?
     • Fecal immunochemical test (FIT)
     • Flexible sigmoidoscopy with biopsy
     • Screening colonoscopy
     • Digital rectal examination

     Correct answer: Fecal immunochemical test (FIT)

     The fecal immunochemical test is correct because it is a noninvasive stool-based test that detects occult blood, and any positive result must be followed by a colonoscopy to evaluate for an underlying lesion. Colonoscopy and sigmoidoscopy are themselves direct visualization tests, and digital rectal exam is not an adequate screening modality.

289. A 48-year-old woman whose father was diagnosed with colorectal cancer at age 50 asks how her family history affects screening. Which recommendation is most appropriate for her?
     • Begin screening only at age 60
     • Begin colonoscopy at age 40 or 10 years before the relative's diagnosis age
     • Use digital rectal examination as her sole screening method
     • Screening is unnecessary because colorectal cancer is not heritable

     Correct answer: Begin colonoscopy at age 40 or 10 years before the relative's diagnosis age

     Beginning colonoscopy at age 40, or 10 years before the affected first-degree relative's diagnosis age, is correct because a positive family history increases risk and warrants earlier and more frequent screening. Delaying to 60, forgoing screening, or relying on rectal exam alone would fail to account for her elevated hereditary risk.

290. A postoperative patient develops crampy abdominal pain, distension, vomiting, and obstipation. Imaging shows dilated loops of small bowel with air-fluid levels and a transition point. Given a prior abdominal surgery, which is the most likely cause of this small bowel obstruction?
     • Sigmoid volvulus
     • Postoperative adhesions
     • Acute appendicitis
     • Hemorrhoidal disease

     Correct answer: Postoperative adhesions

     Postoperative adhesions are correct because they are the most common cause of small bowel obstruction in patients with prior abdominal surgery, producing the classic crampy pain, distension, vomiting, and air-fluid levels with a transition point. Volvulus typically affects the colon, while appendicitis and hemorrhoids do not cause mechanical small bowel obstruction.

291. A patient with a partial small bowel obstruction and no signs of strangulation or peritonitis is admitted. Which initial management approach is most appropriate?
     • Bowel rest, nasogastric decompression, and intravenous fluids
     • Immediate exploratory laparotomy
     • Oral laxatives and discharge home
     • Begin a high-fiber diet immediately

     Correct answer: Bowel rest, nasogastric decompression, and intravenous fluids

     Bowel rest with nasogastric decompression and intravenous fluids is correct because many partial small bowel obstructions without strangulation resolve with conservative management. Immediate surgery is reserved for complete obstruction or signs of ischemia, and laxatives or fiber would worsen a mechanical obstruction.

292. A patient with a bowel obstruction develops fever, tachycardia, localized peritoneal signs, and rising lactate. Which development should prompt urgent surgical intervention?
     • Mild constipation
     • Resolution of the obstruction
     • Bowel strangulation with ischemia
     • Transient nausea

     Correct answer: Bowel strangulation with ischemia

     Bowel strangulation with ischemia is correct because fever, tachycardia, peritoneal signs, and elevated lactate indicate compromised blood supply with impending bowel necrosis, mandating urgent surgery. These features distinguish strangulation, a surgical emergency, from a simple obstruction that may be managed conservatively.

293. A 45-year-old man reports painless, intermittent bright red blood on the toilet paper after bowel movements and occasional anal itching. Examination reveals soft, nontender vascular cushions at the anal verge. Which diagnosis best explains these findings?
     • Colorectal carcinoma
     • Anal fissure
     • Perianal abscess
     • External hemorrhoids

     Correct answer: External hemorrhoids

     External hemorrhoids are correct because painless bright red bleeding with anal itching and soft vascular cushions at the anal verge is characteristic of hemorrhoidal disease. An anal fissure typically causes painful defecation, an abscess produces a tender fluctuant mass, and carcinoma would warrant evaluation but is less consistent with these benign findings.

294. A 38-year-old woman with chronic constipation reports severe, sharp anal pain during and after defecation with small amounts of bright red blood, and examination shows a linear tear in the posterior midline of the anal canal. Which diagnosis best fits this presentation?
     • Internal hemorrhoid prolapse
     • Anal fissure
     • Diverticulitis
     • Pilonidal cyst

     Correct answer: Anal fissure

     Anal fissure is correct because severe pain during and after defecation with a posterior midline linear tear and minimal bright red bleeding is the classic presentation, often precipitated by constipation. Internal hemorrhoids are usually painless, diverticulitis presents with abdominal pain, and a pilonidal cyst occurs in the sacrococcygeal region.

295. A 60-year-old man reports progressive difficulty swallowing solids that has advanced to liquids over three months, along with weight loss and a long history of smoking and alcohol use. Which diagnosis should be most strongly suspected?
     • Achalasia
     • Esophageal carcinoma
     • Diffuse esophageal spasm
     • Eosinophilic esophagitis

     Correct answer: Esophageal carcinoma

     Esophageal carcinoma is the correct answer because progressive dysphagia from solids to liquids with weight loss in an older patient with smoking and alcohol exposure is the classic warning pattern for malignancy. Achalasia and esophageal spasm typically cause dysphagia to both solids and liquids without progressive weight loss, and eosinophilic esophagitis usually affects younger patients with food impaction.

296. A 40-year-old patient reports difficulty swallowing both solids and liquids, regurgitation of undigested food, and a barium study showing a dilated esophagus with a smooth tapering bird-beak narrowing at the gastroesophageal junction. Which diagnosis best fits these findings?
     • Pill-induced esophagitis
     • Zenker diverticulum
     • Achalasia
     • Esophageal carcinoma

     Correct answer: Achalasia

     Achalasia is correct because dysphagia to both solids and liquids with a dilated esophagus and a smooth bird-beak tapering at the gastroesophageal junction reflects failure of lower esophageal sphincter relaxation and absent peristalsis. Carcinoma produces an irregular stricture, Zenker diverticulum causes a pharyngeal pouch, and pill esophagitis causes focal ulceration.

297. A 65-year-old man with chronic alcoholism and poor dietary intake develops confusion, ophthalmoplegia, and gait ataxia. Which vitamin deficiency most directly explains this presentation, requiring urgent repletion before glucose administration?
     • Niacin (vitamin B3)
     • Vitamin D
     • Vitamin K
     • Thiamine (vitamin B1)

     Correct answer: Thiamine (vitamin B1)

     Thiamine deficiency is correct because the triad of confusion, ophthalmoplegia, and ataxia defines Wernicke encephalopathy, which is common in malnourished alcoholics and can be precipitated by glucose given before thiamine. Vitamin D, vitamin K, and niacin deficiencies produce different syndromes and do not cause this acute neurologic triad.

298. A patient with a malabsorptive disorder develops easy bruising and a prolonged prothrombin time that corrects with parenteral supplementation. Which fat-soluble vitamin deficiency most directly explains these findings?
     • Vitamin C
     • Vitamin A
     • Vitamin K
     • Vitamin E

     Correct answer: Vitamin K

     Vitamin K deficiency is correct because vitamin K is required to synthesize clotting factors II, VII, IX, and X, and its deficiency in fat malabsorption prolongs the prothrombin time and causes bleeding that corrects with repletion. Vitamin A deficiency causes visual changes, vitamin E causes neurologic effects, and vitamin C deficiency causes scurvy rather than coagulopathy.

299. A strict vegan patient who takes no supplements develops fatigue, paresthesias, and a macrocytic anemia with hypersegmented neutrophils. Which nutritional deficiency most directly explains these findings?
     • Vitamin B12 deficiency
     • Vitamin C deficiency
     • Zinc deficiency
     • Vitamin A deficiency

     Correct answer: Vitamin B12 deficiency

     Vitamin B12 deficiency is correct because B12 is found primarily in animal products, and its deficiency in an unsupplemented vegan produces macrocytic anemia with hypersegmented neutrophils plus neurologic symptoms such as paresthesias. Vitamin C deficiency causes scurvy, zinc deficiency impairs wound healing and taste, and vitamin A deficiency causes visual changes.

300. A 24-year-old college student develops acute watery diarrhea, nausea, vomiting, and low-grade fever 24 hours after a dormitory outbreak. Symptoms are self-limited and resolve within three days. Which management approach is most appropriate for this viral gastroenteritis?
     • Immediate colonoscopy
     • Empiric broad-spectrum intravenous antibiotics
     • Oral rehydration and supportive care
     • Long-term proton pump inhibitor therapy

     Correct answer: Oral rehydration and supportive care

     Oral rehydration and supportive care is correct because acute viral gastroenteritis is self-limited and managed primarily with fluid and electrolyte replacement. Antibiotics are unnecessary for viral illness and may cause harm, colonoscopy is not indicated for acute self-limited diarrhea, and proton pump inhibitors do not treat infectious gastroenteritis.

301. A patient develops bloody diarrhea, abdominal cramping, and fever several days after eating undercooked poultry. Stool studies are pending. Which feature most distinguishes this inflammatory (invasive) diarrhea from a typical viral gastroenteritis?
     • Complete absence of fever
     • Watery stool without blood
     • Symptom resolution within 12 hours
     • Presence of blood and fecal leukocytes in the stool

     Correct answer: Presence of blood and fecal leukocytes in the stool

     The presence of blood and fecal leukocytes is correct because invasive bacterial pathogens such as Campylobacter cause inflammatory diarrhea marked by bloody stools and leukocytes, distinguishing it from the watery, nonbloody stool of viral gastroenteritis. Absence of fever and very rapid resolution are not characteristic of invasive bacterial colitis.

302. A hospitalized patient on broad-spectrum antibiotics develops profuse watery diarrhea, abdominal cramping, and leukocytosis. Stool testing is positive for Clostridioides difficile toxin. Which initial management step is most appropriate?
     • Continue the current antibiotic and add an antimotility agent
     • Discontinue the inciting antibiotic and begin oral therapy directed at C. difficile
     • Start an empiric proton pump inhibitor
     • Schedule urgent colectomy for all cases

     Correct answer: Discontinue the inciting antibiotic and begin oral therapy directed at C. difficile

     Discontinuing the inciting antibiotic and starting oral therapy directed at C. difficile, such as oral vancomycin or fidaxomicin, is correct because removing the precipitant and treating the organism is foundational. Antimotility agents can precipitate toxic megacolon, proton pump inhibitors do not treat the infection, and colectomy is reserved for fulminant or refractory disease.

303. A 30-year-old man with newly diagnosed Crohn disease is being counseled about modifiable risk factors that worsen disease activity and increase the need for surgery. Which behavior should be most strongly addressed?
     • Adequate hydration
     • Moderate aerobic exercise
     • Routine handwashing
     • Cigarette smoking

     Correct answer: Cigarette smoking

     Cigarette smoking is correct because it is a well-established modifiable factor that worsens Crohn disease activity, increases relapse rates, and raises the likelihood of surgery. Exercise, hydration, and handwashing are not detrimental to Crohn disease, making smoking cessation the priority counseling point.

304. A patient with chronic GERD asks which lifestyle change can reduce reflux symptoms in addition to medication. Which recommendation is most appropriate?
     • Eat one large meal late at night
     • Elevate the head of the bed and avoid eating within three hours of lying down
     • Increase intake of caffeine and chocolate
     • Lie down immediately after meals to aid digestion

     Correct answer: Elevate the head of the bed and avoid eating within three hours of lying down

     Elevating the head of the bed and avoiding late meals is correct because reducing nocturnal acid exposure through positioning and meal timing decreases reflux symptoms. Lying down after meals, consuming caffeine and chocolate, and eating large late meals all relax the lower esophageal sphincter or increase reflux and would worsen symptoms.

305. A 55-year-old man with biopsy-confirmed Barrett esophagus and low-grade dysplasia is counseled on management. Which approach is most appropriate to reduce his risk of progression to esophageal adenocarcinoma?
     • Annual fecal immunochemical testing
     • Immediate total esophagectomy for all low-grade dysplasia
     • No further follow-up after the initial diagnosis
     • Endoscopic surveillance with consideration of endoscopic eradication therapy

     Correct answer: Endoscopic surveillance with consideration of endoscopic eradication therapy

     Endoscopic surveillance with consideration of endoscopic eradication therapy is correct because low-grade dysplasia in Barrett esophagus carries progression risk that warrants close monitoring and possible ablation. Forgoing follow-up risks missing progression, fecal testing screens the colon not the esophagus, and esophagectomy is overly aggressive for low-grade dysplasia.

306. A patient recovering from acute pancreatitis develops persistent abdominal pain and early satiety several weeks later, and imaging reveals a fluid-filled collection adjacent to the pancreas with a defined wall. Which complication does this finding represent?
     • Pancreatic pseudocyst
     • Acute appendicitis
     • Esophageal varices
     • Gallbladder polyp

     Correct answer: Pancreatic pseudocyst

     A pancreatic pseudocyst is correct because a walled fluid collection developing weeks after acute pancreatitis, often causing pain and early satiety, is the classic delayed complication. Appendicitis, varices, and gallbladder polyps are unrelated to the encapsulated peripancreatic fluid collection described here.

307. A 36-year-old woman with irritable bowel syndrome and predominant diarrhea has persistent symptoms despite reassurance and dietary fiber. Which dietary intervention has the strongest evidence for reducing her IBS symptoms?
     • A high-caffeine diet
     • Increasing carbonated beverage intake
     • A diet high in artificial sweeteners
     • A low-FODMAP diet

     Correct answer: A low-FODMAP diet

     A low-FODMAP diet is correct because reducing fermentable oligosaccharides, disaccharides, monosaccharides, and polyols decreases gas, bloating, and diarrhea in many IBS patients and has the strongest dietary evidence base. Caffeine, carbonation, and artificial sweeteners tend to aggravate IBS symptoms rather than relieve them.

308. A 58-year-old asymptomatic patient has an oral glucose tolerance test showing a 2-hour plasma glucose of 215 mg/dL. Repeat testing on a later day yields 208 mg/dL. Which diagnosis do these results establish?
     • Type 2 diabetes mellitus
     • Impaired glucose tolerance only
     • Normal glucose tolerance
     • Reactive hypoglycemia

     Correct answer: Type 2 diabetes mellitus

     Type 2 diabetes mellitus is correct. A 2-hour oral glucose tolerance value of 200 mg/dL or higher, confirmed on a separate day in an asymptomatic patient, meets the diagnostic threshold for diabetes. Both values here exceed 200 mg/dL. Impaired glucose tolerance is defined by a 2-hour value of 140 to 199 mg/dL, which is below these results, and normal tolerance is under 140 mg/dL.

309. A patient presents with classic polyuria, polydipsia, and unintentional weight loss, and a single random plasma glucose measures 312 mg/dL. How should this finding be interpreted?
     • A random glucose of 200 mg/dL or higher with classic symptoms is diagnostic of diabetes
     • A single repeat test on another day is still required before diagnosing diabetes
     • Only an HbA1c can confirm diabetes in this scenario
     • This value indicates prediabetes pending fasting confirmation

     Correct answer: A random glucose of 200 mg/dL or higher with classic symptoms is diagnostic of diabetes

     A random glucose of 200 mg/dL or higher with classic symptoms is diagnostic of diabetes is correct. When a patient has unequivocal hyperglycemic symptoms such as polyuria, polydipsia, and weight loss, a random plasma glucose of 200 mg/dL or above establishes the diagnosis without requiring a second confirmatory test. Repeat or alternative testing is reserved for asymptomatic patients, not this symptomatic presentation.

310. A patient with type 2 diabetes and a body mass index of 36 is started on metformin but remains above goal, and weight loss is a major treatment priority. Which add-on agent best supports both glycemic control and substantial weight reduction?
     • A GLP-1 receptor agonist
     • Glimepiride
     • Pioglitazone
     • Glyburide

     Correct answer: A GLP-1 receptor agonist

     A GLP-1 receptor agonist is correct. This class lowers glucose while promoting clinically meaningful weight loss through delayed gastric emptying and reduced appetite, making it preferred when weight reduction is a priority. Sulfonylureas such as glimepiride and glyburide tend to cause weight gain, and thiazolidinediones like pioglitazone are also associated with weight gain and fluid retention.

311. A patient with type 2 diabetes and stage 3 chronic kidney disease with albuminuria is on metformin at goal A1c but the clinician wants added renal protection. Which class is preferred for slowing kidney disease progression in this setting?
     • DPP-4 inhibitor
     • Sulfonylurea
     • Meglitinide
     • SGLT2 inhibitor

     Correct answer: SGLT2 inhibitor

     An SGLT2 inhibitor is correct. This class slows progression of diabetic kidney disease and reduces albuminuria and cardiovascular and heart-failure events, making it the preferred add-on for diabetic patients with chronic kidney disease and albuminuria. DPP-4 inhibitors, sulfonylureas, and meglitinides lower glucose but lack the demonstrated kidney-protective benefit of SGLT2 inhibitors.

312. A 50-year-old with newly diagnosed type 2 diabetes asks about preventing eye complications. At what point after diagnosis of type 2 diabetes should the first dilated retinal eye examination be performed?
     • Five years after diagnosis
     • Only when visual symptoms develop
     • Ten years after diagnosis
     • At the time of diagnosis

     Correct answer: At the time of diagnosis

     At the time of diagnosis is correct. Because type 2 diabetes is often present for years before recognition, retinopathy may already exist, so a dilated comprehensive eye examination is recommended at the time of diagnosis and then periodically thereafter. Waiting five or ten years, or until symptoms appear, would miss treatable early retinopathy. Type 1 diabetes, by contrast, allows a delay before the first screening.

313. A 28-year-old with type 1 diabetes on insulin develops sweating, tremor, palpitations, and confusion two hours after a missed meal; a fingerstick reads 42 mg/dL. After giving fast-acting oral carbohydrate, which step best prevents recurrence in the next few hours?
     • Administer an additional dose of rapid-acting insulin
     • Recheck glucose and provide a longer-acting carbohydrate or meal once recovered
     • Encourage vigorous exercise to use up circulating insulin
     • Withhold all further food until the next scheduled meal

     Correct answer: Recheck glucose and provide a longer-acting carbohydrate or meal once recovered

     Rechecking glucose and providing a longer-acting carbohydrate or meal once recovered is correct. After treating acute hypoglycemia with fast-acting carbohydrate, glucose should be rechecked and a more sustained carbohydrate source or meal given to prevent rebound hypoglycemia while injected insulin remains active. Giving more insulin or exercising would deepen hypoglycemia, and withholding food risks recurrence.

314. A pregnant patient at 26 weeks gestation undergoes screening and has a 1-hour 50-gram glucose challenge of 165 mg/dL, prompting a confirmatory test. Which condition is being evaluated, and what is the next step?
     • Type 1 diabetes, confirmed with islet autoantibodies
     • Overt diabetes, requiring no further testing
     • Gestational diabetes, confirmed with a follow-up oral glucose tolerance test
     • Hypoglycemia of pregnancy, requiring glucagon

     Correct answer: Gestational diabetes, confirmed with a follow-up oral glucose tolerance test

     Gestational diabetes, confirmed with a follow-up oral glucose tolerance test is correct. An elevated 1-hour 50-gram glucose challenge during the 24-to-28-week screening window is a screen for gestational diabetes; an abnormal result is confirmed with a diagnostic oral glucose tolerance test rather than diagnosed outright. Islet autoantibody testing and glucagon are not part of routine gestational diabetes screening.

315. A 30-year-old with type 1 diabetes was diagnosed in childhood. By what mechanism does this form of diabetes most fundamentally differ from type 2 diabetes?
     • Peripheral tissue insulin resistance with relative insulin excess
     • Excess glucagon secretion from an alpha-cell tumor
     • Autoimmune destruction of pancreatic beta cells causing absolute insulin deficiency
     • Renal glucose wasting from a tubular transport defect

     Correct answer: Autoimmune destruction of pancreatic beta cells causing absolute insulin deficiency

     Autoimmune destruction of pancreatic beta cells causing absolute insulin deficiency is correct. Type 1 diabetes results from immune-mediated loss of insulin-producing beta cells, leaving patients dependent on exogenous insulin. Type 2 diabetes is characterized by insulin resistance with relatively preserved or excess insulin early on, which is the key distinction. Alpha-cell tumors and renal transport defects are not the basis of either common diabetes type.

316. A patient with type 1 diabetes and a recent gastrointestinal illness is admitted with glucose 520 mg/dL, pH 7.10, bicarbonate 9 mEq/L, and large serum ketones. After fluids are started, when should the insulin infusion be initiated relative to the serum potassium?
     • Only after confirming serum potassium is at least 3.3 mEq/L
     • Immediately, regardless of potassium
     • Only after potassium exceeds 6.0 mEq/L
     • Insulin should be withheld until the anion gap closes

     Correct answer: Only after confirming serum potassium is at least 3.3 mEq/L

     Only after confirming serum potassium is at least 3.3 mEq/L is correct. Because insulin drives potassium into cells, starting insulin when potassium is already low can precipitate life-threatening hypokalemia and arrhythmia, so insulin is held and potassium replaced first if the level is below roughly 3.3 mEq/L. Insulin is needed to close the anion gap, so withholding it until the gap closes is self-defeating.

317. A patient being treated for diabetic ketoacidosis with an insulin infusion has glucose falling steadily, but the anion gap remains elevated and serum bicarbonate is still low. Which adjustment is most appropriate?
     • Stop the insulin infusion because glucose is improving
     • Switch to subcutaneous insulin immediately
     • Administer a bolus of sodium bicarbonate to correct the gap
     • Continue the insulin infusion and add dextrose to fluids to keep treating the ketoacidosis

     Correct answer: Continue the insulin infusion and add dextrose to fluids to keep treating the ketoacidosis

     Continuing the insulin infusion and adding dextrose to fluids is correct. The therapeutic endpoint in diabetic ketoacidosis is closure of the anion gap and resolution of acidosis, not merely a normal glucose, so insulin must continue with dextrose added once glucose falls to keep clearing ketones safely. Stopping insulin or transitioning to subcutaneous therapy prematurely allows ketogenesis to resume, and routine bicarbonate is not indicated.

318. Which arterial blood gas and serum pattern is characteristic of diabetic ketoacidosis?
     • Metabolic alkalosis with compensatory hypoventilation
     • Normal anion gap metabolic acidosis without ketones
     • High anion gap metabolic acidosis with respiratory compensation
     • Respiratory acidosis from hypoventilation

     Correct answer: High anion gap metabolic acidosis with respiratory compensation

     High anion gap metabolic acidosis with respiratory compensation is correct. Accumulation of ketoacids in diabetic ketoacidosis produces an elevated anion gap metabolic acidosis, and the body compensates with rapid deep Kussmaul breathing to blow off carbon dioxide. A metabolic alkalosis or a normal anion gap without ketones does not fit, and the acidosis is metabolic rather than respiratory in origin.

319. Which serum measurement most directly reflects the predominant ketone body produced in diabetic ketoacidosis and is the preferred marker for tracking response to therapy?
     • Serum lactate
     • Beta-hydroxybutyrate
     • Serum acetone by smell
     • Urine specific gravity

     Correct answer: Beta-hydroxybutyrate

     Beta-hydroxybutyrate is correct. It is the dominant ketone body in diabetic ketoacidosis, and measuring it directly provides a more accurate gauge of ketosis and treatment response than the nitroprusside reaction, which detects acetoacetate. Serum lactate reflects a different acidosis, qualitative acetone smell is unreliable, and urine specific gravity assesses hydration rather than ketosis.

320. A patient newly started on a sodium-glucose cotransporter-2 inhibitor presents with nausea, malaise, and a high anion gap acidosis with ketones, yet blood glucose is only 185 mg/dL. Which complication should be suspected?
     • Hyperosmolar hyperglycemic state
     • Lactic acidosis from metformin
     • Euglycemic diabetic ketoacidosis
     • Hypoglycemia

     Correct answer: Euglycemic diabetic ketoacidosis

     Euglycemic diabetic ketoacidosis is correct. SGLT2 inhibitors can precipitate ketoacidosis with only mildly elevated or near-normal glucose because urinary glucose loss lowers the blood glucose while ketogenesis proceeds, so a normal glucose does not exclude the diagnosis. Hyperosmolar hyperglycemic state requires very high glucose with minimal ketosis, and the ketosis here distinguishes it from simple hypoglycemia or lactic acidosis.

321. A 45-year-old woman with newly diagnosed primary hypothyroidism reports tiredness but has no cardiac disease. Which approach to starting levothyroxine is most appropriate for a typical otherwise-healthy adult?
     • Begin a high suppressive dose to normalize symptoms within days
     • Begin a full weight-based replacement dose and titrate to TSH
     • Avoid treatment until free T4 falls below half of normal
     • Start with liothyronine alone as first-line therapy

     Correct answer: Begin a full weight-based replacement dose and titrate to TSH

     Beginning a full weight-based replacement dose and titrating to TSH is correct. In a young or middle-aged adult without cardiac disease, levothyroxine can be initiated at an estimated full replacement dose and then adjusted based on TSH measured after steady state. Suppressive dosing risks iatrogenic hyperthyroidism, delaying treatment is inappropriate, and levothyroxine rather than liothyronine alone is the standard agent.

322. An elderly patient with longstanding coronary artery disease is found to have overt primary hypothyroidism. How should levothyroxine be initiated in this patient?
     • Start at full weight-based replacement immediately
     • Start at a low dose and titrate up slowly
     • Use a high loading dose to rapidly restore euthyroidism
     • Withhold therapy because treatment is contraindicated in heart disease

     Correct answer: Start at a low dose and titrate up slowly

     Starting at a low dose and titrating up slowly is correct. In older patients or those with cardiac disease, levothyroxine is begun at a reduced dose and increased gradually because rapidly raising thyroid hormone can increase myocardial oxygen demand and precipitate angina or arrhythmia. A full or loading dose risks cardiac events, and hypothyroidism still requires treatment, just cautiously.

323. A patient with stable hypothyroidism on a steady levothyroxine dose has a TSH of 0.05 mIU/L with a free T4 at the upper limit of normal and reports palpitations. Which action is most appropriate?
     • Increase the levothyroxine dose
     • Add liothyronine to the regimen
     • Decrease the levothyroxine dose
     • Continue the same dose without change

     Correct answer: Decrease the levothyroxine dose

     Decreasing the levothyroxine dose is correct. A suppressed TSH indicates over-replacement, which carries risks such as atrial fibrillation and bone loss, so the dose should be reduced to bring TSH back into the target range. Increasing the dose or adding liothyronine would worsen the iatrogenic thyrotoxicosis, and continuing unchanged ignores the suppressed TSH and symptoms.

324. A 34-year-old woman planning pregnancy has known hypothyroidism on levothyroxine. What change in thyroid hormone requirement should be anticipated once she becomes pregnant?
     • Levothyroxine should be discontinued during pregnancy
     • Levothyroxine requirements typically decrease sharply
     • The dose should be unchanged throughout gestation
     • Levothyroxine requirements typically increase

     Correct answer: Levothyroxine requirements typically increase

     Levothyroxine requirements typically increase is correct. Pregnancy raises thyroid-binding globulin and metabolic demand, so most hypothyroid patients need a higher levothyroxine dose, often early in gestation, with close TSH monitoring to protect fetal neurodevelopment. Discontinuing therapy or lowering the dose would cause maternal and fetal harm, and leaving the dose unchanged usually leads to under-replacement.

325. A patient with Hashimoto thyroiditis has a diffusely enlarged, firm, nontender thyroid. Which long-term thyroid functional outcome is most characteristic of this autoimmune disease?
     • Sustained hyperthyroidism
     • Permanent euthyroid goiter without dysfunction
     • Recurrent thyroid storm
     • Progressive hypothyroidism

     Correct answer: Progressive hypothyroidism

     Progressive hypothyroidism is correct. Hashimoto thyroiditis causes chronic lymphocytic destruction of the thyroid, and although there may be transient early hormone release, the disease typically progresses to hypothyroidism requiring replacement. Sustained hyperthyroidism is the picture of Graves disease, and thyroid storm is a hyperthyroid emergency, not a feature of Hashimoto.

326. A 36-year-old woman with Graves disease wants a definitive, non-surgical treatment and has no significant eye disease and is not pregnant or breastfeeding. Which therapy provides durable cure by ablating the overactive gland?
     • Long-term low-dose aspirin
     • Lifelong propranolol alone
     • Radioactive iodine ablation
     • Levothyroxine supplementation

     Correct answer: Radioactive iodine ablation

     Radioactive iodine ablation is correct. It destroys overactive thyroid tissue and offers a durable, definitive non-surgical cure for Graves disease in appropriate candidates, usually resulting in hypothyroidism that is then managed with levothyroxine. Propranolol only controls symptoms, aspirin has no role, and levothyroxine would add hormone to an already hyperthyroid patient.

327. A patient on methimazole for Graves disease calls reporting fever and a severe sore throat. Which immediate action is most appropriate?
     • Double the methimazole dose to control symptoms
     • Stop methimazole and obtain a complete blood count to evaluate for agranulocytosis
     • Reassure the patient that this is an expected drug effect
     • Add propylthiouracil to the methimazole

     Correct answer: Stop methimazole and obtain a complete blood count to evaluate for agranulocytosis

     Stopping methimazole and obtaining a complete blood count to evaluate for agranulocytosis is correct. Thionamides can cause agranulocytosis, and fever with sore throat is the classic warning sign, so the drug must be held and the white count checked urgently. Increasing the dose or adding another thionamide could worsen marrow suppression, and dismissing the symptom is dangerous.

328. A patient with hyperthyroidism has a low radioactive iodine uptake scan, an elevated free T4, and no thyroid tenderness, and admits to taking thyroid hormone pills to lose weight. Which diagnosis best explains this picture?
     • Graves disease
     • Toxic multinodular goiter
     • Factitious thyrotoxicosis from exogenous hormone
     • Toxic adenoma

     Correct answer: Factitious thyrotoxicosis from exogenous hormone

     Factitious thyrotoxicosis from exogenous hormone is correct. Ingesting thyroid hormone suppresses endogenous production and gland activity, producing hyperthyroid labs with a low radioactive iodine uptake and a nontender gland, and a low serum thyroglobulin would help confirm it. Graves disease, toxic multinodular goiter, and toxic adenoma all show increased uptake because the gland itself is overproducing hormone.

329. An older patient with new atrial fibrillation, weight loss, and minimal classic adrenergic symptoms is found to have a suppressed TSH and elevated free T4. Which presentation does this best illustrate?
     • Subclinical hypothyroidism
     • Apathetic hyperthyroidism in an older adult
     • Euthyroid sick syndrome
     • Myxedema coma

     Correct answer: Apathetic hyperthyroidism in an older adult

     Apathetic hyperthyroidism in an older adult is correct. Elderly patients with hyperthyroidism may lack the typical hyperadrenergic features and instead present with weight loss, atrial fibrillation, fatigue, or depression, a pattern called apathetic hyperthyroidism, while labs still show suppressed TSH and elevated free T4. Subclinical hypothyroidism and myxedema coma are hypothyroid states, which do not fit these labs.

330. A patient with confirmed cortisol excess undergoes a low-dose dexamethasone suppression test. Which result is consistent with Cushing syndrome?
     • Complete suppression of cortisol to undetectable levels
     • A marked rise in ACTH after dexamethasone
     • Failure of morning cortisol to suppress after dexamethasone
     • A normal cortisol diurnal rhythm

     Correct answer: Failure of morning cortisol to suppress after dexamethasone

     Failure of morning cortisol to suppress after dexamethasone is correct. In Cushing syndrome the hypothalamic-pituitary-adrenal axis is no longer normally suppressible, so low-dose dexamethasone fails to lower cortisol the way it would in a healthy person. Full suppression and a preserved diurnal rhythm are normal findings that argue against Cushing syndrome.

331. After confirming cortisol excess, testing shows an elevated plasma ACTH level. Which step best distinguishes a pituitary source from an ectopic source of ACTH?
     • A 24-hour urinary free cortisol measurement
     • A morning random serum cortisol
     • High-dose dexamethasone suppression and pituitary MRI, with inferior petrosal sinus sampling if needed
     • An oral glucose tolerance test

     Correct answer: High-dose dexamethasone suppression and pituitary MRI, with inferior petrosal sinus sampling if needed

     High-dose dexamethasone suppression and pituitary MRI, with inferior petrosal sinus sampling if needed, is correct. Once Cushing syndrome is ACTH-dependent, distinguishing a pituitary adenoma from an ectopic ACTH-secreting tumor relies on high-dose dexamethasone response, pituitary imaging, and confirmatory petrosal sinus sampling. Urinary free cortisol and random cortisol confirm hypercortisolism but do not localize the source, and glucose tolerance testing is unrelated.

332. A patient with Cushing disease from a pituitary ACTH-secreting microadenoma is referred for definitive treatment. Which intervention is the first-line therapy?
     • Bilateral adrenalectomy
     • Radioactive iodine ablation
     • Lifelong high-dose dexamethasone
     • Transsphenoidal resection of the pituitary adenoma

     Correct answer: Transsphenoidal resection of the pituitary adenoma

     Transsphenoidal resection of the pituitary adenoma is correct. For Cushing disease caused by a pituitary ACTH-secreting tumor, selective transsphenoidal surgery to remove the adenoma is the preferred first-line definitive treatment. Bilateral adrenalectomy is a later option that leaves the pituitary tumor in place, radioactive iodine treats thyroid disease, and ongoing dexamethasone would add to glucocorticoid excess.

333. Beyond central obesity and striae, which metabolic complication is commonly seen in Cushing syndrome because of cortisol-driven gluconeogenesis and insulin resistance?
     • Hyperglycemia or new-onset diabetes
     • Persistent hypoglycemia
     • Hyperkalemia
     • Hypocalcemia with tetany

     Correct answer: Hyperglycemia or new-onset diabetes

     Hyperglycemia or new-onset diabetes is correct. Excess cortisol increases hepatic gluconeogenesis and promotes insulin resistance, frequently causing impaired glucose tolerance or overt diabetes in Cushing syndrome. The disorder tends to cause hypokalemia rather than hyperkalemia and does not characteristically produce hypoglycemia or hypocalcemic tetany.

334. A patient on long-term high-dose prednisone for an autoimmune disease must stop the medication. Which approach minimizes the risk of precipitating adrenal insufficiency?
     • Stop the corticosteroid abruptly to speed recovery
     • Taper the corticosteroid gradually to allow recovery of the adrenal axis
     • Replace it immediately with an equivalent dose of levothyroxine
     • Switch to an SGLT2 inhibitor before stopping

     Correct answer: Taper the corticosteroid gradually to allow recovery of the adrenal axis

     Tapering the corticosteroid gradually is correct. Prolonged exogenous glucocorticoids suppress the hypothalamic-pituitary-adrenal axis, so abrupt withdrawal can cause secondary adrenal insufficiency; a slow taper lets endogenous cortisol production recover. Stopping abruptly risks adrenal crisis, and neither levothyroxine nor an SGLT2 inhibitor addresses the suppressed cortisol axis.

335. A patient with confirmed primary adrenal insufficiency is being placed on chronic replacement. Which combination of hormones is typically required?
     • A glucocorticoid alone
     • A glucocorticoid plus a mineralocorticoid
     • A mineralocorticoid alone
     • Thyroid hormone plus insulin

     Correct answer: A glucocorticoid plus a mineralocorticoid

     A glucocorticoid plus a mineralocorticoid is correct. Primary adrenal insufficiency impairs production of both cortisol and aldosterone, so replacement usually combines a glucocorticoid such as hydrocortisone with a mineralocorticoid such as fludrocortisone. Glucocorticoid alone may suffice in secondary adrenal insufficiency but not primary, and thyroid hormone with insulin treats unrelated endocrine disorders.

336. A patient has fatigue and low morning cortisol, but unlike primary adrenal insufficiency has no hyperpigmentation and a normal serum potassium. Which feature most strongly suggests a secondary (pituitary) rather than primary cause?
     • Markedly elevated ACTH
     • Hyperkalemia with hyponatremia
     • Skin and mucosal hyperpigmentation
     • Low or inappropriately normal ACTH with preserved aldosterone

     Correct answer: Low or inappropriately normal ACTH with preserved aldosterone

     Low or inappropriately normal ACTH with preserved aldosterone is correct. In secondary adrenal insufficiency the pituitary fails to produce ACTH, so ACTH is low and the renin-angiotensin-driven aldosterone system is intact, sparing potassium balance and avoiding hyperpigmentation. Elevated ACTH, hyperkalemia, and hyperpigmentation are hallmarks of primary adrenal failure instead.

337. What is the most common cause of primary adrenal insufficiency in developed countries?
     • Tuberculous destruction of the adrenal glands
     • Metastatic cancer to the adrenals
     • Bilateral adrenal hemorrhage
     • Autoimmune adrenalitis

     Correct answer: Autoimmune adrenalitis

     Autoimmune adrenalitis is correct. In resource-rich countries, autoimmune destruction of the adrenal cortex is by far the most common cause of Addison disease, sometimes occurring as part of an autoimmune polyglandular syndrome. Tuberculosis remains a leading cause worldwide but not in developed nations, and metastatic cancer or adrenal hemorrhage are comparatively uncommon causes.

338. A 48-year-old with poorly controlled hypertension is found to have spontaneous hypokalemia and metabolic alkalosis. Screening shows an elevated aldosterone-to-renin ratio. Which endocrine disorder is most likely?
     • Addison disease
     • Cushing disease
     • Primary hyperaldosteronism
     • Diabetes insipidus

     Correct answer: Primary hyperaldosteronism

     Primary hyperaldosteronism is correct. Autonomous aldosterone excess causes resistant hypertension with hypokalemia and metabolic alkalosis, and a high aldosterone-to-renin ratio is the standard screening finding. Addison disease causes hyperkalemia and hypotension, the opposite picture, while Cushing disease and diabetes insipidus do not produce this specific aldosterone-renin pattern.

339. A 42-year-old with episodic severe headaches, palpitations, drenching sweats, and paroxysmal hypertension is suspected of having a catecholamine-secreting tumor. Which initial biochemical test best screens for pheochromocytoma?
     • A single random serum cortisol
     • Serum TSH
     • Fasting lipid panel
     • Plasma free metanephrines or 24-hour urinary fractionated metanephrines

     Correct answer: Plasma free metanephrines or 24-hour urinary fractionated metanephrines

     Plasma free metanephrines or 24-hour urinary fractionated metanephrines is correct. Pheochromocytoma secretes catecholamines that are metabolized to metanephrines, so measuring fractionated metanephrines provides the most sensitive biochemical screen. Cortisol screens for adrenal cortisol disorders, TSH for thyroid disease, and a lipid panel for cardiovascular risk, none of which detect catecholamine excess.

340. A patient is scheduled for surgical removal of a confirmed pheochromocytoma. Which preoperative pharmacologic preparation is essential to prevent intraoperative hypertensive crisis?
     • Alpha-adrenergic blockade started before any beta-blockade
     • Beta-blockade alone started first
     • Immediate high-dose diuretic therapy
     • Initiation of insulin infusion

     Correct answer: Alpha-adrenergic blockade started before any beta-blockade

     Alpha-adrenergic blockade started before any beta-blockade is correct. Patients with pheochromocytoma require alpha-blockade first to control catecholamine-driven vasoconstriction; beta-blockade alone before adequate alpha-blockade can cause unopposed alpha stimulation and a hypertensive crisis. Diuretics and insulin do not address the catecholamine-mediated vasoconstriction that threatens surgery.

341. A 60-year-old has fatigue, constipation, kidney stones, and bone pain. Labs reveal an elevated serum calcium with an inappropriately high parathyroid hormone level. Which diagnosis best fits?
     • Hypoparathyroidism
     • Vitamin D toxicity
     • Primary hyperparathyroidism
     • Secondary hyperparathyroidism from kidney disease

     Correct answer: Primary hyperparathyroidism

     Primary hyperparathyroidism is correct. Autonomous parathyroid hormone secretion, usually from a parathyroid adenoma, raises serum calcium while parathyroid hormone remains inappropriately elevated, producing the classic stones, bones, and abdominal-and-fatigue symptom complex. Hypoparathyroidism causes low calcium, vitamin D toxicity raises calcium but suppresses parathyroid hormone, and secondary hyperparathyroidism is driven by low calcium from renal disease.

342. A patient develops perioral numbness, tingling in the fingers, and carpopedal spasm shortly after total thyroidectomy. Which acute electrolyte disturbance is most likely responsible?
     • Hypocalcemia from injury to the parathyroid glands
     • Hyperkalemia
     • Hypernatremia
     • Hypermagnesemia

     Correct answer: Hypocalcemia from injury to the parathyroid glands

     Hypocalcemia from injury to the parathyroid glands is correct. Thyroid surgery can damage or remove the adjacent parathyroid glands, causing acute hypocalcemia that presents with perioral and digital paresthesias and neuromuscular irritability such as carpopedal spasm. Hyperkalemia, hypernatremia, and hypermagnesemia do not produce this characteristic postoperative tetany picture.

343. A 45-year-old reports excessive thirst and passing large volumes of dilute urine. Labs show high serum sodium, high serum osmolality, and inappropriately dilute urine, and symptoms improve after administering desmopressin. Which diagnosis is most consistent?
     • Syndrome of inappropriate antidiuretic hormone
     • Primary polydipsia
     • Nephrogenic diabetes insipidus
     • Central diabetes insipidus

     Correct answer: Central diabetes insipidus

     Central diabetes insipidus is correct. Deficient antidiuretic hormone causes loss of large volumes of dilute urine with rising serum sodium and osmolality, and the urine concentrates in response to exogenous desmopressin, confirming a central cause. Nephrogenic diabetes insipidus would not respond to desmopressin, the syndrome of inappropriate antidiuretic hormone causes low sodium, and primary polydipsia features low rather than high serum sodium.

344. A 32-year-old woman with amenorrhea and milky nipple discharge unrelated to nursing is found to have an elevated prolactin level and a pituitary mass on imaging. Which initial treatment is preferred for a symptomatic prolactinoma?
     • A dopamine agonist such as cabergoline
     • Immediate transsphenoidal surgery as first-line therapy
     • Levothyroxine
     • Radioactive iodine

     Correct answer: A dopamine agonist such as cabergoline

     A dopamine agonist such as cabergoline is correct. Prolactinomas usually respond well to dopamine agonists, which lower prolactin, restore menses and fertility, and shrink the tumor, making them first-line over surgery in most cases. Surgery is reserved for refractory or complicated tumors, and levothyroxine and radioactive iodine treat thyroid disorders, not a prolactin-secreting pituitary tumor.

345. A 52-year-old reports enlarging hands and feet, a coarsening face, and rings that no longer fit. Which initial laboratory test best screens for acromegaly?
     • Serum insulin-like growth factor 1 (IGF-1)
     • A random growth hormone level
     • Serum TSH
     • Morning cortisol

     Correct answer: Serum insulin-like growth factor 1 (IGF-1)

     Serum insulin-like growth factor 1 (IGF-1) is correct. Because growth hormone is secreted in pulses, a random growth hormone level is unreliable, so IGF-1, which integrates growth hormone activity over time, is the preferred screening test for acromegaly and is confirmed with an oral glucose tolerance test showing failure of growth hormone to suppress. TSH and cortisol assess unrelated axes.

346. A patient with a confirmed solitary thyroid nodule has a suppressed TSH. Which is the most appropriate next step before considering fine-needle aspiration?
     • Immediate total thyroidectomy
     • A radioactive iodine uptake scan to evaluate for an autonomous functioning nodule
     • Empiric levothyroxine to shrink the nodule
     • Starting methimazole without further workup

     Correct answer: A radioactive iodine uptake scan to evaluate for an autonomous functioning nodule

     A radioactive iodine uptake scan is correct. When a thyroid nodule is accompanied by a low TSH, a radionuclide scan is performed first because a hyperfunctioning hot nodule is rarely malignant and is managed differently, often sparing the patient an unnecessary biopsy. Proceeding directly to surgery, empiric levothyroxine, or methimazole skips this essential functional assessment.

347. A patient with type 2 diabetes started on a sulfonylurea is at increased risk of which common adverse effect compared with metformin?
     • Lactic acidosis
     • Hypoglycemia
     • Genital mycotic infections
     • Pancreatitis

     Correct answer: Hypoglycemia

     Hypoglycemia is correct. Sulfonylureas stimulate insulin secretion regardless of the current glucose level, so they carry a meaningfully higher risk of hypoglycemia than metformin, which does not directly raise insulin secretion. Lactic acidosis is a rare metformin concern, genital mycotic infections are associated with SGLT2 inhibitors, and pancreatitis is more linked to incretin-based therapies.

348. A patient with type 2 diabetes has had progressive beta-cell decline and very high glucose with marked symptoms despite multiple oral agents. Which therapy is now most appropriate to control the severe hyperglycemia?
     • Adding a second sulfonylurea
     • Initiating insulin therapy
     • Stopping all medications and reassessing in a year
     • Switching to an alpha-glucosidase inhibitor alone

     Correct answer: Initiating insulin therapy

     Initiating insulin therapy is correct. When oral and non-insulin agents fail to control marked, symptomatic hyperglycemia, insulin is the most effective and appropriate next step to lower glucose and relieve symptoms. Stacking sulfonylureas adds hypoglycemia risk without adequate efficacy, stopping all therapy is unsafe, and an alpha-glucosidase inhibitor alone is too weak for severe hyperglycemia.

349. For most nonpregnant adults with type 2 diabetes, which HbA1c goal is generally recommended as a reasonable glycemic target when it can be achieved safely?
     • Less than 7%
     • Less than 5%
     • Less than 9%
     • Less than 10%

     Correct answer: Less than 7%

     Less than 7% is correct. A general HbA1c target of under 7% balances reduction of microvascular complications against hypoglycemia risk for most nonpregnant adults, with individualization toward tighter or looser goals based on age, comorbidities, and life expectancy. A goal under 5% is unnecessarily aggressive and unsafe, while targets of 9% or 10% allow excessive chronic hyperglycemia.

350. A patient with type 2 diabetes asks whether their feet need special attention. How often should a comprehensive foot examination assessing protective sensation and vascular status generally be performed in diabetes?
     • At least annually
     • Only if an ulcer develops
     • Once at diagnosis and never again
     • Every five years

     Correct answer: At least annually

     At least annually is correct. Patients with diabetes should have a comprehensive foot examination at least once a year to detect loss of protective sensation, deformity, and vascular compromise that predispose to ulceration and amputation, with more frequent checks for high-risk feet. Waiting for an ulcer, examining only at diagnosis, or every five years would miss preventable complications.

351. A patient with hyperthyroidism from Graves disease has moderate active eye disease with proptosis and diplopia. Which definitive therapy is generally avoided because it can worsen the orbitopathy?
     • Methimazole
     • Beta-blocker therapy
     • Thyroidectomy
     • Radioactive iodine ablation

     Correct answer: Radioactive iodine ablation

     Radioactive iodine ablation is correct. In Graves disease with active moderate-to-severe eye disease, radioactive iodine can transiently worsen the orbitopathy, so antithyroid medication or surgery is generally preferred and corticosteroid prophylaxis is considered if iodine is used. Methimazole, beta-blockers, and thyroidectomy do not carry the same risk of exacerbating eye disease.

352. A 3-year-old has had ear pain and fever for two days. On otoscopy the tympanic membrane is bulging and erythematous with loss of the normal landmarks, and pneumatic insufflation shows markedly reduced movement. Which combination of findings is required to diagnose acute otitis media?
     • Moderate-to-severe bulging of the tympanic membrane with signs of middle-ear effusion
     • Cerumen impaction plus ear canal tenderness on tragal pressure
     • A perforated drum with chronic foul-smelling drainage
     • A pearly gray membrane with a sharp light reflex and full mobility

     Correct answer: Moderate-to-severe bulging of the tympanic membrane with signs of middle-ear effusion

     Moderate-to-severe bulging of the tympanic membrane with signs of middle-ear effusion is the answer because the diagnosis of acute otitis media requires evidence of a middle-ear effusion together with acute inflammation, and bulging is the single most reliable predictor. Cerumen impaction with tragal tenderness suggests otitis externa, a perforated drum with chronic drainage indicates chronic suppurative otitis media, and a pearly mobile membrane with a sharp light reflex is normal.

353. A clinician opts for watchful waiting in a 3-year-old with mild, unilateral acute otitis media and reliable follow-up. If symptoms have not improved, after approximately how long should antibiotics be started?
     • After 24 hours
     • After 48 to 72 hours
     • After 10 days
     • After 2 weeks

     Correct answer: After 48 to 72 hours

     After 48 to 72 hours is the answer because the observation option for selected children with acute otitis media allows roughly two to three days for spontaneous improvement before antibiotics are initiated if the child fails to get better. Waiting only 24 hours is too short to distinguish self-resolution from true failure, and waiting 10 days or 2 weeks would dangerously prolong an untreated bacterial infection.

354. A 5-year-old with acute otitis media completed high-dose amoxicillin but still has fever and a bulging drum after 3 days. Which oral agent is the recommended next step for treatment failure?
     • Azithromycin
     • Trimethoprim-sulfamethoxazole
     • Amoxicillin-clavulanate
     • Cephalexin

     Correct answer: Amoxicillin-clavulanate

     Amoxicillin-clavulanate is the answer because adding a beta-lactamase inhibitor covers resistant Haemophilus influenzae and Moraxella catarrhalis that commonly cause amoxicillin failure in acute otitis media. Azithromycin and trimethoprim-sulfamethoxazole have unreliable pneumococcal activity, and cephalexin is a first-generation cephalosporin with poor coverage of the typical otitis pathogens.

355. A swimmer presents with an itchy, painful ear and pain when the auricle is pulled. The canal is edematous and erythematous with debris, but the tympanic membrane, where visible, is normal. Which diagnosis best fits and how does it differ from acute otitis media?
     • Acute otitis media, because canal swelling reflects middle-ear pus
     • Mastoiditis, because tragal pain indicates bony involvement
     • Cholesteatoma, because debris is always keratin
     • Otitis externa, which involves the external canal rather than the middle ear

     Correct answer: Otitis externa, which involves the external canal rather than the middle ear

     Otitis externa is the answer because pain on manipulating the auricle or tragus with a swollen, debris-filled external canal and a normal drum localizes the disease to the ear canal, not the middle ear. Acute otitis media produces a bulging or immobile drum without canal tenderness, mastoiditis causes postauricular swelling and tenderness, and cholesteatoma is a chronic keratin mass rather than acute canal inflammation.

356. A child with untreated acute otitis media now has fever, postauricular swelling and tenderness, and an auricle that is pushed forward and outward. Which complication should be suspected?
     • Acute mastoiditis
     • Otitis media with effusion
     • Allergic rhinitis
     • Eustachian tube dysfunction

     Correct answer: Acute mastoiditis

     Acute mastoiditis is the answer because postauricular swelling, tenderness, and protrusion of the auricle in a child with otitis media indicate infection extending into the mastoid air cells, requiring urgent imaging and intravenous antibiotics. Otitis media with effusion is a painless noninfected fluid collection, while allergic rhinitis and eustachian tube dysfunction do not cause postauricular inflammation or auricular displacement.

357. A 6-year-old has had middle-ear fluid documented for four months following an episode of acute otitis media, with hearing testing showing a conductive loss that is interfering with school performance. Which step is most appropriate?
     • A six-week course of oral antibiotics
     • Referral for tympanostomy tube placement
     • Long-term oral antihistamines
     • Continued watchful waiting for another six months

     Correct answer: Referral for tympanostomy tube placement

     Referral for tympanostomy tube placement is the answer because persistent otitis media with effusion lasting three months or more with documented hearing loss and functional impact is an indication for ventilation tubes. Prolonged antibiotics and antihistamines do not clear chronic effusions, and further watchful waiting would allow ongoing hearing loss to harm speech and learning.

358. A 22-year-old has a red eye with thin watery discharge, a gritty foreign-body sensation, and a palpable tender preauricular node. A roommate had identical symptoms last week. Which feature most specifically distinguishes this viral conjunctivitis from a bacterial cause?
     • Bilateral conjunctival redness
     • Mild itching of the eyes
     • A tender preauricular lymph node
     • Crusting of the eyelids in the morning

     Correct answer: A tender preauricular lymph node

     A tender preauricular lymph node is the answer because preauricular adenopathy is a hallmark of adenoviral conjunctivitis and is rarely present in routine bacterial conjunctivitis. Bilateral redness, mild itching, and morning crusting can occur in several types of conjunctivitis and are not specific enough to separate viral from bacterial disease on their own.

359. Which presentation is most characteristic of bacterial rather than viral or allergic conjunctivitis?
     • Bilateral itching with stringy mucoid discharge
     • Watery discharge with a recent upper respiratory infection
     • A painless red patch over the sclera after coughing
     • Thick mucopurulent discharge that rapidly returns after wiping, with eyelids stuck together on waking

     Correct answer: Thick mucopurulent discharge that rapidly returns after wiping, with eyelids stuck together on waking

     Thick mucopurulent discharge that rapidly returns after wiping with matted lids on waking is the answer because copious purulent discharge is the defining feature of bacterial conjunctivitis. Bilateral itching with stringy discharge indicates allergy, watery discharge after a respiratory infection indicates a viral cause, and a painless scleral red patch after coughing describes a subconjunctival hemorrhage.

360. A 27-year-old soft contact lens wearer presents with a painful, red, photophobic eye and decreased vision. Slit-lamp examination shows a corneal infiltrate with overlying fluorescein uptake. Why does this finding change management compared with routine conjunctivitis?
     • It signals microbial keratitis, a sight-threatening corneal infection requiring urgent ophthalmology referral
     • It is allergic and needs only an antihistamine drop
     • It is a benign viral conjunctivitis that will self-resolve
     • It is ocular surface dryness needing artificial tears only

     Correct answer: It signals microbial keratitis, a sight-threatening corneal infection requiring urgent ophthalmology referral

     Microbial keratitis is the answer because a painful eye with photophobia, reduced vision, and a fluorescein-staining corneal infiltrate in a contact lens wearer indicates corneal infection that can scar and permanently impair vision, demanding urgent specialist care and culture-directed fortified antibiotics. Conjunctivitis spares the cornea, so antihistamines, reassurance, or artificial tears would inappropriately delay treatment.

361. A 19-year-old with known dust and pollen sensitivity has recurrent bilateral itchy, watery eyes with conjunctival swelling. After avoidance measures fail, which topical medication class is preferred for ongoing control?
     • A topical aminoglycoside antibiotic
     • A topical antihistamine and mast cell stabilizer combination
     • A topical prostaglandin analog
     • A topical antiviral such as ganciclovir gel

     Correct answer: A topical antihistamine and mast cell stabilizer combination

     A topical antihistamine and mast cell stabilizer combination is the answer because dual-acting agents both block existing histamine and prevent further mediator release, making them ideal for recurrent allergic conjunctivitis. Topical antibiotics treat bacterial infection, prostaglandin analogs lower intraocular pressure in glaucoma, and antivirals target herpetic eye disease, none of which address an allergic mechanism.

362. A patient with adenoviral conjunctivitis asks how to avoid spreading it. Which counseling point is most appropriate?
     • Antibiotic drops will quickly make it noncontagious
     • It is not contagious and no precautions are needed
     • It is highly contagious; emphasize handwashing and avoid sharing towels for one to two weeks
     • Oral antivirals will eliminate the contagious period

     Correct answer: It is highly contagious; emphasize handwashing and avoid sharing towels for one to two weeks

     Emphasizing handwashing and avoiding shared towels is the answer because adenoviral conjunctivitis is highly contagious through direct and fomite contact, and hygiene measures during the symptomatic period are the mainstay of preventing spread. Antibiotic drops have no effect on a virus, the infection is clearly contagious, and oral antivirals are not used for ordinary adenoviral conjunctivitis.

363. A neonate develops profuse bilateral purulent eye discharge on day 3 of life with marked eyelid swelling. Which causative organism poses the greatest threat of corneal perforation and warrants urgent systemic treatment?
     • Chlamydia trachomatis
     • Adenovirus
     • Staphylococcus epidermidis
     • Neisseria gonorrhoeae

     Correct answer: Neisseria gonorrhoeae

     Neisseria gonorrhoeae is the answer because gonococcal ophthalmia neonatorum produces hyperacute copious purulent discharge within the first days of life and can rapidly invade and perforate the cornea, mandating urgent systemic antibiotics. Chlamydial conjunctivitis typically appears later and is less aggressive, adenovirus is not the classic perforating neonatal pathogen, and Staphylococcus epidermidis is usually a benign commensal.

364. A 70-year-old presents with a severely painful red eye, blurred vision with colored halos around lights, headache, and vomiting. The pupil is mid-dilated and minimally reactive, and the globe feels rock-hard. Which immediate treatment goal is most critical?
     • Rapidly lowering the intraocular pressure
     • Dilating the pupil to relieve the obstruction
     • Starting topical antibiotics for infection
     • Patching the eye and rechecking in 24 hours

     Correct answer: Rapidly lowering the intraocular pressure

     Rapidly lowering the intraocular pressure is the answer because acute angle-closure glaucoma causes a sudden dangerous pressure rise that can destroy the optic nerve within hours, so emergent pressure reduction is the priority before definitive laser iridotomy. Dilating the pupil worsens the angle closure, antibiotics treat infection that is not present, and patching with delayed reassessment would risk permanent vision loss.

365. During a routine eye examination, a 60-year-old is found to have an enlarged optic cup-to-disc ratio and an arcuate defect on visual field testing, with intraocular pressure measured at 26 mmHg. The patient denies any eye pain or redness. Which diagnosis is most consistent?
     • Acute angle-closure glaucoma
     • Primary open-angle glaucoma
     • Cataract
     • Bacterial conjunctivitis

     Correct answer: Primary open-angle glaucoma

     Primary open-angle glaucoma is the answer because painless progressive optic disc cupping, characteristic visual field loss, and elevated intraocular pressure without symptoms define this chronic optic neuropathy. Angle-closure glaucoma presents acutely with pain and a fixed pupil, a cataract clouds the lens without disc cupping or field defects, and bacterial conjunctivitis causes a red eye with discharge rather than optic nerve changes.

366. A patient newly diagnosed with primary open-angle glaucoma is prescribed latanoprost. By what mechanism does this prostaglandin analog lower intraocular pressure?
     • By decreasing aqueous humor production at the ciliary body
     • By constricting the pupil to widen the angle
     • By increasing uveoscleral outflow of aqueous humor
     • By reducing corneal thickness

     Correct answer: By increasing uveoscleral outflow of aqueous humor

     Increasing uveoscleral outflow is the answer because prostaglandin analogs such as latanoprost lower intraocular pressure primarily by enhancing the alternative uveoscleral drainage pathway. Agents that decrease aqueous production are beta-blockers and carbonic anhydrase inhibitors, pupil constriction to open the angle is the action of miotics, and corneal thickness is not a target of glaucoma drops.

367. What is the definitive treatment that addresses the underlying anatomic problem in a patient who has had an episode of acute angle-closure glaucoma?
     • Lifelong topical antibiotics
     • Daily oral antihistamines
     • Surgical lens polishing
     • Laser peripheral iridotomy

     Correct answer: Laser peripheral iridotomy

     Laser peripheral iridotomy is the answer because creating a small hole in the peripheral iris relieves the pupillary block that causes angle closure and prevents recurrent attacks, and it is often performed prophylactically in the fellow eye. Antibiotics and antihistamines do not affect aqueous flow, and lens polishing is not a recognized procedure for angle-closure glaucoma.

368. Which patient characteristic increases the risk of developing acute angle-closure glaucoma?
     • A shallow anterior chamber with a narrow drainage angle
     • Long axial length with myopia
     • Large corneal diameter
     • Low intraocular baseline pressure

     Correct answer: A shallow anterior chamber with a narrow drainage angle

     A shallow anterior chamber with a narrow drainage angle is the answer because crowding of the angle predisposes to sudden obstruction of aqueous outflow, especially when the pupil dilates. Long axial length and myopia are associated with open, deep angles, a large corneal diameter does not narrow the angle, and a low baseline pressure does not predispose to acute closure.

369. A 42-year-old has had nasal congestion, facial pain, and purulent discharge for 11 days with no improvement. Which feature most supports a bacterial rather than viral cause of acute rhinosinusitis?
     • Onset of clear rhinorrhea two days ago
     • Persistent symptoms beyond 10 days without improvement
     • Bilateral sneezing and ocular itching
     • Complete resolution by day 5

     Correct answer: Persistent symptoms beyond 10 days without improvement

     Persistent symptoms beyond 10 days without improvement is the answer because a viral upper respiratory infection typically improves within about 10 days, so symptoms that persist or worsen beyond that window support acute bacterial rhinosinusitis. Recent-onset clear rhinorrhea and prompt resolution suggest a viral process, and bilateral sneezing with itching points to allergic rhinitis.

370. An otherwise healthy 35-year-old with no antibiotic allergy is diagnosed with acute bacterial rhinosinusitis severe enough to warrant treatment. Which first-line antibiotic is recommended?
     • Azithromycin
     • Doxycycline
     • Amoxicillin-clavulanate
     • Cephalexin

     Correct answer: Amoxicillin-clavulanate

     Amoxicillin-clavulanate is the answer because current guidance favors it as first-line therapy for acute bacterial rhinosinusitis, providing coverage of Streptococcus pneumoniae and beta-lactamase-producing Haemophilus influenzae. Macrolides such as azithromycin face high pneumococcal resistance, doxycycline is an alternative reserved for penicillin allergy, and cephalexin lacks adequate respiratory pathogen coverage.

371. A 38-year-old with a few days of sinus pressure, clear nasal discharge, and low-grade symptoms is most appropriately managed with which approach?
     • Immediate broad-spectrum antibiotics
     • Urgent sinus CT scan
     • Empiric antifungal therapy
     • Symptomatic care with analgesics, saline irrigation, and intranasal corticosteroids

     Correct answer: Symptomatic care with analgesics, saline irrigation, and intranasal corticosteroids

     Symptomatic care with analgesics, saline irrigation, and intranasal corticosteroids is the answer because early sinus symptoms with clear discharge reflect viral rhinosinusitis, which is self-limited and managed supportively. Immediate antibiotics are not warranted without features of bacterial disease, routine CT is unnecessary in uncomplicated cases, and antifungals are reserved for invasive fungal sinusitis in immunocompromised patients.

372. A 50-year-old with acute sinusitis develops eyelid swelling, pain with eye movement, and forward displacement of the eye. Which complication must be excluded urgently?
     • Orbital cellulitis from contiguous sinus infection
     • Otitis media with effusion
     • Allergic conjunctivitis
     • Benign positional vertigo

     Correct answer: Orbital cellulitis from contiguous sinus infection

     Orbital cellulitis from contiguous sinus infection is the answer because painful or restricted eye movement, proptosis, and eyelid swelling in a patient with sinusitis indicate spread of infection into the orbit, a vision-threatening emergency requiring urgent imaging and intravenous antibiotics. Otitis media with effusion, allergic conjunctivitis, and positional vertigo do not produce proptosis or painful ophthalmoplegia.

373. Which symptom pattern is the classic double-worsening course that suggests bacterial superinfection of an initially viral sinus illness?
     • Gradual steady improvement over seven days
     • Initial improvement around day 5 to 6 followed by new fever and worsening purulent discharge
     • Symptoms limited to bilateral itchy eyes and sneezing
     • Sudden unilateral foul nasal discharge in a toddler

     Correct answer: Initial improvement around day 5 to 6 followed by new fever and worsening purulent discharge

     Initial improvement followed by renewed fever and worsening discharge is the answer because this double-sickening pattern is a recognized clue to acute bacterial rhinosinusitis complicating a viral course. Steady improvement points to resolving viral illness, itchy eyes with sneezing suggests allergic rhinitis, and unilateral foul discharge in a toddler raises concern for a nasal foreign body.

374. A 16-year-old has sudden sore throat, fever, tender anterior cervical nodes, and tonsillar exudates but no cough. According to the Centor criteria, what is the appropriate next step?
     • Treat empirically without any testing because strep is certain
     • Reassure and provide no testing or treatment
     • Perform a rapid antigen detection test, with throat culture if negative in a child
     • Start a fluoroquinolone immediately

     Correct answer: Perform a rapid antigen detection test, with throat culture if negative in a child

     Performing a rapid antigen detection test with backup culture in a child is the answer because a high Centor score raises suspicion for group A streptococcal pharyngitis but still requires microbiologic confirmation, and children warrant a confirmatory culture when the rapid test is negative. Empiric treatment without testing risks unnecessary antibiotics, no testing misses treatable disease, and fluoroquinolones are not appropriate for pharyngitis.

375. Which of the following findings would subtract from, rather than add to, the Centor score for streptococcal pharyngitis?
     • Tonsillar exudates
     • Tender anterior cervical lymphadenopathy
     • Fever
     • Presence of a cough

     Correct answer: Presence of a cough

     Presence of a cough is the answer because absence of cough is one of the four Centor criteria, so a cough points toward a viral etiology and lowers the calculated probability of strep. Tonsillar exudates, tender anterior cervical adenopathy, and fever are each criteria that add a point and raise the likelihood of group A streptococcal pharyngitis.

376. A 9-year-old with a positive rapid strep test for group A streptococcal pharyngitis has a documented anaphylactic penicillin allergy. Which antibiotic is an appropriate alternative?
     • Azithromycin
     • Cephalexin
     • Amoxicillin
     • Ampicillin

     Correct answer: Azithromycin

     Azithromycin is the answer because a macrolide is an accepted alternative for streptococcal pharyngitis in a patient with severe, anaphylactic penicillin allergy in whom cephalosporins are best avoided. Cephalexin carries a small cross-reactivity risk and is reserved for non-anaphylactic allergy, and amoxicillin and ampicillin are aminopenicillins that are contraindicated in true penicillin allergy.

377. Why is prompt antibiotic treatment of confirmed group A streptococcal pharyngitis important beyond symptom relief?
     • It prevents future viral infections
     • It prevents acute rheumatic fever
     • It cures coexisting allergic rhinitis
     • It eliminates the need for analgesics

     Correct answer: It prevents acute rheumatic fever

     Preventing acute rheumatic fever is the answer because timely antibiotic therapy for group A streptococcal pharyngitis reduces the risk of this serious nonsuppurative complication, in addition to shortening illness and limiting spread. Antibiotics do not prevent unrelated viral infections, do not treat allergic rhinitis, and do not remove the need for symptomatic analgesia.

378. A 16-year-old has pharyngitis with posterior cervical lymphadenopathy, fatigue, and splenomegaly; the rapid strep test is negative and a heterophile antibody test is positive. Which counseling point is most important?
     • Begin amoxicillin to prevent rheumatic fever
     • Resume full athletic activity immediately
     • Avoid contact sports while splenomegaly is present to reduce splenic rupture risk
     • Start prophylactic anticoagulation

     Correct answer: Avoid contact sports while splenomegaly is present to reduce splenic rupture risk

     Avoiding contact sports during splenomegaly is the answer because infectious mononucleosis carries a risk of splenic rupture, so activity restriction is essential while the spleen is enlarged. Amoxicillin is avoided because it can precipitate a rash in mononucleosis, returning to sports immediately endangers the patient, and anticoagulation has no role in this illness.

379. A 60-year-old reports brief episodes of room-spinning vertigo lasting under a minute that are triggered when lying down or rolling over in bed, without hearing loss or tinnitus. Which condition does this most strongly suggest?
     • Meniere disease
     • Vestibular neuritis
     • Cerebellar stroke
     • Benign paroxysmal positional vertigo

     Correct answer: Benign paroxysmal positional vertigo

     Benign paroxysmal positional vertigo is the answer because brief, position-triggered spinning lasting seconds to under a minute without auditory symptoms is the classic picture of displaced otoconia in the semicircular canals. Meniere disease causes longer attacks with hearing loss and tinnitus, vestibular neuritis produces prolonged continuous vertigo, and a cerebellar stroke causes persistent vertigo with additional neurologic deficits.

380. A patient with suspected posterior canal benign paroxysmal positional vertigo undergoes the Dix-Hallpike maneuver. Which nystagmus pattern confirms the diagnosis?
     • Transient upbeating-torsional nystagmus with a brief latency that fatigues on repetition
     • Sustained vertical down-beating nystagmus that does not fatigue
     • Pure horizontal nystagmus unchanged by position
     • No nystagmus despite reproduced vertigo

     Correct answer: Transient upbeating-torsional nystagmus with a brief latency that fatigues on repetition

     Transient upbeating-torsional nystagmus with brief latency that fatigues is the answer because this pattern reflects otoconial movement in the posterior semicircular canal and is diagnostic on Dix-Hallpike testing. Sustained non-fatiguing nystagmus, especially down-beating, suggests a central lesion, position-independent horizontal nystagmus is not the classic posterior canal finding, and vertigo without any nystagmus does not confirm the diagnosis.

381. A 68-year-old presents with acute persistent vertigo. Which combination of findings should raise concern for a central cause and prompt urgent neuroimaging?
     • Fatigable nystagmus and a normal gait
     • Inability to walk unaided, direction-changing nystagmus, and a new severe headache
     • Unilateral tinnitus and ear fullness
     • Brief vertigo only when turning the head in bed

     Correct answer: Inability to walk unaided, direction-changing nystagmus, and a new severe headache

     Inability to walk unaided with direction-changing nystagmus and a new severe headache is the answer because gait instability out of proportion to a peripheral lesion, direction-changing nystagmus, and headache point to a brainstem or cerebellar process such as stroke. Fatigable nystagmus with normal gait, unilateral tinnitus, and brief positional vertigo are reassuring peripheral features.

382. Which intervention is the first-line treatment for posterior canal benign paroxysmal positional vertigo?
     • Chronic daily meclizine
     • Endolymphatic sac decompression surgery
     • The Epley canalith repositioning maneuver
     • A tapering course of oral prednisone

     Correct answer: The Epley canalith repositioning maneuver

     The Epley canalith repositioning maneuver is the answer because it physically relocates displaced otoconia out of the affected semicircular canal and resolves symptoms in most patients without medication. Long-term meclizine only masks symptoms and may impair central compensation, surgery is reserved for refractory Meniere disease, and corticosteroids have no role in this mechanical disorder.

383. A 45-year-old reports recurrent episodes of vertigo lasting hours, accompanied by fluctuating low-frequency hearing loss, tinnitus, and a sensation of ear fullness. Which diagnosis best fits?
     • Benign paroxysmal positional vertigo
     • Vestibular neuritis
     • Acute otitis media
     • Meniere disease

     Correct answer: Meniere disease

     Meniere disease is the answer because the triad of episodic vertigo lasting minutes to hours, fluctuating sensorineural hearing loss, and tinnitus with aural fullness reflects endolymphatic hydrops. Benign paroxysmal positional vertigo causes only brief positional spells without hearing loss, vestibular neuritis lacks auditory symptoms, and acute otitis media causes ear pain and a bulging drum rather than recurrent vertigo with fluctuating hearing.

384. A 71-year-old reports painless, gradually worsening blurry vision over two years with increasing glare from oncoming headlights at night and faded color perception. Which examination finding would best support a cataract?
     • A diminished or absent red reflex
     • A fixed mid-dilated pupil
     • Tonsillar exudates
     • A tender preauricular node

     Correct answer: A diminished or absent red reflex

     A diminished or absent red reflex is the answer because opacification of the crystalline lens blocks the reflected fundus glow, producing a dulled red reflex consistent with the gradual painless visual decline and glare of a cataract. A fixed mid-dilated pupil indicates acute angle-closure glaucoma, while tonsillar exudates and a preauricular node are throat and conjunctival findings unrelated to lens opacity.

385. Which treatment is definitive and curative for a patient whose cataract is causing functional vision impairment?
     • Topical prostaglandin analog drops
     • Phacoemulsification with intraocular lens implantation
     • Oral corticosteroids
     • Stronger reading glasses alone

     Correct answer: Phacoemulsification with intraocular lens implantation

     Phacoemulsification with intraocular lens implantation is the answer because surgically removing the opacified lens and replacing it with an artificial lens is the only definitive way to restore vision lost to a cataract. Prostaglandin drops treat glaucoma, corticosteroids can actually promote cataract formation, and corrective lenses cannot overcome a significantly clouded lens.

386. Which of the following is a recognized risk factor for the development of cataracts?
     • A high-fiber diet
     • Regular use of reading glasses
     • Chronic systemic or ocular corticosteroid use
     • Frequent use of artificial tears

     Correct answer: Chronic systemic or ocular corticosteroid use

     Chronic corticosteroid use is the answer because prolonged steroid exposure is a well-established cause of lens opacification, alongside aging, diabetes, ultraviolet light, and smoking. A high-fiber diet, reading glasses, and artificial tears have no role in cataract formation and are not risk factors.

387. A 64-year-old with diabetes notices that newly developing cataracts have been associated with a faster decline in vision. Which systemic condition is most strongly linked to earlier or accelerated cataract formation?
     • Iron deficiency anemia
     • Allergic rhinitis
     • Gastroesophageal reflux disease
     • Diabetes mellitus

     Correct answer: Diabetes mellitus

     Diabetes mellitus is the answer because chronic hyperglycemia accelerates lens changes and is a major systemic risk factor for earlier cataract development. Iron deficiency anemia, allergic rhinitis, and gastroesophageal reflux disease do not promote lens opacification and are unrelated to cataract risk.

388. A patient with sudden complete obstruction of one nasal passage and unilateral foul-smelling discharge is a young child. Beyond infection, which cause should be specifically considered?
     • A nasal foreign body
     • Allergic rhinitis
     • Primary open-angle glaucoma
     • Benign paroxysmal positional vertigo

     Correct answer: A nasal foreign body

     A nasal foreign body is the answer because unilateral foul-smelling nasal discharge in a young child is classic for a retained object obstructing one nostril and should prompt examination and removal. Allergic rhinitis causes bilateral clear discharge with itching, while glaucoma and positional vertigo are eye and vestibular conditions unrelated to nasal obstruction.

389. A 32-year-old presents with sudden, painless, bright-red blood spreading flat across the white of one eye after a sneezing fit. Vision is normal, the cornea is clear, and there is no discharge. What is the most appropriate management?
     • Topical antibiotic drops for presumed infection
     • Reassurance and observation, as this resolves spontaneously
     • Urgent intraocular pressure-lowering therapy
     • Oral antiviral therapy

     Correct answer: Reassurance and observation, as this resolves spontaneously

     Reassurance and observation is the answer because a painless, well-demarcated subconjunctival hemorrhage with normal vision and no discharge is a benign self-limited rupture of a small conjunctival vessel that clears over one to two weeks. Antibiotics, pressure-lowering therapy, and antivirals address infection, glaucoma, and viral disease respectively, none of which are present here.

390. A 6-month-old with a first episode of mild acute otitis media is irritable but feeding well, with a temperature of 38.3 degrees Celsius. Given the patient's age, which management is recommended?
     • Watchful waiting for 72 hours before antibiotics
     • Topical antibiotic ear drops only
     • Prompt antibiotic therapy because of the young age
     • Oral decongestants in place of antibiotics

     Correct answer: Prompt antibiotic therapy because of the young age

     Prompt antibiotic therapy because of the young age is the answer because children under 6 months with acute otitis media should be treated rather than observed, given their higher risk of complications. Watchful waiting is an option only for selected older children with mild disease, topical drops cannot penetrate an intact drum to treat a middle-ear infection, and decongestants do not treat the infection.

391. A clinician needs to assess tympanic membrane mobility in a child with suspected acute otitis media. Which examination technique provides this information?
     • Tonometry
     • The Dix-Hallpike maneuver
     • Fluorescein staining
     • Pneumatic otoscopy

     Correct answer: Pneumatic otoscopy

     Pneumatic otoscopy is the answer because applying gentle positive and negative pressure while viewing the tympanic membrane reveals reduced mobility, which indicates a middle-ear effusion supporting acute otitis media. Tonometry measures intraocular pressure, the Dix-Hallpike maneuver tests for positional vertigo, and fluorescein staining detects corneal epithelial defects, none of which assess the eardrum.

392. A 28-year-old with a red, painful eye and photophobia is found to have a branching, dendritic corneal ulcer that stains with fluorescein. Which cause should be suspected, and why is empiric topical corticosteroid alone dangerous?
     • Herpes simplex keratitis, because corticosteroids can worsen the infection and corneal damage
     • Allergic conjunctivitis, because steroids worsen allergy
     • Bacterial conjunctivitis, because steroids cure it
     • Subconjunctival hemorrhage, because steroids stop bleeding

     Correct answer: Herpes simplex keratitis, because corticosteroids can worsen the infection and corneal damage

     Herpes simplex keratitis is the answer because a branching dendritic corneal ulcer staining with fluorescein is the hallmark of herpetic eye infection, which requires antiviral therapy and ophthalmology referral, and topical corticosteroids alone can accelerate corneal destruction. This is not allergic or bacterial conjunctivitis, and a subconjunctival hemorrhage is a painless flat patch of blood without a corneal lesion.

393. A 55-year-old has elevated intraocular pressure on screening but a normal optic disc and full visual fields. How should this finding be classified and managed?
     • Established glaucoma requiring immediate surgery
     • Ocular hypertension requiring monitoring and possible treatment to prevent progression
     • A completely normal result needing no follow-up
     • An acute angle-closure emergency

     Correct answer: Ocular hypertension requiring monitoring and possible treatment to prevent progression

     Ocular hypertension requiring monitoring is the answer because elevated intraocular pressure without optic nerve damage or field loss is a recognized risk factor for glaucoma that warrants surveillance and sometimes pressure-lowering treatment. Surgery is reserved for established disease, the finding is abnormal enough to require follow-up, and the absence of acute pain and symptoms excludes an angle-closure emergency.

394. A 33-year-old with seasonal allergic rhinitis has persistent nasal congestion, sneezing, and itchy, watery eyes despite oral antihistamines. Which medication is the most effective single agent for ongoing control of moderate-to-severe allergic rhinitis symptoms?
     • An oral decongestant taken daily
     • An oral antibiotic
     • An intranasal corticosteroid spray
     • A topical ocular antibiotic

     Correct answer: An intranasal corticosteroid spray

     An intranasal corticosteroid spray is the answer because intranasal corticosteroids are the most effective monotherapy for moderate-to-severe allergic rhinitis, reducing congestion, sneezing, rhinorrhea, and associated eye symptoms. Daily oral decongestants risk rebound congestion and systemic effects, and antibiotics have no role because allergic rhinitis is not an infection.

395. A 14-year-old presents with sore throat and fever but also has a hoarse voice, conjunctivitis, and a prominent cough with rhinorrhea, and the throat shows mild erythema without exudate. How should the clinician interpret these findings regarding streptococcal pharyngitis?
     • These features confirm strep, so antibiotics should start immediately
     • Hoarseness and cough are Centor criteria that raise the strep score
     • Conjunctivitis is a Centor criterion favoring strep
     • The viral features make group A streptococcal pharyngitis less likely, so routine strep testing may not be warranted

     Correct answer: The viral features make group A streptococcal pharyngitis less likely, so routine strep testing may not be warranted

     The viral features making strep less likely is the answer because hoarseness, conjunctivitis, cough, and rhinorrhea strongly suggest a viral upper respiratory infection, lowering the pretest probability of group A streptococcal pharyngitis and arguing against routine testing or empiric antibiotics. None of these features are Centor criteria, and cough specifically counts against rather than for strep.

396. A 46-year-old woman has had eight weeks of pain and swelling in the wrists and the joints at the base of her fingers, with stiffness each morning that lasts more than an hour before loosening up. She reports fatigue but no rash or fever. Which set of findings best fits an inflammatory arthritis such as rheumatoid arthritis?
     • Symmetric small-joint swelling with prolonged morning stiffness and systemic fatigue
     • Joint pain worse with use and relieved by rest, with brief stiffness
     • Sudden monoarticular pain in the great toe overnight
     • Localized lateral elbow pain reproduced by resisted wrist extension

     Correct answer: Symmetric small-joint swelling with prolonged morning stiffness and systemic fatigue

     Symmetric small-joint swelling with prolonged morning stiffness and systemic fatigue is correct because rheumatoid arthritis is an inflammatory polyarthritis that produces symmetric synovitis of the wrists and small hand joints, morning stiffness lasting longer than an hour, and constitutional symptoms such as fatigue. Pain worse with use and relieved by rest with brief stiffness describes osteoarthritis, sudden overnight great-toe pain describes gout, and lateral elbow pain on resisted wrist extension describes lateral epicondylitis.

397. A 53-year-old woman with seropositive rheumatoid arthritis is starting hydroxychloroquine as part of her treatment plan. Which baseline and follow-up screening is specifically required because of this drug's recognized toxicity?
     • Annual nerve conduction studies of both wrists
     • Baseline and periodic ophthalmologic retinal examination
     • Quarterly bone mineral density testing
     • Routine echocardiography every six months

     Correct answer: Baseline and periodic ophthalmologic retinal examination

     Baseline and periodic ophthalmologic retinal examination is correct because hydroxychloroquine can cause dose- and duration-dependent retinal toxicity (bull's-eye maculopathy), so a baseline eye exam and ongoing screening are recommended to detect early retinopathy. Nerve conduction studies, bone density testing, and routine echocardiography do not address the specific ocular risk that governs safe hydroxychloroquine use in rheumatoid arthritis.

398. A 58-year-old man with rheumatoid arthritis has progressive hand deformity. On examination one finger shows hyperextension at the proximal interphalangeal joint with flexion at the distal interphalangeal joint. Which deformity is being described?
     • Boutonniere deformity
     • Mallet finger
     • Swan-neck deformity
     • Dupuytren contracture

     Correct answer: Swan-neck deformity

     Swan-neck deformity is correct because it is defined by hyperextension at the proximal interphalangeal joint with flexion at the distal interphalangeal joint, a classic chronic hand deformity of rheumatoid arthritis. Boutonniere deformity is the reverse pattern (PIP flexion with DIP hyperextension), mallet finger is an extensor avulsion at the DIP joint, and Dupuytren contracture is a palmar fascia disorder, none of which match the described finger posture.

399. A 44-year-old woman with active rheumatoid arthritis remains symptomatic despite three months of adequately dosed methotrexate. Her clinician considers escalating therapy. Which class of agents is an appropriate add-on when methotrexate alone fails to control disease?
     • A long-acting inhaled bronchodilator
     • A proton pump inhibitor
     • A thiazide diuretic
     • A tumor necrosis factor inhibitor biologic

     Correct answer: A tumor necrosis factor inhibitor biologic

     A tumor necrosis factor inhibitor biologic is correct because when methotrexate fails to achieve adequate control in rheumatoid arthritis, adding a biologic such as a TNF inhibitor is a guideline-supported escalation step. Inhaled bronchodilators, proton pump inhibitors, and thiazide diuretics treat unrelated conditions and have no disease-modifying effect on rheumatoid synovitis.

400. A 49-year-old woman is being evaluated for possible rheumatoid arthritis. Before starting a tumor necrosis factor inhibitor, which screening test is essential because the drug can reactivate a latent infection?
     • Latent tuberculosis screening (interferon-gamma release assay or tuberculin test)
     • Screening colonoscopy
     • Fasting lipid panel
     • Carotid duplex ultrasound

     Correct answer: Latent tuberculosis screening (interferon-gamma release assay or tuberculin test)

     Latent tuberculosis screening is correct because tumor necrosis factor inhibitors used in rheumatoid arthritis can reactivate latent tuberculosis, so testing with an interferon-gamma release assay or tuberculin skin test is required before initiating therapy. A lipid panel, carotid ultrasound, and screening colonoscopy address other health concerns and do not mitigate the infection-reactivation risk of TNF inhibitors.

401. A 67-year-old man reports several years of knee pain that is worst when he first stands after sitting and after a long walk, easing with rest. Examination shows crepitus and a small varus deformity without warmth. His brief stiffness lasts only a few minutes. Which diagnosis best explains this presentation?
     • Osteoarthritis
     • Reactive arthritis
     • Septic arthritis
     • Rheumatoid arthritis

     Correct answer: Osteoarthritis

     Osteoarthritis is correct because activity-related knee pain, crepitus, malalignment, minimal warmth, and gelling stiffness lasting only minutes are characteristic of degenerative joint disease. Rheumatoid arthritis produces prolonged morning stiffness and symmetric small-joint synovitis, septic arthritis presents acutely with a hot effusion and fever, and reactive arthritis follows a recent infection with extra-articular features, none of which fit this chronic mechanical picture.

402. A 71-year-old woman with hand osteoarthritis has firm bony enlargements at the proximal interphalangeal joints. By what name are these specific nodes known?
     • Heberden nodes
     • Osler nodes
     • Janeway lesions
     • Bouchard nodes

     Correct answer: Bouchard nodes

     Bouchard nodes are correct because they are the bony osteophytic enlargements at the proximal interphalangeal joints seen in hand osteoarthritis. Heberden nodes occur at the distal interphalangeal joints, while Osler nodes and Janeway lesions are vascular findings of infective endocarditis, not features of osteoarthritis.

403. A 64-year-old man with knee osteoarthritis aspirated for an effusion has synovial fluid analyzed. Which synovial fluid white blood cell count range is most consistent with a noninflammatory osteoarthritic effusion?
     • Greater than 50,000 cells per microliter
     • Fewer than about 2,000 cells per microliter
     • About 100,000 cells per microliter with positive Gram stain
     • Between 20,000 and 30,000 cells per microliter with crystals

     Correct answer: Fewer than about 2,000 cells per microliter

     Fewer than about 2,000 cells per microliter is correct because osteoarthritis produces a noninflammatory effusion with relatively low synovial white cell counts. Counts greater than 50,000 with a positive Gram stain suggest septic arthritis, and counts in the inflammatory range with crystals suggest a crystal-induced arthropathy, neither of which reflects the bland fluid of osteoarthritis.

404. A 62-year-old runner with knee osteoarthritis asks whether continuing exercise will harm her joints. Which counseling statement is most accurate and evidence-based?
     • Low-impact strengthening and aerobic exercise improve pain and function and are recommended
     • Only high-impact running rebuilds lost cartilage
     • All exercise should be stopped to prevent further cartilage loss
     • Bracing should replace any exercise program permanently

     Correct answer: Low-impact strengthening and aerobic exercise improve pain and function and are recommended

     Low-impact strengthening and aerobic exercise improve pain and function and are recommended is correct because exercise, particularly quadriceps strengthening and low-impact aerobic activity, is a core evidence-based treatment for osteoarthritis. Stopping all activity causes deconditioning, high-impact running does not regenerate cartilage, and bracing is an adjunct rather than a substitute for an exercise program.

405. A 59-year-old man with hip osteoarthritis has refractory pain and severe functional limitation despite maximal medical therapy and physical therapy. Which intervention is the definitive treatment for end-stage hip osteoarthritis?
     • Indefinite opioid therapy
     • Long-term oral antibiotics
     • Serial therapeutic phlebotomy
     • Total hip arthroplasty

     Correct answer: Total hip arthroplasty

     Total hip arthroplasty is correct because joint replacement is the definitive treatment for end-stage hip osteoarthritis with disabling pain unresponsive to conservative care. Indefinite opioids carry dependence and adverse-effect risks without addressing the structural disease, and antibiotics and phlebotomy have no role in degenerative joint disease.

406. A 56-year-old man with obesity, hypertension, and heavy alcohol use awakens with excruciating pain, redness, and swelling of his first metatarsophalangeal joint. He had a similar episode last year. Which underlying metabolic abnormality most directly drives this presentation?
     • Hyperuricemia leading to monosodium urate crystal deposition
     • Calcium pyrophosphate deposition from hyperparathyroidism
     • Autoimmune citrullinated peptide antibodies
     • Iron overload from hemochromatosis

     Correct answer: Hyperuricemia leading to monosodium urate crystal deposition

     Hyperuricemia leading to monosodium urate crystal deposition is correct because acute podagra of the first metatarsophalangeal joint results from monosodium urate crystals precipitating in the setting of elevated serum urate. Calcium pyrophosphate deposition causes pseudogout, anti-CCP antibodies drive rheumatoid arthritis, and iron overload causes hemochromatosis arthropathy, none of which produces classic acute gouty podagra.

407. A 60-year-old man has an acute gout flare but also has chronic kidney disease and a peptic ulcer history that make NSAIDs unsuitable, and colchicine is poorly tolerated. Which treatment is an appropriate alternative for the acute flare?
     • Initiation of allopurinol at high dose
     • A short course of oral corticosteroids
     • Starting probenecid
     • Beginning pegloticase

     Correct answer: A short course of oral corticosteroids

     A short course of oral corticosteroids is correct because when NSAIDs and colchicine are contraindicated or not tolerated, glucocorticoids effectively treat the inflammation of an acute gout flare. Allopurinol and probenecid are urate-lowering therapies that should not be started during an attack, and pegloticase is reserved for refractory chronic gout, so none of those treats this acute flare appropriately.

408. A 57-year-old man is started on allopurinol for recurrent gout. During the first weeks of urate-lowering therapy he experiences a flare. Which co-prescribed measure helps prevent flares when initiating urate-lowering treatment?
     • Low-dose colchicine or NSAID prophylaxis during initiation
     • A high-purine diet to stabilize urate
     • Stopping all fluids to reduce urate load
     • Immediate cessation of allopurinol at first twinge

     Correct answer: Low-dose colchicine or NSAID prophylaxis during initiation

     Low-dose colchicine or NSAID prophylaxis during initiation is correct because shifting urate levels at the start of urate-lowering therapy can precipitate flares, so anti-inflammatory prophylaxis is recommended during initiation. Reducing fluids and eating a high-purine diet raise urate and worsen gout, and stopping allopurinol at the first symptom destabilizes urate and prolongs flares.

409. A 78-year-old woman with osteoarthritis presents with acute knee pain and swelling. Synovial fluid shows positively birefringent rhomboid crystals, and radiographs reveal linear calcification within the meniscal cartilage. Which underlying condition is most associated with this crystal arthropathy?
     • Hyperthyroidism
     • Hemophilia
     • Cystic fibrosis
     • Hyperparathyroidism

     Correct answer: Hyperparathyroidism

     Hyperparathyroidism is correct because calcium pyrophosphate deposition disease (pseudogout) is associated with metabolic conditions including hyperparathyroidism, hemochromatosis, and hypomagnesemia, which should be evaluated when chondrocalcinosis is found. Hyperthyroidism, hemophilia, and cystic fibrosis are not the recognized metabolic associations that prompt workup in pseudogout.

410. A clinician must distinguish an acute gout flare from septic arthritis in a patient with a hot, swollen knee. Which step is most essential before attributing the joint inflammation to crystals alone?
     • Arthrocentesis with synovial fluid Gram stain, culture, cell count, and crystal analysis
     • Serum uric acid level alone to confirm or exclude infection
     • Empiric long-term allopurinol without aspiration
     • Plain radiograph alone to rule out infection

     Correct answer: Arthrocentesis with synovial fluid Gram stain, culture, cell count, and crystal analysis

     Arthrocentesis with synovial fluid Gram stain, culture, cell count, and crystal analysis is correct because a hot swollen joint can represent septic arthritis even when crystals are present, so joint aspiration with full fluid analysis is essential to exclude infection. A serum uric acid level can be normal during a flare and cannot exclude infection, radiographs do not diagnose infection, and starting allopurinol without aspiration risks missing a joint infection.

411. A 68-year-old postmenopausal woman sustains a wrist fracture after tripping at standing height. She has no secondary causes identified. Which T-score threshold on dual-energy X-ray absorptiometry defines osteoporosis by densitometric criteria?
     • T-score of -1.0 or lower
     • T-score of -2.5 or lower
     • T-score of +1.0 or higher
     • T-score between -0.5 and -1.0

     Correct answer: T-score of -2.5 or lower

     T-score of -2.5 or lower is correct because the World Health Organization defines osteoporosis as a bone mineral density T-score at or below -2.5 standard deviations. A T-score between -1.0 and -2.5 indicates osteopenia, a T-score at or above -1.0 is normal, and values near 0 or positive reflect normal or above-average density rather than osteoporosis.

412. A clinician wants to estimate a patient's 10-year probability of major osteoporotic and hip fracture to guide treatment decisions, particularly in patients with osteopenia. Which tool is designed for this purpose?
     • CHA2DS2-VASc score
     • FRAX (Fracture Risk Assessment Tool)
     • Wells criteria
     • MELD score

     Correct answer: FRAX (Fracture Risk Assessment Tool)

     FRAX is correct because it integrates clinical risk factors with bone density to estimate a patient's 10-year probability of major osteoporotic and hip fracture, helping decide whether to treat patients with osteopenia. The CHA2DS2-VASc score estimates stroke risk in atrial fibrillation, the Wells criteria assess venous thromboembolism probability, and the MELD score grades liver disease severity, none of which estimate fracture risk.

413. A 70-year-old woman with osteoporosis is intolerant of oral bisphosphonates and has had a prior vertebral fracture with very high fracture risk. Which agent is an anabolic (bone-building) option distinct from antiresorptive therapy?
     • Alendronate
     • Calcitonin nasal spray
     • Teriparatide
     • Hydrochlorothiazide

     Correct answer: Teriparatide

     Teriparatide is correct because it is a recombinant parathyroid hormone analog that stimulates new bone formation, making it an anabolic option for patients with very high fracture risk or intolerance to antiresorptives. Alendronate is an antiresorptive bisphosphonate, calcitonin is a weak antiresorptive, and hydrochlorothiazide is a diuretic, so none of those is an anabolic osteoporosis agent.

414. A 65-year-old woman beginning osteoporosis therapy asks about supplements that support bone health alongside her prescription medication. Which two supplements are routinely recommended as adjuncts to pharmacologic osteoporosis treatment?
     • Iron and folate
     • Vitamin B12 and thiamine
     • Calcium and vitamin D
     • Potassium and magnesium only

     Correct answer: Calcium and vitamin D

     Calcium and vitamin D are correct because adequate calcium and vitamin D intake supports bone mineralization and is recommended alongside pharmacologic therapy for osteoporosis. Iron and folate address anemia, vitamin B12 and thiamine address neurologic and nutritional deficits, and potassium and magnesium are electrolytes, none of which serve as the standard bone-health adjuncts in osteoporosis care.

415. A 55-year-old man taking high-dose chronic oral glucocorticoids for an inflammatory condition is at increased risk for a skeletal complication. Which preventive bone evaluation and management is indicated for glucocorticoid-induced bone loss?
     • Routine serial chest radiographs
     • Annual nerve conduction studies
     • Quarterly synovial fluid analysis
     • Bone mineral density assessment and consideration of bisphosphonate therapy

     Correct answer: Bone mineral density assessment and consideration of bisphosphonate therapy

     Bone mineral density assessment and consideration of bisphosphonate therapy is correct because chronic glucocorticoids accelerate bone loss and fracture risk, so bone density testing and prophylactic antiresorptive therapy with calcium and vitamin D are recommended. Chest radiographs, nerve conduction studies, and synovial fluid analysis do not address glucocorticoid-induced osteoporosis.

416. A 40-year-old keyboard operator describes numbness and tingling of the thumb, index, and middle fingers that wakes her at night, with relief after shaking the hand. Examination shows reduced sensation over the palmar thumb and index finger. Which condition does this distribution most strongly suggest?
     • Carpal tunnel syndrome
     • Cubital tunnel syndrome
     • C8 radiculopathy
     • Thoracic outlet syndrome

     Correct answer: Carpal tunnel syndrome

     Carpal tunnel syndrome is correct because median nerve compression at the wrist produces nocturnal paresthesias and sensory loss in the thumb, index, middle, and radial ring finger, relieved by shaking the hand. Cubital tunnel syndrome and C8 radiculopathy affect the small finger and medial hand, and thoracic outlet syndrome typically causes more diffuse arm symptoms, none matching the median distribution.

417. A 45-year-old woman has clinically suspected carpal tunnel syndrome. Which test is considered the most useful objective study to confirm the diagnosis and assess severity when the diagnosis is uncertain or surgery is planned?
     • Plain wrist radiographs
     • Nerve conduction studies and electromyography
     • Dual-energy X-ray absorptiometry
     • Serum rheumatoid factor

     Correct answer: Nerve conduction studies and electromyography

     Nerve conduction studies and electromyography are correct because electrodiagnostic testing objectively confirms median nerve dysfunction at the wrist and grades severity, which is useful when the diagnosis is unclear or surgery is contemplated. Wrist radiographs assess bone, DEXA measures bone density, and rheumatoid factor screens for autoimmune disease, none of which evaluates median nerve conduction.

418. A 50-year-old woman has carpal tunnel symptoms refractory to nighttime splinting and activity modification, but she has no thenar atrophy and declines surgery. Which nonsurgical intervention is a reasonable next step to reduce inflammation around the median nerve?
     • Systemic broad-spectrum antibiotics
     • Long-arm casting for three months
     • Local corticosteroid injection into the carpal tunnel
     • Therapeutic phlebotomy

     Correct answer: Local corticosteroid injection into the carpal tunnel

     Local corticosteroid injection into the carpal tunnel is correct because a local steroid injection can reduce inflammation and provide symptomatic relief when splinting fails and surgery is declined in carpal tunnel syndrome. Systemic antibiotics treat infection, long-arm casting causes stiffness without targeting the median nerve, and phlebotomy has no role in nerve entrapment.

419. A clinician examines a patient for carpal tunnel syndrome by tapping over the volar wrist to reproduce tingling in the median nerve distribution. Which named sign is this maneuver testing?
     • Murphy sign
     • Homan sign
     • Trousseau sign
     • Tinel sign

     Correct answer: Tinel sign

     Tinel sign is correct because percussion over the median nerve at the volar wrist that reproduces paresthesias in the median distribution is a positive Tinel sign supporting carpal tunnel syndrome. Murphy sign relates to cholecystitis, Homan sign to deep vein thrombosis, and Trousseau sign to hypocalcemia, none of which evaluates median nerve irritability at the wrist.

420. A 37-year-old healthy man developed acute low back pain three days ago after moving furniture. He has no leg weakness, no bladder or bowel changes, no fever, and a normal neurologic examination. Which red flag, if present, would change his low-risk classification and prompt urgent imaging?
     • New saddle anesthesia with urinary retention
     • Pain that improves with rest and activity modification
     • Localized paraspinal muscle tenderness
     • Mild stiffness in the morning that loosens up

     Correct answer: New saddle anesthesia with urinary retention

     New saddle anesthesia with urinary retention is correct because these are hallmark red flags for cauda equina syndrome, demanding urgent imaging and surgical evaluation. Pain improving with rest, paraspinal tenderness, and mild morning stiffness that loosens are reassuring features of nonspecific mechanical back pain rather than red flags.

421. A 33-year-old man reports sharp low back pain radiating down the posterior leg below the knee, with numbness along the lateral foot. Straight-leg raise reproduces the radicular pain. Which finding indicates lumbar nerve root involvement (radiculopathy) rather than simple mechanical back pain?
     • Diffuse aching across both flanks without leg symptoms
     • Dermatomal sensory loss with a positive straight-leg raise
     • Pain limited to the lumbar muscles with full strength
     • Stiffness relieved entirely by a single dose of acetaminophen

     Correct answer: Dermatomal sensory loss with a positive straight-leg raise

     Dermatomal sensory loss with a positive straight-leg raise is correct because radicular pain following a dermatome with a positive straight-leg raise indicates nerve root compression, typically from a herniated lumbar disc. Diffuse flank aching, isolated muscle pain with full strength, and stiffness fully relieved by acetaminophen reflect nonspecific mechanical back pain without radiculopathy.

422. A 24-year-old man has had insidious low back pain and stiffness for more than three months that is worst in the early morning, improves with exercise, and is associated with reduced spinal mobility. Which condition should be considered given this inflammatory back pain pattern?
     • Acute lumbar muscle strain
     • Vertebral compression fracture
     • Ankylosing spondylitis (axial spondyloarthritis)
     • Simple postural back pain

     Correct answer: Ankylosing spondylitis (axial spondyloarthritis)

     Ankylosing spondylitis is correct because chronic back pain in a young adult that is worse in the morning, improves with activity, lasts more than three months, and reduces spinal mobility describes inflammatory back pain typical of axial spondyloarthritis. Mechanical strain and postural pain worsen with activity and lack prolonged morning stiffness, and a compression fracture causes acute pain, usually in older or osteoporotic patients.

423. A 68-year-old woman with osteoporosis develops sudden mid-back pain after a minor fall, with focal tenderness over a thoracic vertebra and no neurologic deficit. Which diagnosis should be suspected as the cause of this acute back pain?
     • Lumbar disc herniation
     • Piriformis syndrome
     • Sacroiliac joint dysfunction
     • Vertebral compression fracture

     Correct answer: Vertebral compression fracture

     Vertebral compression fracture is correct because acute focal spinal pain after minor trauma in an older patient with osteoporosis points to a fragility compression fracture. Lumbar disc herniation typically causes radicular leg symptoms, while piriformis syndrome and sacroiliac dysfunction cause buttock and posterior pain rather than acute focal vertebral tenderness after a fall.

424. A 54-year-old warehouse worker reports gradual right shoulder pain and difficulty lifting objects overhead, with weakness on abduction. Plain films are normal. The examiner places the arm in passive abduction and asks the patient to lower it slowly; the arm drops abruptly. Which test is positive and what does it suggest?
     • Positive drop-arm test suggesting a rotator cuff tear
     • Positive Finkelstein test suggesting de Quervain tenosynovitis
     • Positive Spurling test suggesting cervical radiculopathy
     • Positive Thomas test suggesting hip flexor contracture

     Correct answer: Positive drop-arm test suggesting a rotator cuff tear

     Positive drop-arm test suggesting a rotator cuff tear is correct because inability to slowly lower the abducted arm, with the arm dropping abruptly, indicates significant rotator cuff (especially supraspinatus) dysfunction. The Spurling test evaluates cervical radiculopathy, the Finkelstein test evaluates de Quervain tenosynovitis at the wrist, and the Thomas test evaluates hip flexor tightness, none of which assesses the rotator cuff.

425. A 60-year-old man has chronic shoulder pain worse with overhead reaching. The examiner passively forward-flexes the shoulder to 90 degrees and then internally rotates it, reproducing pain. Which test is being performed and what does it evaluate?
     • Lachman test evaluating the anterior cruciate ligament
     • Hawkins-Kennedy test evaluating subacromial impingement
     • McMurray test evaluating a meniscal tear
     • Ober test evaluating iliotibial band tightness

     Correct answer: Hawkins-Kennedy test evaluating subacromial impingement

     Hawkins-Kennedy test evaluating subacromial impingement is correct because forward flexion to 90 degrees followed by internal rotation that reproduces pain indicates subacromial impingement, often related to rotator cuff pathology. The Lachman and McMurray tests assess knee structures and the Ober test assesses the iliotibial band, none of which evaluates the shoulder.

426. A 70-year-old man has an acute, full-thickness rotator cuff tear after a fall, with marked weakness of abduction and external rotation, and he is otherwise healthy and active. Which management approach is most appropriate for an acute full-thickness tear with significant functional loss?
     • Referral for surgical rotator cuff repair
     • Long-term oral antibiotics
     • Indefinite sling immobilization without therapy
     • Reassurance with no follow-up needed

     Correct answer: Referral for surgical rotator cuff repair

     Referral for surgical rotator cuff repair is correct because acute full-thickness tears with substantial weakness in active, healthy patients are often managed surgically to restore function. Indefinite immobilization promotes stiffness, antibiotics are irrelevant to a noninfectious tendon tear, and reassurance without follow-up neglects a functionally significant injury.

427. A 50-year-old painter has chronic shoulder pain attributed to subacromial impingement and rotator cuff tendinopathy without a full-thickness tear. Which combination represents appropriate first-line conservative management?
     • Immediate joint replacement
     • Complete arm immobilization for three months
     • Systemic corticosteroids indefinitely
     • Relative rest, NSAIDs, and a structured physical therapy program

     Correct answer: Relative rest, NSAIDs, and a structured physical therapy program

     Relative rest, NSAIDs, and a structured physical therapy program is correct because rotator cuff tendinopathy and impingement without a full-thickness tear respond to activity modification, anti-inflammatory medication, and rehabilitation focused on cuff and scapular strengthening. Joint replacement is not indicated for tendinopathy, prolonged immobilization causes adhesive capsulitis, and indefinite systemic steroids carry unacceptable risk.

428. A 19-year-old soccer player twists the knee while pivoting, hears a pop, and develops immediate swelling and instability. The examiner stabilizes the femur and pulls the flexed-30-degree tibia forward, finding increased anterior translation with a soft endpoint. Which structure is most likely injured?
     • Posterior cruciate ligament
     • Anterior cruciate ligament
     • Medial collateral ligament
     • Lateral meniscus only

     Correct answer: Anterior cruciate ligament

     Anterior cruciate ligament is correct because a pivoting injury with an audible pop, rapid hemarthrosis, instability, and increased anterior tibial translation with a soft endpoint on the Lachman test indicates an ACL tear. The posterior cruciate ligament is tested by posterior translation, the medial collateral ligament by valgus stress, and a meniscal tear by joint-line tenderness and McMurray testing rather than anterior laxity.

429. A 27-year-old recreational athlete has medial knee pain and intermittent locking after a twisting injury. The examiner flexes the knee, externally rotates the tibia, and extends the knee, producing a painful click along the medial joint line. Which test is positive and what does it assess?
     • Positive anterior drawer assessing the ACL
     • Positive McMurray test assessing a meniscal tear
     • Positive Phalen test assessing the median nerve
     • Positive Trendelenburg test assessing hip abductors

     Correct answer: Positive McMurray test assessing a meniscal tear

     Positive McMurray test assessing a meniscal tear is correct because a painful click along the joint line during rotation and extension of the flexed knee indicates a meniscal tear. The anterior drawer assesses the ACL, the Phalen test assesses the median nerve at the wrist, and the Trendelenburg test assesses hip abductor strength, none of which evaluates the meniscus.

430. A 35-year-old man is struck on the lateral knee while the foot is planted, causing medial knee pain and laxity. The examiner applies valgus stress at 30 degrees of flexion and finds increased medial opening. Which ligament is most likely injured?
     • Anterior cruciate ligament
     • Posterior cruciate ligament
     • Medial collateral ligament
     • Patellar tendon

     Correct answer: Medial collateral ligament

     Medial collateral ligament is correct because a lateral blow producing medial laxity with increased medial joint opening on valgus stress testing indicates an MCL injury. The cruciate ligaments are tested by anterior or posterior translation rather than valgus stress, and the patellar tendon is an extensor structure, not a collateral stabilizer.

431. A 16-year-old basketball player rolls the ankle inward (inversion) and has lateral ankle pain and swelling. Using the Ottawa ankle rules, which finding would most clearly indicate the need for ankle radiographs?
     • Mild lateral swelling that resolves within an hour
     • Full pain-free range of motion with normal gait
     • Inability to bear weight for four steps both immediately and in the office
     • Tenderness limited to the soft tissue distal to the malleoli

     Correct answer: Inability to bear weight for four steps both immediately and in the office

     Inability to bear weight for four steps both immediately and in the office is correct because the Ottawa ankle rules recommend radiographs when the patient cannot bear weight for four steps or has bony tenderness at the posterior malleoli or specific midfoot landmarks. Mild transient soft-tissue swelling, pain-free range of motion with normal gait, and isolated soft-tissue tenderness do not meet criteria for imaging.

432. A 22-year-old runner has lateral ankle pain after an inversion injury with negative radiographs, consistent with a lateral ligament sprain. Which initial management best reflects current recommendations for an acute uncomplicated ankle sprain?
     • Strict non-weight-bearing in a long-leg cast for six weeks
     • Immediate surgical ligament reconstruction
     • Relative rest, ice, compression, elevation, and early functional mobilization
     • Complete bed rest until all pain resolves

     Correct answer: Relative rest, ice, compression, elevation, and early functional mobilization

     Relative rest, ice, compression, elevation, and early functional mobilization is correct because acute uncomplicated ankle sprains are treated with protection, ice, compression, elevation, and early controlled movement and rehabilitation to restore function. Prolonged casting and bed rest promote stiffness and weakness, and surgery is reserved for select severe or refractory injuries rather than routine sprains.

433. A 38-year-old recreational tennis player suddenly feels a sharp pain in the back of the ankle as if kicked, then has difficulty pushing off and walking. Examination shows a palpable gap in the tendon and absent plantarflexion when the calf is squeezed. Which injury is most likely?
     • Plantar fasciitis
     • Medial malleolus fracture
     • Tibialis anterior strain
     • Achilles tendon rupture

     Correct answer: Achilles tendon rupture

     Achilles tendon rupture is correct because a sudden posterior ankle pain with a palpable tendon gap and a positive Thompson test (absent plantarflexion when squeezing the calf) is diagnostic of Achilles rupture. Plantar fasciitis causes heel pain on weight bearing, a medial malleolus fracture causes bony tenderness, and an anterior tibialis strain affects dorsiflexion, none of which produces a positive Thompson test.

434. A 45-year-old man with shoulder stiffness has had progressive loss of both active and passive range of motion over several months, with painful global restriction and no history of trauma; he has diabetes. Which condition best explains loss of passive as well as active motion?
     • Isolated rotator cuff tear
     • Adhesive capsulitis (frozen shoulder)
     • Acromioclavicular joint sprain
     • Biceps tendon subluxation

     Correct answer: Adhesive capsulitis (frozen shoulder)

     Adhesive capsulitis (frozen shoulder) is correct because loss of both active and passive range of motion with global stiffness, often in patients with diabetes, characterizes capsular contracture. An isolated rotator cuff tear limits active motion more than passive, and acromioclavicular sprain and biceps subluxation cause focal pain without global loss of passive motion.

435. A 30-year-old runner reports gradual onset of heel pain that is worst with the first steps in the morning and after periods of rest, improving with activity, with tenderness at the medial calcaneal tubercle. Which diagnosis is most consistent with these findings?
     • Tarsal tunnel syndrome
     • Achilles tendon rupture
     • Plantar fasciitis
     • Stress fracture of the femoral neck

     Correct answer: Plantar fasciitis

     Plantar fasciitis is correct because heel pain that is worst with the first steps in the morning, improves with activity, and reproduces with tenderness at the medial calcaneal tubercle is classic for plantar fasciitis. Tarsal tunnel syndrome causes burning paresthesias from posterior tibial nerve compression, Achilles rupture causes acute posterior ankle pain, and a femoral neck stress fracture causes hip or groin pain, not plantar heel pain.

436. A 47-year-old laborer reports lateral elbow pain that worsens when gripping objects and lifting with the palm down. Examination reproduces pain over the lateral epicondyle with resisted wrist extension. Which condition is most consistent with this presentation?
     • Medial epicondylitis (golfer's elbow)
     • Olecranon bursitis
     • Cubital tunnel syndrome
     • Lateral epicondylitis (tennis elbow)

     Correct answer: Lateral epicondylitis (tennis elbow)

     Lateral epicondylitis (tennis elbow) is correct because pain over the lateral epicondyle reproduced by resisted wrist extension and gripping reflects overuse of the common extensor origin. Medial epicondylitis causes medial elbow pain with resisted wrist flexion, olecranon bursitis presents as posterior swelling over the olecranon, and cubital tunnel syndrome causes ulnar nerve paresthesias rather than lateral epicondyle pain.

437. A 26-year-old new mother reports radial-sided wrist pain near the base of the thumb when lifting her infant. The examiner has her flex the thumb into the palm and ulnar-deviate the wrist, which sharply reproduces the pain. Which condition does this positive maneuver indicate?
     • Carpal tunnel syndrome
     • Scaphoid fracture
     • First carpometacarpal osteoarthritis
     • De Quervain tenosynovitis

     Correct answer: De Quervain tenosynovitis

     De Quervain tenosynovitis is correct because radial-sided wrist pain reproduced by the Finkelstein maneuver (thumb flexed into the palm with ulnar deviation) indicates inflammation of the abductor pollicis longus and extensor pollicis brevis tendons. Carpal tunnel syndrome causes median nerve paresthesias, a scaphoid fracture causes snuffbox tenderness after a fall, and first carpometacarpal osteoarthritis causes pain at the thumb base joint rather than a positive Finkelstein test.

438. A 33-year-old man has elbow pain on the inner aspect that worsens with forceful gripping and throwing, reproduced by resisted wrist flexion and forearm pronation. Which condition does this presentation most likely represent?
     • Lateral epicondylitis (tennis elbow)
     • Medial epicondylitis (golfer's elbow)
     • Distal biceps tendon rupture
     • Radial head fracture

     Correct answer: Medial epicondylitis (golfer's elbow)

     Medial epicondylitis (golfer's elbow) is correct because medial elbow pain reproduced by resisted wrist flexion and forearm pronation reflects overuse of the common flexor-pronator origin at the medial epicondyle. Lateral epicondylitis causes lateral pain with resisted wrist extension, a distal biceps rupture causes a sudden pop with weak supination and flexion, and a radial head fracture causes lateral pain after trauma, none matching the medial flexor pattern.

439. A 40-year-old woman develops carpal tunnel symptoms during pregnancy with nocturnal numbness in the median distribution and no thenar weakness. Which statement about her course and management is most accurate?
     • Immediate surgical release is required during pregnancy
     • Symptoms indicate permanent median nerve infarction
     • Pregnancy-related fluid retention can precipitate symptoms that often improve postpartum, so splinting is preferred
     • Wrist splinting is contraindicated in pregnancy

     Correct answer: Pregnancy-related fluid retention can precipitate symptoms that often improve postpartum, so splinting is preferred

     Pregnancy-related fluid retention can precipitate symptoms that often improve postpartum, so splinting is preferred is correct because increased fluid volume raises carpal tunnel pressure, symptoms commonly resolve after delivery, and conservative nocturnal splinting is the appropriate first-line approach. Surgery is not warranted without motor deficits, symptoms do not reflect permanent infarction, and splinting is safe and recommended in pregnancy.

440. A 34-year-old woman reports six weeks of persistently low mood, loss of interest in activities she used to enjoy, poor concentration, early-morning awakening, and feelings of worthlessness. She denies manic symptoms or substance use. Which diagnosis best fits this presentation?
     • Major depressive disorder
     • Adjustment disorder with depressed mood
     • Persistent depressive disorder
     • Cyclothymic disorder

     Correct answer: Major depressive disorder

     Major depressive disorder is correct because the patient meets the threshold of at least five depressive symptoms, including depressed mood and anhedonia, present nearly every day for at least two weeks. Adjustment disorder requires an identifiable stressor and milder symptoms, persistent depressive disorder requires depressed mood lasting at least two years, and cyclothymic disorder involves alternating hypomanic and depressive symptoms.

441. A clinician plans to start pharmacotherapy for a patient newly diagnosed with major depressive disorder and no contraindications. Which medication class is recommended as first-line treatment?
     • Monoamine oxidase inhibitors
     • Selective serotonin reuptake inhibitors
     • Tricyclic antidepressants
     • Typical antipsychotics

     Correct answer: Selective serotonin reuptake inhibitors

     Selective serotonin reuptake inhibitors are correct because they are first-line for major depressive disorder owing to their favorable safety profile and tolerability. Tricyclic antidepressants and monoamine oxidase inhibitors are reserved for refractory cases because of cardiotoxicity, anticholinergic effects, and dietary or drug interactions, and typical antipsychotics do not treat uncomplicated depression.

442. A 45-year-old man started on a selective serotonin reuptake inhibitor for depression reports that after several weeks his mood has improved but he now has difficulty achieving orgasm. Which approach is most appropriate when sexual dysfunction limits adherence?
     • Add a benzodiazepine to counteract the side effect
     • Abruptly stop all antidepressant therapy
     • Switch to bupropion, which has a lower rate of sexual side effects
     • Double the current SSRI dose to overcome the effect

     Correct answer: Switch to bupropion, which has a lower rate of sexual side effects

     Switching to bupropion is correct because bupropion acts on dopamine and norepinephrine and carries a markedly lower rate of sexual dysfunction than SSRIs, making it a preferred alternative when this side effect threatens adherence. Adding a benzodiazepine does not address the problem, abrupt cessation risks discontinuation syndrome and relapse, and increasing the SSRI dose typically worsens sexual side effects.

443. Which standardized instrument is most commonly used in primary care to screen for and monitor the severity of depression?
     • GAD-7
     • MMSE
     • AUDIT-C
     • PHQ-9

     Correct answer: PHQ-9

     The PHQ-9 is correct because this nine-item questionnaire maps directly onto the diagnostic criteria for major depressive disorder and is validated for both screening and tracking severity over time. The GAD-7 screens for anxiety, the MMSE assesses cognition, and the AUDIT-C screens for alcohol use.

444. A 19-year-old college student started on fluoxetine two weeks ago for moderate depression returns for follow-up. Regarding suicide risk in this age group, which counseling point is most important?
     • Increased suicidal ideation can occur early in treatment in patients under 25, warranting close monitoring
     • Antidepressants eliminate suicide risk within the first week of therapy
     • Suicide risk only becomes relevant after one year of treatment
     • Younger patients have no elevated risk and need no special follow-up

     Correct answer: Increased suicidal ideation can occur early in treatment in patients under 25, warranting close monitoring

     Close early monitoring is correct because antidepressants carry a boxed warning for increased suicidal ideation in patients younger than 25, particularly during the first weeks of therapy before mood fully improves. Antidepressants do not eliminate risk immediately, the risk is greatest early rather than only after a year, and younger patients specifically require heightened surveillance.

445. A 28-year-old woman reports six months of excessive, hard-to-control worry about work, finances, and health, accompanied by restlessness, muscle tension, fatigue, and trouble sleeping. Which diagnosis best explains her presentation?
     • Panic disorder
     • Generalized anxiety disorder
     • Social anxiety disorder
     • Specific phobia

     Correct answer: Generalized anxiety disorder

     Generalized anxiety disorder is correct because it is defined by excessive worry occurring more days than not for at least six months across multiple domains, with associated symptoms such as restlessness, muscle tension, and sleep disturbance. Panic disorder centers on recurrent unexpected panic attacks, social anxiety disorder involves fear of scrutiny in social situations, and specific phobia is fear of a circumscribed object or situation.

446. Which medication classes are considered first-line pharmacotherapy for generalized anxiety disorder?
     • Benzodiazepines and barbiturates
     • Typical antipsychotics and lithium
     • SSRIs and SNRIs
     • Stimulants and beta-blockers

     Correct answer: SSRIs and SNRIs

     SSRIs and SNRIs are correct because they provide durable control of chronic anxiety without the dependence risk of other agents and are recommended first-line for generalized anxiety disorder. Benzodiazepines carry tolerance and dependence concerns and are not preferred for long-term use, typical antipsychotics and lithium are not indicated, and stimulants would worsen anxiety.

447. A 52-year-old patient with generalized anxiety disorder asks for a non-benzodiazepine, non-antidepressant option that is not sedating and has no dependence potential. Which agent best fits this request?
     • Alprazolam
     • Zolpidem
     • Diphenhydramine
     • Buspirone

     Correct answer: Buspirone

     Buspirone is correct because it is a serotonin 5-HT1A partial agonist used for generalized anxiety disorder that is non-sedating and carries no dependence potential, though it requires weeks for full effect. Alprazolam is a benzodiazepine with dependence risk, zolpidem is a hypnotic for insomnia, and diphenhydramine is a sedating antihistamine not indicated for chronic anxiety management.

448. Which brief, validated self-report instrument is most appropriate for screening and measuring the severity of generalized anxiety disorder in primary care?
     • GAD-7
     • PHQ-9
     • CAGE questionnaire
     • Hamilton Depression Rating Scale

     Correct answer: GAD-7

     The GAD-7 is correct because this seven-item scale is specifically validated to identify and grade the severity of generalized anxiety disorder. The PHQ-9 screens for depression, the CAGE questionnaire screens for alcohol use, and the Hamilton Depression Rating Scale is a clinician-administered depression measure.

449. A 24-year-old man describes recurrent, sudden episodes of intense fear that peak within minutes, with palpitations, chest tightness, shortness of breath, and a fear of dying, followed by persistent worry about having more episodes. Cardiac workup is unremarkable. Which disorder best accounts for these findings?
     • Generalized anxiety disorder
     • Panic disorder
     • Obsessive-compulsive disorder
     • Illness anxiety disorder

     Correct answer: Panic disorder

     Panic disorder is correct because it is characterized by recurrent unexpected panic attacks that peak within minutes plus at least a month of persistent concern about additional attacks. Generalized anxiety disorder involves chronic worry rather than discrete attacks, obsessive-compulsive disorder features obsessions and compulsions, and illness anxiety disorder centers on preoccupation with having a serious illness.

450. A 26-year-old man is brought in by family because for the past week he has slept only two hours nightly, talks rapidly about a plan to start three businesses, has spent thousands of dollars impulsively, and feels he needs no rest. He has had prior depressive episodes. Which diagnosis is most likely?
     • Major depressive disorder, recurrent
     • Cyclothymic disorder
     • Bipolar I disorder
     • Generalized anxiety disorder

     Correct answer: Bipolar I disorder

     Bipolar I disorder is correct because a distinct period of elevated mood with decreased need for sleep, pressured speech, grandiosity, and risky spending lasting at least a week meets criteria for a manic episode, which defines bipolar I. Recurrent major depression lacks manic episodes, cyclothymic disorder involves subthreshold symptoms over two years, and generalized anxiety disorder does not produce mania.

451. What is the minimum duration of elevated or irritable mood with associated symptoms required to define a manic episode in bipolar I disorder?
     • At least 24 hours
     • At least 2 weeks
     • At least 6 months
     • At least 1 week (or any duration if hospitalization is required)

     Correct answer: At least 1 week (or any duration if hospitalization is required)

     At least one week is correct because a manic episode requires the mood disturbance to last at least seven days, or any duration if hospitalization becomes necessary. A hypomanic episode requires at least four days, the two-week threshold applies to major depressive episodes, and six months is not a mood-episode criterion.

452. A 30-year-old woman with bipolar I disorder is to begin maintenance therapy. Which medication is a classic mood stabilizer that also reduces suicide risk and requires monitoring of serum drug levels and renal and thyroid function?
     • Lithium
     • Sertraline
     • Bupropion
     • Lorazepam

     Correct answer: Lithium

     Lithium is correct because it is a foundational mood stabilizer for bipolar disorder with demonstrated anti-suicide benefit and a narrow therapeutic index that mandates monitoring of serum levels along with renal and thyroid function. Sertraline and bupropion are antidepressants that can precipitate mania if used without a mood stabilizer, and lorazepam is a benzodiazepine used adjunctively but is not a maintenance mood stabilizer.

453. Why is starting an antidepressant alone generally avoided in a patient with bipolar disorder presenting in a depressive phase?
     • Antidepressants are ineffective for any depressive symptoms
     • Antidepressant monotherapy can trigger a switch into mania or hypomania
     • Antidepressants always cause lithium toxicity
     • Antidepressants are contraindicated with any psychotherapy

     Correct answer: Antidepressant monotherapy can trigger a switch into mania or hypomania

     Triggering a manic or hypomanic switch is correct because antidepressants used without a mood stabilizer can destabilize mood and precipitate mania in bipolar patients, so a mood stabilizer is the foundation of treatment. Antidepressants are not universally ineffective, do not invariably cause lithium toxicity, and are not contraindicated with psychotherapy.

454. A 22-year-old man has had six months of declining function with auditory hallucinations, a fixed belief that the government is monitoring him, disorganized speech, and social withdrawal, without prominent mood symptoms. Which diagnosis best fits?
     • Schizophreniform disorder
     • Brief psychotic disorder
     • Schizophrenia
     • Bipolar I disorder with psychotic features

     Correct answer: Schizophrenia

     Schizophrenia is correct because continuous signs of the disturbance, including at least one month of active psychotic symptoms, persist for six months or longer with marked functional decline. Schizophreniform disorder lasts one to six months, brief psychotic disorder resolves within one month, and bipolar disorder with psychotic features would include a prominent mood episode driving the psychosis.

455. Hallucinations, delusions, and disorganized speech in schizophrenia are best categorized as which type of symptom?
     • Negative symptoms
     • Cognitive symptoms
     • Extrapyramidal symptoms
     • Positive symptoms

     Correct answer: Positive symptoms

     Positive symptoms are correct because they represent an excess or distortion of normal function, such as hallucinations, delusions, and disorganized speech. Negative symptoms reflect a loss of function such as flat affect and avolition, cognitive symptoms involve impaired attention and memory, and extrapyramidal symptoms are motor side effects of antipsychotic medications.

456. A patient with treatment-resistant schizophrenia who has failed two adequate antipsychotic trials is being considered for clozapine. Which laboratory parameter must be monitored regularly because of a serious adverse effect of this drug?
     • Absolute neutrophil count
     • Serum lithium level
     • Serum lipase
     • Vitamin B12 level

     Correct answer: Absolute neutrophil count

     Absolute neutrophil count is correct because clozapine can cause severe neutropenia and agranulocytosis, requiring scheduled blood count monitoring to detect this hematologic risk early. Lithium levels are tracked for mood stabilizer therapy, lipase relates to pancreatitis, and vitamin B12 is unrelated to clozapine's principal hematologic risk.

457. Affective flattening, alogia, avolition, and social withdrawal in schizophrenia are described as which symptom category, and why are they clinically important?
     • Positive symptoms; they respond rapidly to all antipsychotics
     • Negative symptoms; they often respond poorly to treatment and strongly affect function
     • Cognitive symptoms; they are unrelated to long-term outcome
     • Mood symptoms; they indicate an alternate diagnosis of depression

     Correct answer: Negative symptoms; they often respond poorly to treatment and strongly affect function

     Negative symptoms that respond poorly to treatment is correct because diminished emotional expression, alogia, and avolition tend to be less responsive to antipsychotics yet are major drivers of disability. They are not positive symptoms, are distinct from cognitive symptoms, and although they overlap superficially with depression they are a recognized core feature of schizophrenia rather than evidence of a different diagnosis.

458. A patient on a high-potency typical antipsychotic develops high fever, severe muscle rigidity, altered mental status, autonomic instability, and a markedly elevated creatine kinase. Which life-threatening reaction should be suspected?
     • Serotonin syndrome
     • Tardive dyskinesia
     • Neuroleptic malignant syndrome
     • Akathisia

     Correct answer: Neuroleptic malignant syndrome

     Neuroleptic malignant syndrome is correct because the tetrad of hyperthermia, lead-pipe rigidity, autonomic instability, and altered mental status with elevated creatine kinase following dopamine-blocking agents defines this emergency. Serotonin syndrome arises from serotonergic drugs and features clonus and hyperreflexia, tardive dyskinesia is a delayed movement disorder, and akathisia is motor restlessness without fever or rigidity.

459. A 9-year-old boy has a two-year history reported at home and school of difficulty sustaining attention, frequent careless mistakes, fidgeting, interrupting others, and inability to wait his turn. Which diagnosis best fits this presentation?
     • Oppositional defiant disorder
     • Conduct disorder
     • Autism spectrum disorder
     • Attention-deficit/hyperactivity disorder

     Correct answer: Attention-deficit/hyperactivity disorder

     Attention-deficit/hyperactivity disorder is correct because the combination of inattentive and hyperactive-impulsive symptoms present in more than one setting before age 12 and causing functional impairment defines ADHD. Oppositional defiant disorder centers on defiant and hostile behavior, conduct disorder involves violation of others' rights, and autism spectrum disorder features social communication deficits and restricted interests.

460. Which medication class is considered first-line pharmacotherapy for attention-deficit/hyperactivity disorder?
     • Stimulants such as methylphenidate and amphetamine formulations
     • Selective serotonin reuptake inhibitors
     • Benzodiazepines
     • Second-generation antipsychotics

     Correct answer: Stimulants such as methylphenidate and amphetamine formulations

     Stimulants are correct because methylphenidate and amphetamine-based agents are the most effective and first-line treatment for ADHD. SSRIs treat depression and anxiety, benzodiazepines are not indicated and may worsen attention, and second-generation antipsychotics are not first-line for ADHD.

461. A 10-year-old with ADHD also has a history of a tic disorder, and the family prefers to avoid stimulants. Which non-stimulant medication is an appropriate evidence-based alternative for ADHD?
     • Sertraline
     • Atomoxetine
     • Risperidone
     • Lorazepam

     Correct answer: Atomoxetine

     Atomoxetine is correct because this selective norepinephrine reuptake inhibitor is an established non-stimulant option for ADHD and is reasonable when stimulants are undesirable, such as with comorbid tics or concern about misuse. Sertraline treats anxiety and depression, risperidone is an antipsychotic, and lorazepam is a benzodiazepine, none of which are first-line ADHD treatments.

462. Before initiating stimulant therapy for ADHD, which aspect of the history is most important to assess because of a relevant safety concern?
     • History of seasonal allergies
     • History of childhood ear infections
     • Personal or family history of cardiac disease or sudden death
     • Dietary fiber intake

     Correct answer: Personal or family history of cardiac disease or sudden death

     Personal or family cardiac history is correct because stimulants increase heart rate and blood pressure, so a history of structural heart disease, arrhythmia, or sudden cardiac death warrants further cardiac evaluation before starting therapy. Seasonal allergies, prior ear infections, and dietary fiber intake do not bear on the cardiovascular safety of stimulants.

463. A 32-year-old combat veteran reports that for the past four months he has had recurrent nightmares and intrusive memories of an explosion, avoids crowds and reminders of the event, feels emotionally numb, and is hypervigilant with an exaggerated startle response. Which diagnosis best fits?
     • Acute stress disorder
     • Generalized anxiety disorder
     • Adjustment disorder
     • Posttraumatic stress disorder

     Correct answer: Posttraumatic stress disorder

     Posttraumatic stress disorder is correct because intrusion symptoms, avoidance, negative alterations in cognition and mood, and hyperarousal persisting longer than one month after a traumatic event define PTSD. Acute stress disorder applies when symptoms last three days to one month, generalized anxiety disorder lacks the trauma-linked re-experiencing, and adjustment disorder follows a non-traumatic stressor with less specific symptoms.

464. What minimum symptom duration distinguishes posttraumatic stress disorder from acute stress disorder?
     • Symptoms persisting more than 1 month
     • Symptoms persisting more than 1 week
     • Symptoms persisting more than 6 months
     • Symptoms persisting more than 1 year

     Correct answer: Symptoms persisting more than 1 month

     More than one month is correct because acute stress disorder covers trauma-related symptoms lasting three days to one month, whereas posttraumatic stress disorder is diagnosed when those symptoms persist beyond one month. One week, six months, and one year are not the dividing thresholds between these two diagnoses.

465. Which interventions are considered first-line for posttraumatic stress disorder?
     • Long-term benzodiazepine therapy alone
     • Trauma-focused psychotherapy and SSRIs or SNRIs
     • Typical antipsychotic monotherapy
     • Stimulant medication

     Correct answer: Trauma-focused psychotherapy and SSRIs or SNRIs

     Trauma-focused psychotherapy combined with SSRIs or SNRIs is correct because trauma-focused cognitive behavioral approaches and serotonergic antidepressants are the evidence-based first-line treatments for PTSD. Benzodiazepines are generally avoided because they do not treat core PTSD symptoms and carry dependence risk, while typical antipsychotics and stimulants are not first-line for PTSD.

466. A patient taking an SSRI is started on tramadol for pain and within hours develops agitation, diaphoresis, tremor, hyperreflexia, inducible clonus, and a temperature of 38.9 C. Which condition is most likely?
     • Neuroleptic malignant syndrome
     • Anticholinergic toxicity
     • Serotonin syndrome
     • Malignant hyperthermia

     Correct answer: Serotonin syndrome

     Serotonin syndrome is correct because the combination of two serotonergic agents producing autonomic instability, neuromuscular hyperexcitability with clonus and hyperreflexia, and altered mental status defines this reaction, which typically appears rapidly. Neuroleptic malignant syndrome develops more slowly with rigidity and hyporeflexia, anticholinergic toxicity causes dry skin and absent bowel sounds, and malignant hyperthermia is triggered by anesthetics.

467. A 17-year-old girl with severe distortion of body image restricts her intake, has a body mass index of 16, has missed menses, and is intensely fearful of gaining weight despite being underweight. Which diagnosis best fits?
     • Bulimia nervosa
     • Binge-eating disorder
     • Avoidant/restrictive food intake disorder
     • Anorexia nervosa

     Correct answer: Anorexia nervosa

     Anorexia nervosa is correct because restriction of intake leading to significantly low body weight, intense fear of weight gain, and disturbance in body image perception define this disorder. Bulimia nervosa involves binge eating with compensatory behaviors at normal or higher weight, binge-eating disorder lacks compensatory behaviors, and avoidant/restrictive food intake disorder lacks the weight-related fear and body image disturbance.

468. A patient with bulimia nervosa who engages in frequent self-induced vomiting is at greatest risk for which metabolic derangement?
     • Hypokalemic metabolic alkalosis
     • Hyperkalemic metabolic acidosis
     • Respiratory acidosis
     • Hypernatremia

     Correct answer: Hypokalemic metabolic alkalosis

     Hypokalemic metabolic alkalosis is correct because recurrent vomiting causes loss of gastric hydrogen and chloride along with potassium, producing low potassium and a metabolic alkalosis. Hyperkalemic metabolic acidosis, respiratory acidosis, and hypernatremia do not result from the loss of acidic gastric contents seen with purging.

469. A 40-year-old woman reports recurrent intrusive thoughts that her hands are contaminated, causing marked anxiety, and she washes her hands more than 50 times daily to relieve the distress, consuming hours of her day. Which diagnosis best fits?
     • Generalized anxiety disorder
     • Obsessive-compulsive disorder
     • Illness anxiety disorder
     • Specific phobia

     Correct answer: Obsessive-compulsive disorder

     Obsessive-compulsive disorder is correct because recurrent intrusive obsessions, such as contamination fears, paired with repetitive compulsions, such as excessive handwashing performed to reduce anxiety and consuming significant time, define OCD. Generalized anxiety disorder lacks discrete compulsions, illness anxiety disorder centers on fear of having a disease, and specific phobia is fear of a circumscribed trigger.

470. Which treatments are considered first-line for obsessive-compulsive disorder?
     • Benzodiazepines and supportive therapy
     • Lithium monotherapy
     • SSRIs and exposure and response prevention therapy
     • Stimulant medication

     Correct answer: SSRIs and exposure and response prevention therapy

     SSRIs combined with exposure and response prevention is correct because serotonergic antidepressants, often at higher doses than for depression, plus this specific form of cognitive behavioral therapy are the established first-line treatments for OCD. Benzodiazepines are not effective for core OCD symptoms, lithium is a mood stabilizer, and stimulants are not indicated.

471. A 68-year-old man with longstanding alcohol use is admitted and stops drinking abruptly. Forty-eight hours later he develops tremor, agitation, visual hallucinations, tachycardia, fever, and disorientation. Which condition is most likely?
     • Wernicke encephalopathy
     • Schizophrenia
     • Hepatic encephalopathy
     • Delirium tremens

     Correct answer: Delirium tremens

     Delirium tremens is correct because severe alcohol withdrawal with autonomic hyperactivity, hallucinations, and disorientation appearing roughly two to four days after cessation defines this life-threatening syndrome. Wernicke encephalopathy presents with confusion, ataxia, and ophthalmoplegia from thiamine deficiency, schizophrenia is a chronic primary psychotic disorder, and hepatic encephalopathy features asterixis and elevated ammonia without the withdrawal time course.

472. Which medication class is first-line to manage the symptoms of and prevent complications from alcohol withdrawal?
     • Benzodiazepines
     • Beta-blockers
     • Antipsychotics
     • Opioids

     Correct answer: Benzodiazepines

     Benzodiazepines are correct because they treat alcohol withdrawal by enhancing GABA activity, reducing the risk of seizures and progression to delirium tremens. Beta-blockers may blunt autonomic signs but do not prevent seizures, antipsychotics lower the seizure threshold and do not address the underlying mechanism, and opioids are not used for withdrawal.

473. A 75-year-old hospitalized woman develops acute onset of fluctuating confusion, inattention, and disorganized thinking over hours, with a worsening course at night. Which feature most distinguishes delirium from dementia?
     • Gradual, progressive decline over years
     • Acute onset with fluctuating course and impaired attention
     • Preserved attention with isolated memory loss
     • Stable cognition unaffected by medical illness

     Correct answer: Acute onset with fluctuating course and impaired attention

     Acute onset with fluctuating course and impaired attention is correct because delirium is defined by an acute, often reversible disturbance of attention and awareness that waxes and wanes and is precipitated by a medical condition. Gradual decline over years, preserved attention, and cognition unaffected by illness are features of dementia rather than delirium.

474. A 14-year-old girl is brought in after intentionally taking an overdose of acetaminophen following an argument. After medical stabilization, which assessment is the most important next step in her psychiatric evaluation?
     • Reassure her and discharge home immediately
     • Begin a stimulant for presumed ADHD
     • Assess ongoing suicide risk and ensure a safe disposition
     • Defer all psychiatric evaluation for one month

     Correct answer: Assess ongoing suicide risk and ensure a safe disposition

     Assessing ongoing suicide risk and ensuring a safe disposition is correct because a deliberate self-harm attempt requires a structured evaluation of intent, plan, and protective factors to determine the appropriate level of care. Immediate discharge ignores ongoing risk, starting a stimulant is not indicated, and deferring evaluation leaves an at-risk patient unprotected.

475. A 36-year-old woman has long-standing fear of being scrutinized or embarrassed in social and performance situations, leading her to avoid meetings and public speaking, which impairs her career. Which diagnosis best fits?
     • Agoraphobia
     • Panic disorder
     • Schizoid personality disorder
     • Social anxiety disorder

     Correct answer: Social anxiety disorder

     Social anxiety disorder is correct because marked fear of social or performance situations due to possible scrutiny or embarrassment, with avoidance and functional impairment, defines this condition. Agoraphobia involves fear of situations where escape is difficult, panic disorder centers on recurrent unexpected attacks, and schizoid personality disorder reflects a pervasive lack of desire for social relationships rather than fear of them.

476. A 6-year-old boy with persistent deficits in social communication, limited eye contact, restricted repetitive behaviors, and intense fixated interests since early childhood is being evaluated. Which diagnosis best fits this presentation?
     • Autism spectrum disorder
     • Attention-deficit/hyperactivity disorder
     • Intellectual disability alone
     • Selective mutism

     Correct answer: Autism spectrum disorder

     Autism spectrum disorder is correct because persistent deficits in social communication and interaction together with restricted, repetitive patterns of behavior and interests with early childhood onset define this diagnosis. ADHD centers on inattention and hyperactivity, intellectual disability alone does not require the social communication and repetitive behavior pattern, and selective mutism is a failure to speak in specific situations only.

477. A patient with major depressive disorder has not responded to an adequate trial of a first SSRI at therapeutic dose for eight weeks. Which step is the most appropriate next action?
     • Conclude the patient cannot be treated and stop therapy
     • Switch to a different antidepressant or augment, after confirming adherence and adequate trial
     • Add a benzodiazepine as definitive monotherapy
     • Immediately refer for electroconvulsive therapy without other steps

     Correct answer: Switch to a different antidepressant or augment, after confirming adherence and adequate trial

     Switching antidepressants or augmenting after confirming adherence and an adequate trial is correct because an inadequate response to a first agent warrants verifying the dose and duration and then either changing agents or adding an augmenting medication. Stopping all therapy abandons treatable illness, a benzodiazepine does not treat depression, and electroconvulsive therapy is reserved for severe or refractory cases after standard steps.

478. A patient who abruptly stops a short half-life SSRI such as paroxetine reports dizziness, flu-like symptoms, irritability, and electric-shock sensations. Which phenomenon best explains these symptoms, and how is it best prevented?
     • Serotonin syndrome; prevented by adding a second serotonergic drug
     • Anticholinergic withdrawal; prevented by abrupt cessation
     • Antidepressant discontinuation syndrome; prevented by tapering the dose gradually
     • A new manic episode; prevented by stopping all medication

     Correct answer: Antidepressant discontinuation syndrome; prevented by tapering the dose gradually

     Antidepressant discontinuation syndrome prevented by gradual tapering is correct because abruptly stopping a short half-life SSRI causes flu-like symptoms, dizziness, and sensory disturbances that are avoided by slowly reducing the dose. It is not serotonin syndrome, which results from excess serotonergic activity, is not anticholinergic withdrawal, and is not a manic episode.

479. A 70-year-old man with no prior psychiatric history develops progressive memory loss over two years, difficulty managing finances, and trouble naming objects, with intact alertness and attention early in the course. Which condition best explains this presentation?
     • Delirium
     • Brief psychotic disorder
     • Generalized anxiety disorder
     • Major neurocognitive disorder (dementia)

     Correct answer: Major neurocognitive disorder (dementia)

     Major neurocognitive disorder is correct because a gradual, progressive decline in memory and other cognitive domains over years with preserved early attention and alertness characterizes dementia. Delirium has an acute fluctuating course with impaired attention, brief psychotic disorder involves transient psychosis lasting under a month, and generalized anxiety disorder does not cause progressive cognitive decline.

480. A 47-year-old man develops an area of spreading redness, warmth, and tenderness on the dorsum of his foot after a small abrasion. There is no abscess, no purulent drainage, and the borders are flat and indistinct. Which finding would most strongly favor cellulitis over a noninfectious mimic such as stasis dermatitis?
     • Symmetric involvement of both lower legs
     • Chronic bilateral hyperpigmentation and scaling
     • Acute unilateral involvement with fever and rapidly advancing erythema
     • Pruritus without warmth or tenderness

     Correct answer: Acute unilateral involvement with fever and rapidly advancing erythema

     Acute, unilateral, rapidly advancing erythema accompanied by fever favors cellulitis, because true bacterial cellulitis is typically a unilateral, acute, warm, tender process with systemic signs. Symmetric bilateral involvement, chronic hyperpigmentation with scaling, and pruritus without warmth are hallmarks of stasis dermatitis, a common noninfectious mimic that is frequently misdiagnosed and overtreated with antibiotics.

481. A 62-year-old woman with well-controlled diabetes is diagnosed with nonpurulent cellulitis of the lower leg. She is hemodynamically stable, tolerating oral intake, and has no signs of systemic toxicity. Which management plan is most appropriate?
     • Admit for intravenous vancomycin
     • Outpatient oral antibiotic targeting streptococci, such as cephalexin, with elevation and follow-up
     • Topical mupirocin alone
     • No antibiotics, with compression stockings only

     Correct answer: Outpatient oral antibiotic targeting streptococci, such as cephalexin, with elevation and follow-up

     Outpatient oral therapy directed at streptococci, such as cephalexin, with limb elevation and follow-up is appropriate, because uncomplicated nonpurulent cellulitis in a stable patient without systemic toxicity can be managed orally on an outpatient basis. Intravenous vancomycin and admission are reserved for systemic toxicity or failure of oral therapy, topical mupirocin treats impetigo rather than cellulitis, and withholding antibiotics undertreats an active bacterial infection.

482. A 55-year-old man presents with a painful red leg and is diagnosed with cellulitis. Which feature should prompt the clinician to broaden empiric coverage to include methicillin-resistant Staphylococcus aureus?
     • Flat, nonpurulent erythema without drainage
     • Mild localized warmth with no fluctuance
     • Erythema that began at a site of chronic venous stasis
     • Presence of purulent drainage or a drainable abscess

     Correct answer: Presence of purulent drainage or a drainable abscess

     Purulent drainage or a drainable abscess should prompt coverage for methicillin-resistant Staphylococcus aureus, because purulent skin and soft-tissue infections are most often caused by community-acquired MRSA. Flat nonpurulent erythema, mild warmth without fluctuance, and stasis-associated changes point toward streptococcal nonpurulent disease, for which beta-lactam therapy targeting streptococci is sufficient.

483. A 40-year-old woman develops a sharply demarcated, raised, fiery-red plaque on her cheek with a well-defined advancing border, accompanied by fever and chills. The lesion is warm and tender with a clear edge separating it from normal skin. Which superficial skin infection is most consistent with these findings?
     • Erysipelas
     • Deep necrotizing fasciitis
     • Contact dermatitis
     • Tinea faciei

     Correct answer: Erysipelas

     Erysipelas is most consistent with a sharply demarcated, raised, fiery-red facial plaque with a clearly defined advancing border and systemic symptoms, because erysipelas involves the superficial dermis and lymphatics and is usually caused by beta-hemolytic streptococci. Necrotizing fasciitis causes pain out of proportion with poorly defined borders, contact dermatitis is pruritic rather than febrile, and tinea faciei produces an annular scaling plaque rather than an acute raised hot lesion.

484. A 34-year-old man who removed an engorged tick from his groin one month ago in Massachusetts now has palpitations and lightheadedness. An electrocardiogram shows third-degree atrioventricular block. He recalls a transient circular rash weeks earlier. Which infection most likely explains his cardiac findings?
     • Acute rheumatic fever
     • Lyme carditis
     • Viral myocarditis from influenza
     • Chagas disease

     Correct answer: Lyme carditis

     Lyme carditis best explains high-grade atrioventricular block in a patient with a prior erythema migrans rash and tick exposure in an endemic region, because disseminated Lyme disease characteristically causes conduction abnormalities, most often varying degrees of AV block. Acute rheumatic fever follows streptococcal pharyngitis, influenza myocarditis is not linked to a target rash, and Chagas disease occurs after exposure to triatomine bugs in endemic areas of Latin America.

485. A 45-year-old gardener in an endemic area presents with several weeks of an intermittently swollen, painful right knee. He has no recollection of a rash but spends extensive time outdoors. Two-tier serologic testing for Lyme disease is positive. Which manifestation does this presentation represent?
     • Early localized Lyme disease
     • Reactive arthritis
     • Late Lyme arthritis
     • Septic arthritis from Staphylococcus aureus

     Correct answer: Late Lyme arthritis

     Late Lyme arthritis is represented by an intermittently swollen, painful large joint such as the knee weeks to months after exposure with positive two-tier serology, because untreated Lyme disease can progress to a mono- or oligoarticular arthritis, most often of the knee. Early localized disease features erythema migrans, reactive arthritis follows enteric or genitourinary infection, and staphylococcal septic arthritis is acute and purulent rather than intermittent.

486. A 28-year-old hiker removes an attached deer tick that has been on his skin for roughly 18 hours. He lives in a highly Lyme-endemic county and the tick appears engorged. Regarding prevention of Lyme disease, which statement reflects appropriate counseling?
     • A single dose of doxycycline prophylaxis may be considered for an identified Ixodes tick attached at least 36 hours in a highly endemic area
     • A full 21-day course of amoxicillin should be given to every patient with any tick bite
     • Prophylaxis is never indicated regardless of circumstances
     • Intravenous ceftriaxone should be given immediately after any tick removal

     Correct answer: A single dose of doxycycline prophylaxis may be considered for an identified Ixodes tick attached at least 36 hours in a highly endemic area

     A single dose of doxycycline prophylaxis may be considered when an identified Ixodes tick has been attached for at least 36 hours in a highly endemic area, because the risk of transmission rises with prolonged attachment and post-exposure prophylaxis can prevent infection in that setting. A full treatment course for every tick bite, never offering prophylaxis, and routine intravenous therapy after any bite all misapply the targeted criteria for prophylaxis.

487. A 33-year-old healthy man presents 30 hours after sudden onset of fever, chills, diffuse myalgias, headache, and a nonproductive cough during peak influenza season. A rapid molecular influenza test is positive for influenza A. He has no comorbidities. Which statement best guides antiviral therapy?
     • Antivirals are contraindicated in healthy adults
     • Oseltamivir is most beneficial when started within 48 hours of symptom onset
     • Antibiotics should be started instead of antivirals
     • Antivirals should be withheld until a chest radiograph is obtained

     Correct answer: Oseltamivir is most beneficial when started within 48 hours of symptom onset

     Oseltamivir is most beneficial when started within 48 hours of symptom onset, because early neuraminidase inhibitor therapy shortens illness duration and reduces complications, and this patient is well within that window. Antivirals are not contraindicated in healthy adults, antibiotics do not treat an uncomplicated viral infection, and an uncomplicated influenza diagnosis does not require a chest radiograph before initiating antiviral treatment.

488. A clinic is planning its annual influenza vaccination campaign. Which patient has a true contraindication to receiving the live attenuated intranasal influenza vaccine and should instead receive the inactivated injectable vaccine?
     • A healthy 22-year-old graduate student
     • A healthy 35-year-old nurse
     • A 6-year-old with poorly controlled asthma
     • A healthy 18-year-old athlete

     Correct answer: A 6-year-old with poorly controlled asthma

     A child with poorly controlled asthma should receive the inactivated injectable vaccine rather than the live attenuated intranasal product, because the live vaccine is avoided in those with reactive airway disease and certain immunocompromising conditions due to the risk of wheezing. The healthy nonpregnant young adults listed have no contraindication and may receive either formulation, making the asthmatic child the appropriate exception.

489. A 78-year-old nursing home resident with chronic obstructive pulmonary disease develops fever, worsening cough, and hypoxia 24 hours after onset of influenza-like illness. A rapid test confirms influenza. Which feature of this case most strongly justifies antiviral treatment even though more than two days might elapse before therapy?
     • Her preference to avoid hospitalization
     • The fact that she is fully vaccinated
     • The absence of fever on arrival
     • Her age and high-risk comorbidity with progressive lower respiratory involvement

     Correct answer: Her age and high-risk comorbidity with progressive lower respiratory involvement

     Advanced age combined with a high-risk comorbidity and progressive lower respiratory involvement most strongly justifies antiviral treatment, because patients at high risk for complications benefit from neuraminidase inhibitors even when therapy begins beyond the usual 48-hour window. Patient preference to avoid hospitalization, prior vaccination, and absence of fever do not override the indication to treat severe or progressive influenza in a high-risk host.

490. A 26-year-old previously healthy woman presents on day two of confirmed influenza with fever, myalgias, and cough but normal vital signs, normal oxygenation, and no comorbidities. Which is the most appropriate overall management approach?
     • Empiric broad-spectrum antibiotics plus admission
     • Immediate corticosteroids to blunt the inflammatory response
     • Supportive care with antipyretics and hydration, with consideration of oseltamivir given the early presentation
     • Prophylactic anticoagulation for all influenza patients

     Correct answer: Supportive care with antipyretics and hydration, with consideration of oseltamivir given the early presentation

     Supportive care with antipyretics and hydration, with consideration of oseltamivir given the early presentation, is the most appropriate approach, because uncomplicated influenza in a low-risk patient is managed symptomatically and early antiviral therapy may modestly shorten illness. Empiric antibiotics, routine corticosteroids, and prophylactic anticoagulation are not indicated for uncomplicated influenza and expose the patient to unnecessary harm.

491. A 71-year-old man with diabetes presents with fever, flank pain, and confusion two days after dysuria began. Vital signs show temperature 39.2 C, heart rate 118, respiratory rate 26, and blood pressure 84/50. After a fluid bolus the blood pressure remains 82/48 and the serum lactate is 4.5 mmol/L. Which condition does this presentation most accurately represent?
     • Uncomplicated urinary tract infection
     • Systemic inflammatory response without infection
     • Dehydration without infection
     • Septic shock from a urinary source

     Correct answer: Septic shock from a urinary source

     Septic shock from a urinary source is most accurate, because the patient has a documented infection with persistent hypotension requiring more than fluids and an elevated lactate despite adequate resuscitation, which defines septic shock. An uncomplicated urinary tract infection does not cause hypotension and lactic acidosis, the inflammatory response here is clearly infection-driven, and simple dehydration would not produce this degree of refractory hypotension with elevated lactate.

492. A 60-year-old woman is admitted with suspected sepsis from pneumonia. According to current sepsis bundles, which sequence of first-hour interventions is most appropriate after recognizing sepsis?
     • Wait for blood culture results, then start narrow antibiotics
     • Obtain blood cultures, measure lactate, start broad-spectrum antibiotics, and begin crystalloid resuscitation
     • Start oral antibiotics and arrange outpatient follow-up
     • Administer vasopressors before any fluids or antibiotics

     Correct answer: Obtain blood cultures, measure lactate, start broad-spectrum antibiotics, and begin crystalloid resuscitation

     Obtaining blood cultures, measuring lactate, starting broad-spectrum antibiotics, and beginning crystalloid resuscitation is the appropriate first-hour sequence, because early cultures, lactate assessment, prompt empiric antibiotics, and fluid resuscitation are the core bundle elements that improve survival. Waiting for cultures delays therapy, oral antibiotics with discharge undertreat sepsis, and vasopressors are added only after adequate fluid resuscitation in persistent hypotension.

493. A clinician is using the quick Sequential Organ Failure Assessment (qSOFA) score to identify patients with suspected infection who are at higher risk of poor outcomes. Which combination of findings represents a positive qSOFA score?
     • Heart rate 70, temperature 37.0 C, and normal mentation
     • White blood cell count 15,000 alone
     • Respiratory rate 22, systolic blood pressure 95, and altered mental status
     • Oxygen saturation 97% with normal blood pressure and mentation

     Correct answer: Respiratory rate 22, systolic blood pressure 95, and altered mental status

     A respiratory rate of at least 22, systolic blood pressure of 100 or less, and altered mental status are the three qSOFA criteria, and meeting at least two identifies patients with suspected infection at higher risk of mortality. A normal heart rate and mentation, an isolated leukocytosis, and normal oxygenation with normal blood pressure and mentation do not satisfy the qSOFA criteria used for risk stratification.

494. A 36-year-old man is diagnosed with HIV during routine screening. His initial CD4 count is 540 cells/microliter and he is asymptomatic. He asks when he should begin treatment. Which recommendation is most consistent with current guidelines?
     • Defer antiretroviral therapy until the CD4 count falls below 350
     • Begin therapy only if an opportunistic infection develops
     • Begin therapy only if the viral load exceeds 100,000 copies
     • Begin antiretroviral therapy as soon as possible regardless of CD4 count

     Correct answer: Begin antiretroviral therapy as soon as possible regardless of CD4 count

     Beginning antiretroviral therapy as soon as possible regardless of CD4 count is consistent with current guidelines, because early treatment improves survival, preserves immune function, and reduces transmission for all patients with HIV. Deferring until the CD4 count drops, waiting for an opportunistic infection, and waiting for a high viral load reflect outdated thresholds that allow preventable immune injury and ongoing transmission.

495. A 29-year-old man with advanced HIV and a CD4 count of 90 cells/microliter presents with several weeks of progressive dyspnea on exertion, dry cough, and a markedly elevated lactate dehydrogenase. A chest radiograph shows diffuse bilateral interstitial infiltrates. Which opportunistic infection is most likely?
     • Bacterial lobar pneumonia
     • Pneumocystis jirovecii pneumonia
     • Pulmonary tuberculosis with a cavitary lesion
     • Influenza pneumonia

     Correct answer: Pneumocystis jirovecii pneumonia

     Pneumocystis jirovecii pneumonia is most likely, because in a patient with a CD4 count below 200 the combination of subacute exertional dyspnea, dry cough, diffuse bilateral interstitial infiltrates, and an elevated lactate dehydrogenase is classic. Bacterial lobar pneumonia presents acutely with focal consolidation, tuberculosis typically causes cavitary upper-lobe disease, and influenza pneumonia is acute and seasonal rather than subacute with this radiographic pattern.

496. A 31-year-old HIV-negative man requests a way to reduce his risk of acquiring HIV because he has an HIV-positive partner with a detectable viral load. He has no contraindications. Which preventive strategy is most appropriate?
     • A single dose of an antibiotic before each exposure
     • Annual HIV testing alone with no medication
     • Daily oral pre-exposure prophylaxis with tenofovir-based antiretrovirals
     • A 28-day antiretroviral course started only after a suspected exposure

     Correct answer: Daily oral pre-exposure prophylaxis with tenofovir-based antiretrovirals

     Daily oral pre-exposure prophylaxis with a tenofovir-based regimen is most appropriate, because it substantially reduces the risk of acquiring HIV in individuals at ongoing high risk, such as those with a serodiscordant partner. A pre-exposure antibiotic does not prevent HIV, testing alone offers no protection, and a 28-day post-exposure course addresses a discrete past exposure rather than ongoing risk reduction.

497. A 44-year-old woman with HIV has been on antiretroviral therapy for one year. Which laboratory result best indicates that her treatment is effectively controlling the infection?
     • A rising HIV RNA viral load
     • A falling CD4 count with a stable viral load
     • An undetectable or suppressed HIV RNA viral load with a rising CD4 count
     • A positive HIV antibody test

     Correct answer: An undetectable or suppressed HIV RNA viral load with a rising CD4 count

     An undetectable or suppressed HIV RNA viral load with a rising CD4 count best indicates effective treatment, because viral suppression is the primary goal of therapy and immune recovery is reflected by rising CD4 counts. A rising viral load suggests treatment failure or nonadherence, a falling CD4 count signals worsening immune status, and a positive antibody test merely confirms prior infection rather than treatment response.

498. A 26-year-old emergency department worker sustains a needlestick from a hollow-bore needle used on a patient whose HIV status is unknown but who has risk factors. The exposure occurred 90 minutes ago. Which action is most appropriate regarding HIV post-exposure prophylaxis?
     • Wait three months to test the worker before deciding on any therapy
     • Provide no prophylaxis because the source patient is not confirmed positive
     • Begin lifelong antiretroviral therapy immediately as if infected
     • Initiate a recommended antiretroviral post-exposure prophylaxis regimen as soon as possible, ideally within hours

     Correct answer: Initiate a recommended antiretroviral post-exposure prophylaxis regimen as soon as possible, ideally within hours

     Initiating a recommended antiretroviral post-exposure prophylaxis regimen as soon as possible, ideally within hours, is most appropriate, because prophylaxis is most effective when started early after a significant occupational exposure and source-patient testing is pursued in parallel. Waiting months forgoes the prophylaxis window, withholding therapy because the source is unconfirmed ignores risk-based guidance, and lifelong therapy is not indicated absent established infection.

499. A 23-year-old sexually active nonpregnant woman presents with two days of dysuria, urinary frequency, and urgency without fever, flank pain, or vaginal discharge. Which approach to diagnosis and treatment of this uncomplicated cystitis is most appropriate?
     • Obtain a CT urogram before any treatment
     • Require a positive blood culture before treating
     • Treat empirically based on the classic symptom pattern, often without a culture, using a first-line agent such as nitrofurantoin
     • Treat only after a 30-day observation period

     Correct answer: Treat empirically based on the classic symptom pattern, often without a culture, using a first-line agent such as nitrofurantoin

     Empiric treatment based on the classic symptom pattern, often without a culture, using a first-line agent such as nitrofurantoin is most appropriate, because uncomplicated cystitis in an otherwise healthy nonpregnant woman can be diagnosed clinically and treated empirically. A CT urogram, blood cultures, and prolonged observation are unnecessary and delay relief of a straightforward lower urinary tract infection.

500. A 67-year-old man with an indwelling urinary catheter has a urine culture showing 100,000 colony-forming units per milliliter of Escherichia coli. He is afebrile, has no suprapubic or flank pain, and feels well. What is the most appropriate management of this finding?
     • Treat with a 14-day course of ciprofloxacin
     • Do not treat, because asymptomatic bacteriuria in a catheterized patient generally should not be treated
     • Replace the catheter and immediately start intravenous antibiotics
     • Treat with single-dose fosfomycin to prevent future infection

     Correct answer: Do not treat, because asymptomatic bacteriuria in a catheterized patient generally should not be treated

     Not treating is most appropriate, because asymptomatic bacteriuria in a catheterized patient generally should not be treated, as antibiotics promote resistance and adverse effects without clinical benefit. Treating with prolonged ciprofloxacin, starting intravenous antibiotics, or giving single-dose therapy all overtreat colonization; antibiotics are reserved for symptomatic catheter-associated infection rather than incidental bacteriuria.

501. A 30-year-old woman presents with two days of fever to 39 C, right flank pain, costovertebral angle tenderness, nausea, and dysuria. She is hemodynamically stable and able to tolerate oral fluids. Urinalysis shows pyuria and bacteriuria. Which diagnosis and initial management are most appropriate?
     • Uncomplicated cystitis treated with a 3-day course of nitrofurantoin
     • Bacterial vaginosis treated with oral metronidazole
     • Acute pyelonephritis treated with an appropriate fluoroquinolone or other guideline-concordant agent and a longer course
     • Urethritis treated with topical estrogen

     Correct answer: Acute pyelonephritis treated with an appropriate fluoroquinolone or other guideline-concordant agent and a longer course

     Acute pyelonephritis treated with a guideline-concordant agent such as a fluoroquinolone for a longer course is most appropriate, because fever, flank pain, and costovertebral angle tenderness with pyuria indicate upper tract infection requiring more aggressive and prolonged therapy than cystitis. Nitrofurantoin does not achieve adequate renal tissue levels for pyelonephritis, and bacterial vaginosis and urethritis do not explain the flank findings and fever.

502. A 19-year-old college student living in a dormitory presents with a 12-hour history of fever, severe headache, photophobia, and neck stiffness, and now has a rapidly spreading petechial rash. Which intervention is the highest immediate priority?
     • Outpatient referral for elective lumbar puncture
     • Oral antibiotics with discharge and next-day recheck
     • Reassurance and symptomatic treatment for a viral syndrome
     • Immediate empiric intravenous antibiotics for bacterial meningitis without delay for imaging

     Correct answer: Immediate empiric intravenous antibiotics for bacterial meningitis without delay for imaging

     Immediate empiric intravenous antibiotics without delay for imaging is the highest priority, because fever, headache, neck stiffness, and a petechial rash suggest meningococcal meningitis, a rapidly fatal emergency in which prompt antibiotics improve survival. Elective outpatient evaluation, oral antibiotics with discharge, and reassurance for a presumed viral illness all dangerously postpone treatment of a life-threatening bacterial central nervous system infection.

503. A 25-year-old patient with suspected meningitis undergoes lumbar puncture. The cerebrospinal fluid shows a lymphocytic pleocytosis, normal glucose, and only mildly elevated protein, and Gram stain is negative. The patient is well-appearing and hemodynamically stable. Which diagnosis is most consistent with this profile?
     • Acute bacterial meningitis
     • Viral (aseptic) meningitis
     • Tuberculous meningitis with very low glucose
     • Fungal meningitis with eosinophils

     Correct answer: Viral (aseptic) meningitis

     Viral, or aseptic, meningitis is most consistent with a lymphocytic pleocytosis, normal glucose, mildly elevated protein, and a negative Gram stain in a well-appearing patient, because viral infection provokes a lymphocytic response without consuming glucose. Bacterial meningitis produces neutrophilic pleocytosis with low glucose, tuberculous meningitis causes very low glucose with high protein, and fungal disease may show eosinophils, none of which match this benign profile.

504. A 21-year-old man presents with painful grouped vesicles on an erythematous base on the penile shaft, preceded by a day of localized burning and tingling. Tender inguinal lymphadenopathy is present. This is his first such episode. Which treatment is most appropriate?
     • Intramuscular benzathine penicillin G
     • Oral valacyclovir for the initial outbreak
     • Oral metronidazole
     • Topical permethrin

     Correct answer: Oral valacyclovir for the initial outbreak

     Oral valacyclovir for the initial outbreak is most appropriate, because painful grouped vesicles with a tingling prodrome are characteristic of genital herpes simplex virus, and nucleoside analogue antivirals shorten the outbreak and reduce viral shedding. Benzathine penicillin treats syphilis, metronidazole treats trichomoniasis or bacterial vaginosis, and permethrin treats scabies, none of which cause the described vesicular herpetic lesions.

505. A 58-year-old immunocompetent adult presents with a painful, unilateral vesicular rash in a single thoracic dermatomal band that does not cross the midline, with pain that preceded the rash by two days. He presents within 48 hours of rash onset. Which intervention is most appropriate?
     • Oral amoxicillin for presumed bacterial infection
     • Topical antifungal cream alone
     • Oral antiviral therapy such as valacyclovir to reduce acute pain and the risk of postherpetic neuralgia
     • No treatment, as antivirals provide no benefit at any time

     Correct answer: Oral antiviral therapy such as valacyclovir to reduce acute pain and the risk of postherpetic neuralgia

     Oral antiviral therapy such as valacyclovir is most appropriate, because a painful unilateral dermatomal vesicular eruption is herpes zoster from reactivation of varicella-zoster virus, and antivirals started within 72 hours reduce acute pain and the risk of postherpetic neuralgia. Amoxicillin treats bacteria, topical antifungals do not address viral replication, and antiviral therapy clearly provides benefit when started early.

506. A 27-year-old man with a new sexual partner has a single, painless genital ulcer with a clean base and firm, indurated borders, along with painless rubbery inguinal lymphadenopathy. Which test is most appropriate to confirm the suspected diagnosis?
     • Wet mount for motile trichomonads
     • KOH preparation of the lesion
     • Tzanck smear of the ulcer base
     • Nontreponemal serologic testing such as RPR, confirmed with a treponemal test

     Correct answer: Nontreponemal serologic testing such as RPR, confirmed with a treponemal test

     Nontreponemal serologic testing such as RPR, confirmed with a treponemal-specific test, is most appropriate, because a painless indurated chancre with painless lymphadenopathy is characteristic of primary syphilis caused by Treponema pallidum. A wet mount evaluates trichomoniasis, a KOH preparation evaluates fungal infection, and a Tzanck smear evaluates herpetic vesicles, none of which diagnose the syphilitic chancre.

507. A 19-year-old sexually active woman is diagnosed with chlamydial cervicitis by nucleic acid amplification testing; gonorrhea testing is negative. She is not pregnant. Which treatment is most appropriate for uncomplicated genital chlamydia?
     • Oral doxycycline for seven days
     • A single dose of oral fluconazole
     • Topical clotrimazole
     • Intramuscular benzathine penicillin

     Correct answer: Oral doxycycline for seven days

     Oral doxycycline for seven days is the preferred regimen for uncomplicated genital chlamydia in a nonpregnant patient, because it provides reliable eradication of Chlamydia trachomatis. Fluconazole and clotrimazole treat candidiasis, and benzathine penicillin treats syphilis, none of which address a chlamydial infection. Partner treatment and retesting recommendations also accompany appropriate antibiotic therapy.

508. A 24-year-old sexually active woman presents with lower abdominal pain, cervical motion tenderness, adnexal tenderness, and mucopurulent cervical discharge. She is afebrile and able to tolerate oral intake, with no tubo-ovarian abscess on examination. Which diagnosis and management are most appropriate?
     • Uncomplicated cystitis treated with nitrofurantoin
     • Pelvic inflammatory disease treated with intramuscular ceftriaxone plus oral doxycycline and metronidazole
     • Vulvovaginal candidiasis treated with topical clotrimazole
     • Bacterial vaginosis treated with oral metronidazole alone

     Correct answer: Pelvic inflammatory disease treated with intramuscular ceftriaxone plus oral doxycycline and metronidazole

     Pelvic inflammatory disease treated with intramuscular ceftriaxone plus oral doxycycline and metronidazole is most appropriate, because lower abdominal pain with cervical motion tenderness and adnexal tenderness in a sexually active woman meets clinical criteria for pelvic inflammatory disease requiring broad coverage of gonorrhea, chlamydia, and anaerobes. Cystitis, candidiasis, and bacterial vaginosis do not explain the pelvic examination findings.

509. A 35-year-old woman is hospitalized and treated with clindamycin for a soft-tissue infection. Ten days later she develops profuse watery diarrhea, lower abdominal cramping, leukocytosis, and a low-grade fever. Which next step is most appropriate?
     • Continue clindamycin and add loperamide
     • Test the stool for Clostridioides difficile and initiate oral vancomycin or fidaxomicin
     • Proceed directly to urgent colectomy
     • Start oral fluconazole for fungal colitis

     Correct answer: Test the stool for Clostridioides difficile and initiate oral vancomycin or fidaxomicin

     Testing the stool for Clostridioides difficile and initiating oral vancomycin or fidaxomicin is most appropriate, because new watery diarrhea after recent antibiotic exposure, particularly clindamycin, strongly suggests C. difficile infection, and the inciting antibiotic should be stopped. Continuing clindamycin with an antimotility agent can precipitate toxic megacolon, urgent colectomy is reserved for fulminant disease, and fluconazole does not treat this bacterial colitis.

510. A 42-year-old man returns from a two-week trip to rural West Africa and presents one week later with paroxysms of high fever and shaking chills, headache, and jaundice. He took no chemoprophylaxis. Giemsa-stained blood smears confirm Plasmodium falciparum. Which feature most strongly indicates severe malaria requiring parenteral therapy?
     • Mild headache alone
     • A single low-grade fever spike
     • Impaired consciousness, high parasitemia, and acidosis
     • Resolution of fever after acetaminophen

     Correct answer: Impaired consciousness, high parasitemia, and acidosis

     Impaired consciousness, high parasitemia, and acidosis most strongly indicate severe malaria requiring parenteral therapy such as intravenous artesunate, because Plasmodium falciparum can cause cerebral involvement, end-organ dysfunction, and metabolic derangement that mandate aggressive treatment. A mild isolated headache, a single low-grade fever, and symptomatic improvement with antipyretics do not signify the severe disease criteria that change management.

511. A 30-year-old man steps on a nail through his shoe and sustains a deep puncture wound. He completed his childhood vaccinations but cannot recall his last tetanus booster, and it has likely been over 10 years. The wound is contaminated with soil. Which tetanus prophylaxis is most appropriate?
     • No prophylaxis, because he completed his childhood series
     • Tetanus immune globulin alone, without any toxoid
     • A full primary three-dose series given over the next month
     • Tetanus-containing toxoid booster, because the wound is dirty and his last dose was more than five years ago

     Correct answer: Tetanus-containing toxoid booster, because the wound is dirty and his last dose was more than five years ago

     A tetanus-containing toxoid booster is most appropriate, because for a dirty or contaminated wound in a fully immunized patient whose last dose was more than five years ago, a booster is indicated, whereas immune globulin is reserved for those with an unknown or incomplete primary series. Withholding prophylaxis, giving immune globulin alone, or restarting a primary series misapplies the wound-management criteria for a previously vaccinated patient.

512. A 5-year-old unvaccinated child presents with several days of cough, coryza, and conjunctivitis followed by a maculopapular rash beginning at the hairline and spreading downward. Tiny bluish-white spots with red halos are seen on the buccal mucosa. Beyond supportive care, which intervention is recommended for this measles infection?
     • Vitamin A supplementation
     • Oral acyclovir
     • Intramuscular benzathine penicillin
     • Systemic corticosteroids as primary therapy

     Correct answer: Vitamin A supplementation

     Vitamin A supplementation is recommended in addition to supportive care, because it reduces morbidity and mortality in children with measles, which is identified here by the three Cs of cough, coryza, and conjunctivitis with pathognomonic Koplik spots preceding a cephalocaudal rash. Acyclovir targets herpesviruses, penicillin treats bacterial infection, and corticosteroids are not primary therapy for uncomplicated measles.

513. A 30-year-old healthcare worker has a positive interferon-gamma release assay during routine screening but is asymptomatic. A chest radiograph is normal, and she has no cough, fever, or weight loss. Which diagnosis and management are most appropriate?
     • Active pulmonary tuberculosis requiring four-drug therapy
     • Latent tuberculosis infection treated with a recommended regimen such as isoniazid plus rifapentine
     • No infection, because the chest radiograph is normal
     • Active tuberculosis treated with a single antibiotic

     Correct answer: Latent tuberculosis infection treated with a recommended regimen such as isoniazid plus rifapentine

     Latent tuberculosis infection treated with a recommended regimen such as isoniazid plus rifapentine is most appropriate, because a positive interferon-gamma release assay with no symptoms and a normal chest radiograph indicates latent rather than active disease, and treating latent infection prevents progression to active tuberculosis. Active disease requires multidrug therapy and is unlikely without symptoms or radiographic findings, and a positive test indicates infection despite a normal film.

514. A 48-year-old man with poorly controlled diabetes develops, over hours, a dusky area of skin with severe pain out of proportion to the examination, crepitus on palpation, bullae, and rapidly progressing systemic toxicity with hypotension. Which management is most appropriate?
     • Discharge on oral antibiotics with next-day follow-up
     • Topical antibiotic ointment with warm compresses
     • Emergent surgical exploration and debridement with broad-spectrum intravenous antibiotics
     • Outpatient antifungal therapy and observation

     Correct answer: Emergent surgical exploration and debridement with broad-spectrum intravenous antibiotics

     Emergent surgical exploration and debridement with broad-spectrum intravenous antibiotics is most appropriate, because pain out of proportion, crepitus, bullae, and rapid systemic toxicity indicate necrotizing fasciitis, a surgical emergency in which early operative source control is the most important determinant of survival. Outpatient oral antibiotics, topical therapy, and antifungal observation all fatally delay the debridement this infection demands.

515. A previously healthy 32-year-old returns from a cruise with 24 hours of sudden vomiting, watery nonbloody diarrhea, and cramps; several fellow passengers are similarly ill. She is mildly dehydrated but hemodynamically stable. Which management is most appropriate for this likely viral gastroenteritis?
     • Empiric intravenous ceftriaxone
     • Immediate stool transplant
     • Oral antifungal therapy
     • Oral rehydration and supportive care without routine antibiotics

     Correct answer: Oral rehydration and supportive care without routine antibiotics

     Oral rehydration and supportive care without routine antibiotics is most appropriate, because an acute outbreak of vomiting and watery nonbloody diarrhea on a cruise is characteristic of a self-limited viral gastroenteritis such as norovirus, for which fluid and electrolyte replacement is the mainstay. Empiric antibiotics, stool transplantation, and antifungal therapy do not address a self-limited viral enteric infection and are not indicated.

516. A 19-year-old presents with several days of fatigue, sore throat, fever, and tender posterior cervical lymphadenopathy. Examination shows exudative tonsillitis and splenomegaly, and a heterophile antibody test is positive. He plays on the rugby team. Which counseling point is most important?
     • Start amoxicillin to shorten the course
     • Avoid contact sports for several weeks because of the risk of splenic rupture
     • Routine corticosteroids are indicated for all patients
     • Expect full resolution within 48 hours

     Correct answer: Avoid contact sports for several weeks because of the risk of splenic rupture

     Avoiding contact sports for several weeks because of the risk of splenic rupture is the most important counseling point, because infectious mononucleosis from Epstein-Barr virus causes splenomegaly that can rupture with abdominal trauma. Amoxicillin frequently triggers a rash and does not treat the virus, routine corticosteroids are reserved for complications such as airway compromise, and mononucleosis fatigue often persists for weeks rather than resolving in two days.

517. A 26-year-old man develops a high fever, severe headache, retro-orbital pain, diffuse myalgias described as breakbone pain, and a maculopapular rash four days after returning from Southeast Asia. Laboratory studies show leukopenia and thrombocytopenia. Which mosquito-borne infection is most likely?
     • Dengue fever
     • Lyme disease
     • Influenza
     • Rocky Mountain spotted fever

     Correct answer: Dengue fever

     Dengue fever is most likely, because high fever, retro-orbital pain, severe myalgias described as breakbone pain, rash, leukopenia, and thrombocytopenia in a traveler returning from an endemic tropical region are characteristic of this mosquito-borne flavivirus. Lyme disease is tick-borne with erythema migrans, influenza lacks retro-orbital pain and the travel link, and Rocky Mountain spotted fever follows tick exposure in endemic regions of the Americas.

518. A 40-year-old hiker in North Carolina presents with several days of fever, severe headache, and myalgias, followed by a maculopapular rash that began on the wrists and ankles and spread centrally, including the palms and soles. He removed a tick a week ago. Which treatment should be started without waiting for confirmatory testing?
     • Oral amoxicillin
     • Doxycycline
     • Intravenous vancomycin
     • Oral fluconazole

     Correct answer: Doxycycline

     Doxycycline should be started empirically without waiting for confirmation, because fever, headache, and a rash that begins on the wrists and ankles and spreads to the palms and soles after a tick bite is classic for Rocky Mountain spotted fever, where early doxycycline reduces mortality. Amoxicillin and vancomycin do not treat the rickettsial organism, and fluconazole is an antifungal with no role in this tick-borne infection.

519. A 7-year-old presents with a paroxysmal cough occurring in severe fits, sometimes followed by an inspiratory whooping sound and post-tussive vomiting, persisting for three weeks after an initial mild upper respiratory phase. He is incompletely vaccinated. Which infection is most likely, and which antibiotic class is preferred?
     • Respiratory syncytial virus, treated with ribavirin
     • Pertussis (whooping cough), treated with a macrolide such as azithromycin
     • Streptococcal pharyngitis, treated with penicillin
     • Influenza, treated with oseltamivir

     Correct answer: Pertussis (whooping cough), treated with a macrolide such as azithromycin

     Pertussis, or whooping cough, treated with a macrolide such as azithromycin is most likely, because a prolonged paroxysmal cough with inspiratory whoop and post-tussive emesis after a catarrhal phase in an incompletely vaccinated child is characteristic of Bordetella pertussis, for which macrolides are first-line. Respiratory syncytial virus causes bronchiolitis in infants, streptococcal pharyngitis causes sore throat rather than a whooping cough, and influenza is an acute febrile illness without this prolonged paroxysmal pattern.

520. A 38-year-old man has thick, well-demarcated plaques with adherent silvery scale over the extensor elbows and knees, plus persistent flaking and itching of the scalp at the hairline. He recently started a new medication for hypertension and his plaques worsened. Which commonly prescribed drug class is most likely to have exacerbated his psoriasis?
     • Calcium channel blockers
     • Beta blockers
     • Thiazide diuretics
     • Angiotensin receptor blockers

     Correct answer: Beta blockers

     Beta blockers are the antihypertensive class most strongly linked to triggering or worsening psoriasis, and stopping the offending agent or switching classes often improves the plaques. Calcium channel blockers, thiazide diuretics, and angiotensin receptor blockers are not classic psoriasis aggravators, so recognizing the beta blocker as the likely culprit allows the clinician to address a reversible exacerbating factor rather than escalating topical therapy unnecessarily.

521. A 50-year-old woman with extensive plaque psoriasis covering more than 15 percent of her body surface has failed topical therapy and phototherapy. Her clinician plans a systemic agent that requires monitoring of complete blood count and liver function and avoidance of alcohol. Which systemic therapy is being described?
     • Topical calcipotriene
     • Narrowband ultraviolet B light
     • Methotrexate
     • Oral antihistamine

     Correct answer: Methotrexate

     Methotrexate is the systemic agent that requires periodic complete blood count and liver function monitoring and counseling to avoid alcohol because of additive hepatotoxicity, making it appropriate for extensive disease that has failed topical and light therapy. Topical calcipotriene and narrowband ultraviolet B are the prior steps that already failed, and an oral antihistamine only addresses itch, so methotrexate best fits the monitoring profile and severity described.

522. A 60-year-old man with a long history of plaque psoriasis presents with rapidly spreading erythema involving nearly his entire body surface, with diffuse scaling, shivering, and tachycardia after abruptly stopping oral corticosteroids. Why does this erythrodermic flare warrant urgent evaluation?
     • It commonly resolves without any intervention within hours
     • It impairs thermoregulation and fluid balance and can lead to high-output cardiac failure
     • It indicates the psoriasis has become contagious
     • It signals transformation of psoriasis into melanoma

     Correct answer: It impairs thermoregulation and fluid balance and can lead to high-output cardiac failure

     Erythrodermic psoriasis is urgent because diffuse skin involvement disrupts the skin barrier, impairing thermoregulation and causing large fluid, electrolyte, and protein losses, with peripheral vasodilation that can precipitate high-output cardiac failure. It does not resolve spontaneously within hours, psoriasis is not contagious, and it does not transform into melanoma, so the systemic physiologic consequences are what make hospitalization and supportive care necessary, and abrupt steroid withdrawal is a recognized trigger.

523. A 45-year-old woman has shiny, sharply demarcated, nonscaly erythematous plaques located in the inframammary folds, axillae, and gluteal cleft. The plaques lack the thick silvery scale seen elsewhere because of the moist environment. Which variant of psoriasis does this describe?
     • Guttate psoriasis
     • Pustular psoriasis
     • Inverse psoriasis
     • Erythrodermic psoriasis

     Correct answer: Inverse psoriasis

     Inverse psoriasis affects the intertriginous skin folds such as the axillae, inframammary creases, and gluteal cleft, where moisture and friction produce smooth, shiny, sharply marginated red plaques that lack the characteristic thick scale. Guttate psoriasis produces small drop-like papules on the trunk, pustular psoriasis features sterile pustules, and erythrodermic psoriasis is near-total body erythema, so the flexural, nonscaly presentation is specific to the inverse pattern.

524. A 32-year-old man is being treated for moderate-to-severe plaque psoriasis with a biologic agent that blocks the interleukin-17 pathway. Before starting and during therapy, which screening is most important given the immunosuppressive nature of the drug?
     • Routine bone density scanning
     • Baseline and serial echocardiograms
     • Annual colonoscopy
     • Screening for latent tuberculosis

     Correct answer: Screening for latent tuberculosis

     Screening for latent tuberculosis is most important before and during biologic therapy for psoriasis because agents that suppress key inflammatory pathways increase the risk of reactivating latent infection. Bone density scanning, echocardiograms, and colonoscopy are not standard pre-biologic requirements for psoriasis, so tuberculosis screening is the critical safety step that allows treatment of latent infection before immunosuppression begins.

525. A 70-year-old man with extensive sun damage develops a melanoma under his thumbnail that presents as a pigmented longitudinal band widening over months with extension of pigment onto the surrounding nail fold. Which sign supports a diagnosis of subungual melanoma in this pigmented nail streak?
     • Pigment extending onto the adjacent proximal nail fold (Hutchinson sign)
     • Symmetric uniform thin brown band stable for years
     • Complete absence of any pigment
     • Pinpoint bleeding when scale is removed

     Correct answer: Pigment extending onto the adjacent proximal nail fold (Hutchinson sign)

     The Hutchinson sign, periungual extension of pigment from a nail band onto the adjacent proximal or lateral nail fold, supports subungual melanoma and warrants biopsy. A symmetric thin band stable for years is reassuring and benign, absence of pigment would not describe a pigmented streak, and pinpoint bleeding under scale is the Auspitz sign of psoriasis, so pigment spreading to the nail fold is the worrisome feature pointing to melanoma.

526. A 65-year-old woman has multiple rough, scaly, sandpaper-like erythematous macules on her balding scalp and forearms after decades of sun exposure. One lesion has become thicker and tender. These lesions are best understood as which type of process?
     • Benign seborrheic keratoses with no malignant potential
     • Viral warts requiring antiviral therapy
     • Premalignant actinic keratoses that can progress to squamous cell carcinoma
     • Contact dermatitis from a topical product

     Correct answer: Premalignant actinic keratoses that can progress to squamous cell carcinoma

     Actinic keratoses are premalignant, sun-induced rough scaly macules that carry a risk of progressing to squamous cell carcinoma, and a lesion that becomes thickened, indurated, or tender raises concern for that transformation and may warrant biopsy. Seborrheic keratoses are benign stuck-on lesions with no malignant potential, warts are virally induced papillomatous growths, and contact dermatitis is an itchy inflammatory eruption, so the sun-related premalignant nature of actinic keratoses is the key concept.

527. A 58-year-old man presents with a waxy, well-circumscribed, light-brown to black papule on his back that appears stuck onto the skin surface with a verrucous texture and visible keratin-filled pits. It is asymptomatic and has been slowly present for years. Which lesion is most consistent with this benign growth?
     • Melanoma
     • Basal cell carcinoma
     • Actinic keratosis
     • Seborrheic keratosis

     Correct answer: Seborrheic keratosis

     A seborrheic keratosis is most consistent with a waxy, stuck-on appearing papule that has a verrucous surface and keratin-filled pseudocysts, and these benign lesions are extremely common in older adults. Melanoma shows asymmetry, border irregularity, and recent change, basal cell carcinoma is a pearly telangiectatic papule, and actinic keratosis is a rough scaly premalignant macule, so the stuck-on waxy quality identifies the benign seborrheic keratosis.

528. A clinician evaluating a patient with darker skin is taught that melanoma can present differently than in lighter-skinned patients. In which anatomic distribution does acral lentiginous melanoma, the subtype more commonly diagnosed in people with darker skin, most characteristically arise?
     • Sun-exposed face and forearms
     • Palms, soles, and beneath the nails
     • The scalp under the hairline only
     • The eyelid margins exclusively

     Correct answer: Palms, soles, and beneath the nails

     Acral lentiginous melanoma characteristically arises on the palms, soles, and subungual regions, and it is the subtype disproportionately diagnosed in patients with darker skin, where melanoma is more often found in these non-sun-exposed sites. The sun-exposed face and forearms are typical of lentigo maligna melanoma, and the scalp or eyelid margins are not the defining acral locations, so recognizing palmar, plantar, and subungual sites improves detection in skin of color.

529. A 72-year-old woman has a recurrent basal cell carcinoma on the medial canthus of the eye, an anatomically sensitive area with a high recurrence risk. Which treatment offers the highest cure rate with maximal tissue sparing for this lesion?
     • Simple shave biopsy without margins
     • Topical antibiotic ointment
     • Mohs micrographic surgery
     • Watchful waiting with annual photographs

     Correct answer: Mohs micrographic surgery

     Mohs micrographic surgery offers the highest cure rate while sparing the maximum amount of normal tissue, making it the preferred treatment for basal cell carcinoma in cosmetically and functionally critical sites such as the medial canthus, and for recurrent tumors. A shave without margin control leaves residual tumor, a topical antibiotic does not treat malignancy, and watchful waiting allows continued invasion, so Mohs surgery best balances cure and tissue preservation here.

530. A 19-year-old woman with severe nodulocystic acne is started on oral isotretinoin. Two months in, she reports very dry, chapped lips and dry eyes but no other complaints. Which counseling point correctly addresses this common adverse effect?
     • These symptoms mean the drug must be stopped immediately
     • She should double the dose to overcome the dryness
     • Dryness indicates a serious allergic reaction
     • Cheilitis and mucocutaneous dryness are expected and managed with lip balm and lubricating eye drops

     Correct answer: Cheilitis and mucocutaneous dryness are expected and managed with lip balm and lubricating eye drops

     Cheilitis and mucocutaneous dryness affecting the lips and eyes are among the most common and expected side effects of isotretinoin, and they are managed supportively with frequent lip balm and lubricating eye drops rather than discontinuation. Stopping abruptly is unnecessary for routine dryness, doubling the dose worsens the effect, and dryness is not an allergic reaction, so reassurance and symptomatic care are the appropriate response.

531. A 26-year-old woman has central facial redness with flushing, persistent erythema of the cheeks and nose, telangiectasias, and occasional papules and pustules, but no comedones. Flares are triggered by sun, spicy food, and alcohol. Which diagnosis best fits this presentation?
     • Acne vulgaris
     • Rosacea
     • Seborrheic dermatitis
     • Systemic lupus erythematosus malar rash

     Correct answer: Rosacea

     Rosacea best fits centrofacial flushing, persistent erythema, telangiectasias, and inflammatory papules and pustules without comedones, typically triggered by sun, heat, spicy food, and alcohol in middle-aged adults. Acne vulgaris characteristically includes comedones, seborrheic dermatitis produces greasy scale in the nasolabial folds and scalp, and the lupus malar rash spares the nasolabial folds and lacks pustules, so the comedone-free, trigger-related facial erythema identifies rosacea.

532. A 40-year-old man with rosacea has prominent papules and pustules on the cheeks. He has no ocular symptoms and the disease is moderate. Which topical agent is an appropriate first-line treatment for the papulopustular component of rosacea?
     • Topical high-potency corticosteroid
     • Topical metronidazole
     • Topical benzoyl peroxide alone for comedones
     • Topical antifungal cream

     Correct answer: Topical metronidazole

     Topical metronidazole is an established first-line treatment for the papulopustular component of rosacea and reduces inflammatory lesions with a favorable safety profile. High-potency topical corticosteroids can worsen rosacea and cause steroid-induced dermatitis, comedones are not a feature of rosacea so benzoyl peroxide for comedones is misdirected, and antifungal cream targets dermatophytes, so metronidazole is the appropriate evidence-based choice.

533. A 5-year-old child has intensely itchy eczematous patches, and the parent asks why scratching seems to make the rash spread and persist. Which concept best explains the chronicity and lichenification seen in atopic dermatitis?
     • Direct bacterial spread from scratching one site to another
     • The itch-scratch cycle, in which scratching damages the barrier and provokes more inflammation and itch
     • An autoimmune attack on hair follicles
     • Allergy to all topical moisturizers

     Correct answer: The itch-scratch cycle, in which scratching damages the barrier and provokes more inflammation and itch

     The itch-scratch cycle explains the chronicity of atopic dermatitis because scratching further damages an already impaired skin barrier, releasing inflammatory mediators that intensify itching and lead to thickened, lichenified skin over time. The pattern is not primarily bacterial spread, atopic dermatitis is not a follicular autoimmune process, and patients are not universally allergic to moisturizers, so interrupting the itch-scratch cycle with emollients and anti-inflammatory therapy is central to control.

534. A 4-year-old with atopic dermatitis develops a sudden eruption of monomorphic punched-out erosions and vesicles with fever, spreading over the eczematous areas. This represents eczema herpeticum. Which intervention is most urgent?
     • A higher-potency topical steroid only
     • Reassurance that it will resolve with emollients
     • Prompt systemic acyclovir for disseminated herpes simplex infection
     • Oral antihistamine alone

     Correct answer: Prompt systemic acyclovir for disseminated herpes simplex infection

     Eczema herpeticum is a potentially serious disseminated herpes simplex virus infection of eczematous skin, and prompt systemic acyclovir is the most urgent intervention to prevent complications such as widespread infection and ocular involvement. A higher-potency topical steroid can worsen viral spread, emollients alone do not treat the infection, and an antihistamine addresses only itch, so antiviral therapy is the critical step when monomorphic punched-out vesicles appear on atopic skin.

535. A homemaker presents with itchy, scaly, erythematous patches confined to the dorsal hands with fissuring, worse after frequent handwashing and exposure to cleaning agents, and there is no personal history of atopy. Which type of dermatitis is most likely?
     • Atopic dermatitis
     • Psoriasis
     • Tinea manuum
     • Irritant contact dermatitis

     Correct answer: Irritant contact dermatitis

     Irritant contact dermatitis is most likely because repeated exposure to water, soaps, and cleaning chemicals directly damages the skin barrier of the hands, producing itchy, scaly, fissured patches without requiring prior sensitization or a personal atopic history. Atopic dermatitis typically involves flexural sites with an atopic background, psoriasis shows well-demarcated silvery plaques, and tinea manuum is usually unilateral with a KOH-positive scaling border, so the occupational irritant exposure points to irritant contact dermatitis.

536. A 30-year-old develops an intensely itchy, linear, vesicular eruption in streaks on the forearms two days after hiking through brush. Which mechanism underlies this allergic contact dermatitis from poison ivy?
     • An IgE-mediated immediate hypersensitivity reaction
     • A delayed type IV cell-mediated hypersensitivity reaction to urushiol
     • Direct toxic injury without immune involvement
     • An autoimmune blistering reaction against desmoglein

     Correct answer: A delayed type IV cell-mediated hypersensitivity reaction to urushiol

     Allergic contact dermatitis from poison ivy is a delayed type IV cell-mediated hypersensitivity reaction to the plant antigen urushiol, which is why the linear vesicular eruption appears a day or more after exposure along areas of plant contact. It is not IgE-mediated immediate hypersensitivity, not simple toxic injury, and not an autoimmune blistering process against desmoglein, so understanding the delayed cell-mediated mechanism explains the timing and distribution of the rash.

537. An infant has thick, greasy, yellow scale adherent to the scalp, commonly called cradle cap, with mild erythema and no significant itching. Which condition does this represent, and what is appropriate initial management?
     • Tinea capitis requiring oral antifungals
     • Atopic dermatitis requiring systemic steroids
     • Seborrheic dermatitis managed with gentle emollients and antifungal or low-potency measures
     • Impetigo requiring oral antibiotics

     Correct answer: Seborrheic dermatitis managed with gentle emollients and antifungal or low-potency measures

     Greasy yellow scale on an infant scalp represents seborrheic dermatitis, or cradle cap, which is benign and managed with gentle emollients to loosen scale and, when needed, mild antifungal shampoos or low-potency topical measures, often resolving on its own. Tinea capitis causes scaly hair loss with broken hairs, atopic dermatitis is intensely itchy and does not need systemic steroids first, and impetigo shows honey-colored crusts, so conservative care for seborrheic dermatitis is appropriate.

538. A 25-year-old presents with sudden onset of transient, intensely itchy, raised pink wheals over the trunk and arms that individually fade within 24 hours and migrate to new sites, with no scarring. Which condition does this describe?
     • Erythema migrans
     • Plaque psoriasis
     • Stasis dermatitis
     • Urticaria (hives)

     Correct answer: Urticaria (hives)

     Urticaria, or hives, is characterized by transient, intensely pruritic, raised wheals that individually resolve within about 24 hours and migrate to new locations without leaving residual marks, reflecting transient dermal edema from mast cell histamine release. Erythema migrans is a slowly expanding annular Lyme lesion, plaque psoriasis produces fixed scaly plaques, and stasis dermatitis causes chronic lower-leg changes, so the fleeting, migratory wheals identify urticaria.

539. A 35-year-old man has a single oval, salmon-colored patch with a fine collarette of scale on his trunk, followed a week later by numerous smaller oval scaly patches aligned along skin cleavage lines in a Christmas-tree pattern on the back. The eruption is mildly itchy and self-limited. Which diagnosis is most likely?
     • Secondary syphilis
     • Tinea versicolor
     • Pityriasis rosea
     • Guttate psoriasis

     Correct answer: Pityriasis rosea

     Pityriasis rosea is most likely given the initial herald patch with a trailing collarette of scale followed by a secondary eruption of oval lesions oriented along skin tension lines in a Christmas-tree distribution, typically self-limited over weeks. Secondary syphilis classically involves the palms and soles and warrants serologic testing, tinea versicolor causes hypopigmented or hyperpigmented macules with a positive KOH, and guttate psoriasis produces small drop-shaped plaques, so the herald patch and cleavage-line pattern point to pityriasis rosea.

540. A 28-year-old develops well-demarcated hypopigmented and slightly tan macules with very fine scale on the upper chest and back that become more noticeable after sun exposure. A KOH preparation shows short hyphae and round yeast forms in a spaghetti-and-meatballs pattern. Which infection is this and what is appropriate therapy?
     • Tinea versicolor treated with topical selenium sulfide or an azole antifungal
     • Vitiligo treated with phototherapy
     • Impetigo treated with topical mupirocin
     • Erythrasma treated with oral acyclovir

     Correct answer: Tinea versicolor treated with topical selenium sulfide or an azole antifungal

     Tinea versicolor, caused by Malassezia yeast, produces fine-scaling hypopigmented or tan macules on the trunk that are accentuated after sun exposure, and the KOH spaghetti-and-meatballs appearance confirms it; treatment is topical selenium sulfide or an azole antifungal. Vitiligo shows depigmented patches without scale or yeast, impetigo causes honey-colored crusts, and erythrasma is a corynebacterial intertriginous infection, so the Malassezia findings identify tinea versicolor and its antifungal management.

541. A patient with diabetes has macerated, itchy skin in the toe web spaces with peeling and a moist scaling that extends along the soles in a moccasin distribution. KOH confirms dermatophyte hyphae. Beyond antifungal therapy, why is good foot care emphasized in this patient?
     • Tinea pedis is purely cosmetic and needs no further attention
     • Fissures from tinea pedis can serve as a portal for bacterial cellulitis, especially in diabetes
     • It indicates the antifungal will not work
     • Foot care prevents the fungus from becoming a virus

     Correct answer: Fissures from tinea pedis can serve as a portal for bacterial cellulitis, especially in diabetes

     Good foot care matters in tinea pedis because macerated, fissured interdigital skin can serve as a portal of entry for bacteria, predisposing to cellulitis, a risk that is heightened in people with diabetes who have impaired healing and sensation. Tinea pedis is not merely cosmetic, the presence of fissures does not mean antifungals fail, and fungi do not convert into viruses, so emphasizing skin integrity reduces the risk of secondary bacterial infection.

542. A 60-year-old presents with a unilateral, painful vesicular eruption grouped on an erythematous base that follows a single thoracic dermatome and does not cross the midline, preceded by several days of burning pain. Which condition is this and what is the most appropriate treatment?
     • Contact dermatitis treated with topical steroids
     • Bullous pemphigoid treated with systemic steroids
     • Herpes zoster treated with oral antivirals such as valacyclovir
     • Tinea corporis treated with topical antifungals

     Correct answer: Herpes zoster treated with oral antivirals such as valacyclovir

     Herpes zoster is identified by a painful, grouped vesicular eruption confined to one dermatome that respects the midline and is preceded by prodromal pain, reflecting reactivation of latent varicella-zoster virus, and prompt oral antivirals such as valacyclovir reduce duration and the risk of postherpetic neuralgia. Contact dermatitis is not dermatomal, bullous pemphigoid causes tense bullae over wider areas, and tinea corporis is an annular fungal plaque, so the dermatomal vesicles indicate shingles.

543. A 7-year-old has honey-colored crusted erosions around the nose and mouth that began as small vesicles and pustules and are spreading. There is no systemic illness. Which superficial bacterial skin infection does this represent?
     • Erysipelas
     • Impetigo
     • Necrotizing fasciitis
     • Folliculitis

     Correct answer: Impetigo

     Impetigo is a superficial bacterial skin infection, typically from Staphylococcus aureus or Streptococcus pyogenes, that presents with vesicles and pustules evolving into characteristic honey-colored crusts around the nose and mouth in children, and it is highly contagious but usually without systemic illness. Erysipelas is a sharply demarcated dermal cellulitis with fever, necrotizing fasciitis is a deep limb-threatening infection with severe pain, and folliculitis centers on hair follicles, so the honey-colored crusts identify impetigo.

544. A patient reports intense generalized itching that is worse at night, and examination reveals thin, serpiginous burrows in the finger webs and flexor wrists, with similar itching reported by household members. Which diagnosis is most likely and how is it confirmed?
     • Atopic dermatitis, confirmed by patch testing
     • Psoriasis, confirmed by the Auspitz sign
     • Scabies, confirmed by skin scraping showing mites, eggs, or feces
     • Contact dermatitis, confirmed by a Tzanck smear

     Correct answer: Scabies, confirmed by skin scraping showing mites, eggs, or feces

     Scabies is most likely given intense nocturnal itching, thin serpiginous burrows in the finger webs and wrists, and itching in close contacts, and it is confirmed by skin scraping that reveals the mite, eggs, or fecal pellets under the microscope. Patch testing evaluates contact allergy, the Auspitz sign relates to psoriasis, and a Tzanck smear detects viral infections, so the burrows, nocturnal itch, and household spread, confirmed by scraping, point to scabies.

545. An 80-year-old develops large, tense, fluid-filled bullae on the trunk and flexural areas with surrounding urticarial plaques; the blisters do not rupture easily and the Nikolsky sign is negative. Which autoimmune blistering disorder does this describe?
     • Pemphigus vulgaris
     • Bullous pemphigoid
     • Dermatitis herpetiformis
     • Impetigo

     Correct answer: Bullous pemphigoid

     Bullous pemphigoid is described by large, tense, durable subepidermal bullae on the trunk and flexural skin of an elderly patient, often with urticarial plaques and a negative Nikolsky sign because the split is deep at the dermoepidermal junction. Pemphigus vulgaris produces flaccid, easily ruptured blisters with a positive Nikolsky sign, dermatitis herpetiformis is intensely itchy grouped papulovesicles, and impetigo is superficial with honey crusts, so the tense bullae with negative Nikolsky identify bullous pemphigoid.

546. A 22-year-old develops acute symmetric targetoid lesions with a central dusky zone, a surrounding pale ring, and an outer red ring on the palms and extremities about one week after a herpes simplex outbreak. Which condition does this classic target morphology indicate?
     • Urticaria
     • Tinea corporis
     • Erythema multiforme
     • Psoriasis

     Correct answer: Erythema multiforme

     Erythema multiforme is indicated by symmetric targetoid lesions with three zones, a central dusky or blistered area, a pale edematous ring, and an outer erythematous ring, classically on the palms and extremities and frequently triggered by a preceding herpes simplex virus infection. Urticaria produces transient wheals without fixed three-zone targets, tinea corporis is a single annular scaling plaque, and psoriasis shows silvery plaques, so the true target lesions following herpes identify erythema multiforme.

547. A 24-year-old woman has recurrent painful, deep-seated inflammatory nodules, draining sinus tracts, and scarring localized to the axillae and groin, worsening over years and flaring around her menses. Which chronic follicular skin disorder is most consistent with this presentation?
     • Hidradenitis suppurativa
     • Simple furunculosis from poor hygiene
     • Cutaneous tuberculosis
     • Contact dermatitis to deodorant

     Correct answer: Hidradenitis suppurativa

     Hidradenitis suppurativa is most consistent with recurrent, painful, deep inflammatory nodules, draining sinus tracts, and scarring in the apocrine-bearing intertriginous areas such as the axillae and groin, often with a chronic relapsing course and hormonal flares. It is a disorder of follicular occlusion rather than poor hygiene, cutaneous tuberculosis is rare and not folliculocentric in this pattern, and deodorant contact dermatitis causes itchy eczematous patches rather than draining sinus tracts, so the recurrent intertriginous nodules and tracts identify hidradenitis suppurativa.