- A 28-year-old woman has had three episodes over the past year of painless, non-itchy swelling of her hands, face, and on one occasion her bowel wall, causing severe abdominal pain. Episodes do not respond to antihistamines or corticosteroids, and she has a family history of similar attacks. Which laboratory finding would best confirm the suspected diagnosis?
- Elevated serum tryptase during an attack
- Low C4 level with reduced C1 esterase inhibitor function
- Elevated total IgE with positive aeroallergen skin tests
- Markedly elevated peripheral eosinophil count
Correct answer: Low C4 level with reduced C1 esterase inhibitor function
A low C4 level with reduced C1 esterase inhibitor function best confirms hereditary angioedema, the suspected diagnosis given recurrent non-pruritic angioedema unresponsive to antihistamines and steroids with a family history. C4 is consumed and stays low because the missing or dysfunctional C1 inhibitor fails to regulate the complement and contact pathways. Elevated tryptase indicates mast cell activation seen in anaphylaxis rather than bradykinin-mediated swelling, an elevated IgE with positive skin tests points to allergic atopy, and a high eosinophil count is nonspecific and not characteristic of this condition.
- A patient with confirmed hereditary angioedema presents to the emergency department with rapidly progressing tongue and throat swelling and a change in voice. After securing the airway as needed, which therapy directly targets the underlying mechanism of this acute attack?
- High-dose intravenous methylprednisolone
- Intramuscular epinephrine and intravenous diphenhydramine
- A bradykinin B2 receptor antagonist or C1 inhibitor concentrate
- Inhaled racemic epinephrine alone
Correct answer: A bradykinin B2 receptor antagonist or C1 inhibitor concentrate
A bradykinin B2 receptor antagonist or C1 inhibitor concentrate is correct because hereditary angioedema attacks are driven by excess bradykinin, so replacing C1 inhibitor or blocking the bradykinin B2 receptor addresses the actual mediator. These agents are the targeted acute treatments for laryngeal involvement. Corticosteroids and antihistamines treat histamine-mediated allergic angioedema and are ineffective here, epinephrine and diphenhydramine likewise target the allergic pathway rather than bradykinin, and racemic epinephrine alone does not reverse a bradykinin-mediated attack.
- A 45-year-old man develops flushing, hives, abdominal cramping, and near-syncope only when vigorous exercise follows a meal containing wheat, although he tolerates either wheat or exercise alone without symptoms. Which diagnosis best explains this pattern?
- Food-dependent exercise-induced anaphylaxis
- Exercise-induced bronchospasm
- Scombroid poisoning
- Vasovagal syncope triggered by exertion
Correct answer: Food-dependent exercise-induced anaphylaxis
Food-dependent exercise-induced anaphylaxis best explains symptoms that appear only when a specific food and exercise are combined, with tolerance of each in isolation. The cofactor of exercise lowers the threshold for an IgE-mediated reaction to the ingested allergen, commonly wheat. Exercise-induced bronchospasm produces wheezing and dyspnea but not urticaria and abdominal cramping, scombroid poisoning follows eating spoiled fish regardless of exertion, and vasovagal syncope does not cause hives or the food-plus-exercise dependency described here.
- A 22-year-old man with a known severe peanut allergy accidentally ingests a contaminated cookie and is treated promptly with intramuscular epinephrine, with good initial response. To reduce the risk of a recurrent reaction in the hours after treatment, what is the most appropriate disposition?
- Immediate discharge once urticaria fades, with no further observation
- Admission for several days of intravenous corticosteroids
- Discharge with instructions to take diphenhydramine every six hours for one week
- A period of monitored observation before discharge to watch for a biphasic reaction
Correct answer: A period of monitored observation before discharge to watch for a biphasic reaction
A period of monitored observation before discharge is most appropriate because anaphylaxis can recur as a biphasic reaction hours after the initial symptoms resolve, so patients are watched after epinephrine treatment to detect and re-treat any return of symptoms. Immediate discharge once hives fade risks missing a late deterioration, multi-day intravenous corticosteroids are not required for an uncomplicated reaction that responded to epinephrine, and scheduled diphenhydramine does not prevent recurrent anaphylaxis and may falsely reassure the patient.
- Six hours after receiving a first dose of intravenous trimethoprim-sulfamethoxazole, a patient develops widespread blistering of the skin, painful erosions of the lips and oral mucosa, and detachment of the epidermis affecting less than 10 percent of the body surface. Which immune mechanism underlies this severe reaction?
- IgE-mediated mast cell degranulation
- Immune-complex deposition with complement activation
- IgG antibody-mediated platelet destruction
- Cytotoxic T-cell-mediated keratinocyte apoptosis (a type IV reaction)
Correct answer: Cytotoxic T-cell-mediated keratinocyte apoptosis (a type IV reaction)
Cytotoxic T-cell-mediated keratinocyte apoptosis, a type IV reaction, underlies this severe blistering mucocutaneous drug reaction in which activated T cells and their effectors trigger widespread epidermal cell death with mucosal involvement. The delayed onset and full-thickness skin damage are characteristic of this T-cell-driven mechanism. IgE-mediated mast cell degranulation causes immediate urticaria and anaphylaxis, immune-complex deposition produces serum sickness or vasculitis, and IgG-mediated platelet destruction describes immune thrombocytopenia rather than a blistering skin reaction.
- A patient labeled as allergic to amoxicillin (childhood rash) now needs a cephalosporin for a serious infection. Current understanding of beta-lactam cross-reactivity should lead the clinician to conclude which of the following?
- Cross-reactivity between penicillins and most cephalosporins is low and largely depends on similarity of the side chains rather than the shared beta-lactam ring
- All cephalosporins are absolutely contraindicated in anyone with any penicillin allergy history
- Cephalosporins and penicillins never cross-react under any circumstance
- Cross-reactivity is determined solely by the shared beta-lactam ring, so all beta-lactams must be avoided
Correct answer: Cross-reactivity between penicillins and most cephalosporins is low and largely depends on similarity of the side chains rather than the shared beta-lactam ring
The clinician should conclude that cross-reactivity between penicillins and most cephalosporins is low and depends largely on side-chain similarity rather than the shared beta-lactam ring. Cephalosporins with dissimilar side chains can usually be given safely even to many penicillin-allergic patients. Declaring all cephalosporins absolutely contraindicated overstates the risk and denies effective therapy, claiming they never cross-react ignores documented side-chain-related reactions, and attributing cross-reactivity solely to the shared ring is outdated and would inappropriately bar all beta-lactams.
- A 50-year-old woman reports that within minutes of receiving intravenous iodinated contrast during a CT scan she developed flushing, urticaria, and wheezing. Regarding the immune basis of this immediate contrast reaction, which statement is most accurate?
- It is always a true IgE-mediated allergy requiring lifelong avoidance of all iodine-containing foods
- It may occur through direct mast cell activation and is not reliably predicted by iodine or shellfish allergy
- It reflects a type IV delayed hypersensitivity that develops over several days
- It is caused by immune-complex deposition and is treated with plasmapheresis
Correct answer: It may occur through direct mast cell activation and is not reliably predicted by iodine or shellfish allergy
The most accurate statement is that an immediate contrast reaction may occur through direct mast cell activation and is not reliably predicted by iodine or shellfish allergy. Many such reactions are non-IgE-mediated, and the long-standing belief that shellfish or dietary iodine allergy predicts contrast reactions has been discredited. Labeling every reaction a true IgE allergy requiring avoidance of dietary iodine is incorrect, the rapid onset is inconsistent with a delayed type IV reaction, and immune-complex deposition treated with plasmapheresis does not describe an acute contrast reaction.
- A patient with a documented severe IgE-mediated allergy to a specific chemotherapy agent has no equally effective alternative for treating an aggressive cancer. Which strategy allows the medication to be administered while minimizing the risk of an immediate reaction?
- A single full therapeutic dose given after premedication with antihistamines only
- Rapid drug desensitization using gradually escalating doses under close monitoring
- Permanent substitution with a less effective unrelated agent
- Administering the standard dose more slowly without changing the amount of each step
Correct answer: Rapid drug desensitization using gradually escalating doses under close monitoring
Rapid drug desensitization using gradually escalating doses under close monitoring is the strategy that allows administration of a needed drug despite an IgE-mediated allergy when no good alternative exists. Incremental dosing induces a temporary state of tolerance so the full dose can ultimately be delivered safely. A single full dose after antihistamines alone does not prevent a severe IgE-mediated reaction, permanent substitution with a less effective agent sacrifices necessary cancer therapy, and simply slowing a standard dose without dose escalation is not a recognized desensitization protocol.
- A 19-year-old woman is referred after two unexplained episodes of anaphylaxis, and during one episode she also had a recurrent itchy rash with reddish-brown skin macules that urticate when stroked. Her baseline serum tryptase is persistently elevated between episodes. Which underlying condition best accounts for this presentation?
- Hereditary angioedema
- Systemic mastocytosis
- Common variable immunodeficiency
- Chronic spontaneous urticaria
Correct answer: Systemic mastocytosis
Systemic mastocytosis best accounts for recurrent anaphylaxis together with reddish-brown skin lesions that urticate when stroked and a persistently elevated baseline tryptase. An abnormal accumulation of mast cells increases the baseline tryptase and predisposes to recurrent severe mediator-release reactions. Hereditary angioedema causes non-pruritic bradykinin-mediated swelling without elevated baseline tryptase, common variable immunodeficiency presents with recurrent infections and low immunoglobulins, and chronic spontaneous urticaria causes recurrent hives but not a persistently elevated baseline tryptase or anaphylaxis.
- A patient who carries an epinephrine auto-injector for a severe food allergy asks how the device should be used if a serious reaction occurs again. Which instruction is most appropriate?
- Inject into the lateral thigh at the first signs of a serious reaction and call emergency services
- Wait to see whether oral antihistamines control symptoms before using the injector
- Inject only into a vein for fastest effect
- Use the injector only after wheezing has clearly progressed to difficulty speaking
Correct answer: Inject into the lateral thigh at the first signs of a serious reaction and call emergency services
Injecting into the lateral thigh at the first signs of a serious reaction and calling emergency services is the most appropriate instruction because prompt intramuscular epinephrine into the outer thigh gives the fastest reliable absorption and early use improves outcomes in anaphylaxis. Waiting to see whether antihistamines work dangerously delays the only first-line therapy, intravenous self-injection is not how auto-injectors are designed to be used and risks harm, and withholding the device until symptoms become severe forfeits the benefit of early treatment.
- A 58-year-old man with chronic alcohol use is admitted after several days of poor intake. Over hours he develops confusion, horizontal gaze-evoked nystagmus, and a wide-based unsteady gait. Which immediate intervention is most appropriate before giving intravenous glucose?
- Administer parenteral thiamine
- Start high-dose intravenous corticosteroids
- Give a loading dose of an antiseizure medication
- Begin empiric broad-spectrum antibiotics
Correct answer: Administer parenteral thiamine
Administering parenteral thiamine is most appropriate because the triad of confusion, ophthalmoplegia with nystagmus, and gait ataxia in a malnourished person with alcohol use indicates Wernicke encephalopathy from thiamine deficiency, and thiamine must be given before or with glucose to avoid precipitating or worsening the deficiency. Early replacement can reverse the syndrome. Corticosteroids do not treat this nutritional disorder, an antiseizure medication does not address the underlying deficiency, and antibiotics are not indicated without evidence of infection.
- A 64-year-old man with metastatic prostate cancer reports several days of worsening mid-back pain followed today by leg weakness, numbness below the trunk, and difficulty urinating. On examination he has bilateral lower-extremity weakness with a sensory level. Which step is the most appropriate immediate priority?
- Outpatient physical therapy referral
- Urgent spinal magnetic resonance imaging and corticosteroids for suspected cord compression
- Reassurance with oral analgesics and follow-up in one month
- Lumbar puncture to measure opening pressure
Correct answer: Urgent spinal magnetic resonance imaging and corticosteroids for suspected cord compression
Urgent spinal magnetic resonance imaging together with corticosteroids is the most appropriate priority because back pain followed by bilateral leg weakness, a sensory level, and bladder dysfunction in a patient with metastatic cancer signals malignant spinal cord compression, a neurologic emergency in which prompt imaging and steroids preserve function. Delay risks irreversible paralysis. Physical therapy and routine analgesia with delayed follow-up dangerously postpone treatment, and lumbar puncture neither diagnoses nor treats compressive myelopathy.
- A 68-year-old woman is evaluated for a gradual decline over a year marked by a magnetic, shuffling gait, urinary incontinence, and mild cognitive slowing. Brain imaging shows enlarged ventricles out of proportion to cortical atrophy. Which diagnosis best fits this clinical triad?
- Alzheimer disease
- Parkinson disease
- Normal pressure hydrocephalus
- Vascular dementia from multiple cortical strokes
Correct answer: Normal pressure hydrocephalus
Normal pressure hydrocephalus best fits because the classic triad of a magnetic or shuffling gait disturbance, urinary incontinence, and cognitive decline with ventriculomegaly out of proportion to atrophy defines this potentially treatable cause of dementia and gait impairment. The gait disorder typically predominates and may improve with cerebrospinal fluid diversion. Alzheimer disease leads with memory loss without disproportionate ventricular enlargement, Parkinson disease features resting tremor and rigidity, and vascular dementia follows a stepwise course tied to discrete cortical infarcts.
- A 73-year-old man is brought in for cognitive decline featuring marked fluctuations in attention, recurrent well-formed visual hallucinations, and spontaneous parkinsonism. His family notes he acted out vivid dreams for years before the cognitive changes. Which dementia subtype does this presentation most strongly suggest?
- Frontotemporal dementia
- Alzheimer disease
- Creutzfeldt-Jakob disease
- Dementia with Lewy bodies
Correct answer: Dementia with Lewy bodies
Dementia with Lewy bodies is most strongly suggested because fluctuating cognition, recurrent detailed visual hallucinations, spontaneous parkinsonism, and a preceding history of dream-enactment behavior are core features of this synucleinopathy. Recognition matters in part because of marked sensitivity to antipsychotic medications. Frontotemporal dementia presents with early behavioral or language change rather than hallucinations, Alzheimer disease leads with amnestic decline, and Creutzfeldt-Jakob disease causes rapidly progressive dementia with myoclonus over weeks to months rather than this chronic fluctuating course.
- A 60-year-old man is brought in by his wife because over the past two years he has become disinhibited, socially inappropriate, and apathetic, with loss of empathy, while his memory and spatial skills remain relatively preserved. Imaging shows focal atrophy of the frontal and anterior temporal lobes. Which diagnosis best explains this pattern?
- Behavioral-variant frontotemporal dementia
- Alzheimer disease
- Normal pressure hydrocephalus
- Delirium from a urinary tract infection
Correct answer: Behavioral-variant frontotemporal dementia
Behavioral-variant frontotemporal dementia best explains this pattern because early, prominent personality and behavioral change with disinhibition, apathy, and loss of empathy, alongside relatively preserved memory and selective frontal and anterior temporal atrophy, characterizes this disorder, which often presents at a younger age than Alzheimer disease. The behavioral predominance is key. Alzheimer disease leads with memory loss, normal pressure hydrocephalus presents with gait, incontinence, and cognitive slowing, and delirium develops acutely with fluctuating attention and an identifiable trigger.
- A 55-year-old woman reports an uncomfortable, creeping urge to move her legs that appears in the evening when she is at rest, is relieved by walking, and disrupts her sleep. Her examination is normal. Which initial laboratory evaluation is most appropriate given a common reversible contributor to this disorder?
- Cerebrospinal fluid analysis
- Serum ferritin and iron studies
- Serum copper and ceruloplasmin
- Antinuclear antibody panel
Correct answer: Serum ferritin and iron studies
Checking serum ferritin and iron studies is most appropriate because the evening, rest-related urge to move the legs that is relieved by movement describes restless legs syndrome, and iron deficiency is a common, correctable contributor in which repletion can substantially improve symptoms. Identifying low iron stores directs treatment. Cerebrospinal fluid analysis is not part of the routine evaluation, copper and ceruloplasmin assess Wilson disease, and an antinuclear antibody panel screens for autoimmune disease unrelated to this sensorimotor sleep disorder.
- A 45-year-old man reports a bilateral hand tremor present when he holds a cup or writes but absent at rest, gradually worsening over years, with a similar tremor in his father. He notes the tremor temporarily improves after a glass of wine. Which diagnosis best explains this action tremor?
- Parkinson disease
- Cerebellar intention tremor from a stroke
- Essential tremor
- Drug-induced parkinsonism
Correct answer: Essential tremor
Essential tremor best explains this presentation because a bilateral postural and kinetic tremor that appears with action, worsens slowly over years, often runs in families, and transiently improves with alcohol is the hallmark of this common movement disorder. The action-induced, symmetric, hereditary pattern distinguishes it. Parkinson disease produces a resting tremor with bradykinesia and rigidity, a cerebellar intention tremor follows acute focal injury with other cerebellar signs, and drug-induced parkinsonism arises after dopamine-blocking medications rather than over many years with a family history.
- A 30-year-old man with epilepsy that has remained uncontrolled despite adequate trials of three appropriately chosen antiseizure medications continues to have disabling focal seizures. Which characterization of his condition and next step is most accurate?
- He simply needs higher doses of the same drugs indefinitely
- His seizures are certainly psychogenic and medication should be stopped
- No further evaluation is warranted because epilepsy cannot be treated beyond medications
- He has drug-resistant epilepsy and should be referred to an epilepsy center for evaluation including possible surgery
Correct answer: He has drug-resistant epilepsy and should be referred to an epilepsy center for evaluation including possible surgery
Recognizing drug-resistant epilepsy and referring to an epilepsy center is most accurate because failure to achieve seizure freedom after adequate trials of two or more appropriate antiseizure medications defines drug resistance, and such patients warrant specialized evaluation for options including epilepsy surgery, devices, or dietary therapy. Comprehensive reassessment can identify treatable causes. Endlessly escalating the same ineffective drugs is unhelpful, assuming the events are psychogenic without evaluation is unjustified, and concluding that nothing more can be done overlooks effective nonpharmacologic options.
- A 35-year-old woman taking valproate for epilepsy plans to become pregnant. Considering fetal risk, which adjustment to her seizure management is most appropriate during preconception counseling?
- Discuss switching to a lower-teratogenic-risk antiseizure medication and ensure folic acid supplementation
- Continue valproate unchanged because seizure control overrides all other concerns
- Stop all antiseizure medication entirely before conception
- Add a second high-dose antiseizure medication to be safe
Correct answer: Discuss switching to a lower-teratogenic-risk antiseizure medication and ensure folic acid supplementation
Discussing a switch to a lower-teratogenic-risk antiseizure medication and ensuring folic acid supplementation is most appropriate because valproate carries a high risk of neural tube defects and neurodevelopmental harm, so preconception planning aims to use the least teratogenic effective agent at the lowest dose while maintaining seizure control. Proactive medication review reduces fetal risk. Continuing valproate unchanged ignores its established teratogenicity, abruptly stopping all therapy risks dangerous seizures including status epilepticus, and adding another high-dose agent increases exposure without justification.
- A 45-year-old man is brought in after a witnessed episode of sudden loss of consciousness while standing. Bystanders report he was pale and limp, recovered fully within seconds, and had no confusion afterward; brief jerking lasted only a few seconds at the end. Which feature most favors syncope rather than a generalized seizure?
- A prolonged postictal period of confusion lasting many minutes
- Rapid full recovery of orientation almost immediately after the event
- Tongue biting along the lateral tongue
- Head turning and sustained rhythmic convulsions for several minutes
Correct answer: Rapid full recovery of orientation almost immediately after the event
Rapid, full recovery of orientation almost immediately after the event most favors syncope because transient global cerebral hypoperfusion causes brief loss of consciousness with prompt return to baseline, often with pallor and only a few seconds of myoclonic jerks. A short event without lasting confusion is typical of syncope. A prolonged confused postictal period, lateral tongue biting, and sustained rhythmic convulsions over minutes are features that instead point toward a generalized seizure.
- A 26-year-old woman with myasthenia gravis develops increasing difficulty breathing and swallowing over two days, with a weak cough and shallow breaths, in the setting of a recent respiratory infection. Which intervention is the most appropriate immediate priority?
- Reassure and increase her oral pyridostigmine at home
- Start an oral corticosteroid taper to begin in one week
- Assess and support respiratory status with close monitoring and readiness for ventilation
- Schedule elective outpatient pulmonary function testing
Correct answer: Assess and support respiratory status with close monitoring and readiness for ventilation
Assessing and supporting respiratory status with close monitoring and readiness for mechanical ventilation is the most appropriate immediate priority because worsening bulbar and respiratory weakness signals a myasthenic crisis, a life-threatening exacerbation of neuromuscular respiratory failure often triggered by infection. Securing the airway and breathing comes first, alongside treatments such as plasma exchange or immunoglobulin. Increasing oral medication at home, a delayed steroid taper, and elective outpatient testing all dangerously underestimate an evolving respiratory emergency.
- A 40-year-old man with poorly controlled human immunodeficiency virus infection and a very low CD4 count presents with two weeks of headache, low-grade fever, and a new focal deficit. Contrast brain imaging shows multiple ring-enhancing lesions. Which diagnosis is among the most likely causes of this finding in this setting?
- Migraine with aura
- Idiopathic intracranial hypertension
- Benign paroxysmal positional vertigo
- Cerebral toxoplasmosis
Correct answer: Cerebral toxoplasmosis
Cerebral toxoplasmosis is among the most likely causes because multiple ring-enhancing brain lesions with subacute headache, fever, and focal deficits in a person with advanced human immunodeficiency virus infection and a low CD4 count classically reflect reactivation toxoplasmosis, which is often treated empirically while excluding alternatives such as central nervous system lymphoma. The immunocompromised context is key. Migraine and benign positional vertigo do not produce enhancing brain lesions, and idiopathic intracranial hypertension causes raised pressure and papilledema without focal ring-enhancing masses.
- A 67-year-old man develops the sudden onset of vertigo, difficulty swallowing, hoarseness, ipsilateral facial numbness, and contralateral loss of pain and temperature sensation on the body, with limb ataxia. Which vascular territory is most likely responsible for this brainstem stroke syndrome?
- Lateral medulla supplied by the vertebral or posterior inferior cerebellar artery
- Anterior cerebral artery territory
- Middle cerebral artery territory
- Lacunar infarct of the internal capsule
Correct answer: Lateral medulla supplied by the vertebral or posterior inferior cerebellar artery
The lateral medulla supplied by the vertebral or posterior inferior cerebellar artery is most likely responsible because the combination of vertigo, dysphagia, hoarseness, ipsilateral facial sensory loss, crossed body pain and temperature loss, and ataxia constitutes the lateral medullary syndrome from posterior circulation ischemia. The crossed sensory pattern localizes to the brainstem. An anterior cerebral artery stroke causes contralateral leg-predominant weakness, a middle cerebral artery stroke produces cortical signs such as aphasia and face-arm weakness, and a pure lacunar capsular infarct causes isolated motor or sensory deficits without these brainstem features.
- A 50-year-old man with no history of headaches develops a new daily headache that is worse when lying flat and in the early morning, sometimes waking him, and is accompanied by nausea and transient blurring of vision when he bends over. Which concern most warrants urgent neuroimaging in this patient?
- Tension-type headache from work stress
- A space-occupying lesion causing raised intracranial pressure
- Caffeine-withdrawal headache
- Episodic migraine without aura
Correct answer: A space-occupying lesion causing raised intracranial pressure
A space-occupying lesion causing raised intracranial pressure most warrants urgent neuroimaging because a new headache in an older adult that is positional, worse when recumbent and in the early morning, wakes the patient, and is associated with nausea and transient visual obscurations is a red-flag pattern suggesting a mass and elevated pressure. These features demand prompt imaging. Tension-type and caffeine-withdrawal headaches lack these alarming positional and pressure features, and episodic migraine without aura is a primary disorder that would not typically present de novo this way at this age.
- A 22-year-old man sustains a head injury and briefly loses consciousness, then recovers and converses normally during a lucid interval, only to deteriorate over the next hour with worsening headache, vomiting, and progressive drowsiness. Imaging shows a lens-shaped extra-axial collection. Which diagnosis best explains this course?
- Chronic subdural hematoma
- Ischemic lacunar stroke
- Epidural hematoma
- Subarachnoid hemorrhage from an aneurysm
Correct answer: Epidural hematoma
Epidural hematoma best explains this course because a head injury with a brief loss of consciousness followed by a lucid interval and then rapid deterioration, with a biconvex lens-shaped collection on imaging, reflects arterial bleeding between the skull and dura that expands quickly and threatens herniation. The classic lucid interval and lens shape are characteristic. A chronic subdural hematoma evolves gradually over weeks with a crescent shape, a lacunar stroke is ischemic without trauma, and aneurysmal subarachnoid hemorrhage presents with a thunderclap headache rather than this post-traumatic lucid-interval pattern.
- A 79-year-old man on warfarin with a recent minor fall presents with two weeks of gradually worsening headache, mild confusion, and unsteady gait. Imaging shows a crescent-shaped collection over the cerebral convexity with mild midline shift. Which diagnosis best fits this gradually evolving picture?
- Acute epidural hematoma
- Transient ischemic attack
- Bacterial meningitis
- Chronic subdural hematoma
Correct answer: Chronic subdural hematoma
Chronic subdural hematoma best fits because an older anticoagulated patient with a minor head injury who develops insidious headache, cognitive change, and gait instability over weeks, with a crescent-shaped extra-axial collection, has slow venous bridging-vein bleeding that gradually accumulates. Advanced age, brain atrophy, and anticoagulation are major risk factors. An acute epidural hematoma evolves rapidly with a lens shape, a transient ischemic attack causes brief focal deficits without a collection, and bacterial meningitis presents acutely with fever and meningismus rather than this slow crescentic hemorrhage.
- A 25-year-old man with poorly controlled epilepsy is found at home in continuous convulsive seizures. After benzodiazepines fail to stop the seizures and a second-line antiseizure agent is loaded without success, the seizures persist. Which characterization and next step is most appropriate?
- This is refractory status epilepticus requiring continuous anesthetic infusion with intensive care monitoring
- No further treatment is needed because seizures always self-terminate
- Oral medications at home are sufficient management
- The priority is immediate carotid imaging before any further treatment
Correct answer: This is refractory status epilepticus requiring continuous anesthetic infusion with intensive care monitoring
Recognizing refractory status epilepticus and escalating to a continuous anesthetic infusion with intensive care monitoring is most appropriate because status epilepticus that continues despite a benzodiazepine and an adequate second-line agent requires aggressive treatment, typically with continuous infusions such as midazolam or propofol and electroencephalographic monitoring. Prolonged seizures cause neuronal injury and systemic complications. Assuming self-termination is dangerous, oral home medications cannot control active status epilepticus, and carotid imaging is irrelevant to halting the ongoing convulsions.
- A 45-year-old woman recovering from an ischemic stroke is found to have a recently diagnosed nonvalvular atrial fibrillation as the presumed embolic source. For long-term secondary prevention of recurrent cardioembolic stroke in this patient, which therapy is most appropriate?
- Aspirin monotherapy alone
- Long-term oral anticoagulation
- No therapy because the stroke has already occurred
- Lifelong corticosteroids
Correct answer: Long-term oral anticoagulation
Long-term oral anticoagulation is most appropriate because a cardioembolic stroke attributed to nonvalvular atrial fibrillation is best prevented from recurring with therapeutic anticoagulation, which is more effective than antiplatelet therapy for this mechanism. Targeting the cardiac embolic source addresses the cause. Aspirin alone provides inferior protection against cardioembolism, withholding therapy leaves a high recurrence risk, and corticosteroids have no role in stroke prevention. This contrasts with noncardioembolic atherosclerotic stroke, which is managed with antiplatelet therapy.
- A 38-year-old woman with relapsing-remitting multiple sclerosis on a highly effective monoclonal antibody disease-modifying therapy develops new subacute cognitive and behavioral changes with progressive focal deficits over weeks, and imaging shows an expanding white matter lesion unlike her prior plaques. Which serious complication of immunomodulatory therapy must be considered?
- A simple multiple sclerosis relapse requiring only a steroid course
- Migraine with prolonged aura
- Progressive multifocal leukoencephalopathy from JC virus reactivation
- Carpal tunnel syndrome
Correct answer: Progressive multifocal leukoencephalopathy from JC virus reactivation
Progressive multifocal leukoencephalopathy from JC virus reactivation must be considered because certain highly effective immunomodulatory multiple sclerosis therapies increase the risk of this opportunistic brain infection, which presents with subacute progressive cognitive, behavioral, and focal neurologic decline and an enlarging white matter lesion distinct from typical demyelinating plaques. Prompt recognition and stopping the offending drug are critical. A routine relapse would resemble prior attacks, migraine with aura is transient and reversible, and carpal tunnel syndrome is a focal entrapment unrelated to this central process.
- A 31-year-old woman at 26 weeks of gestation has a routine 1-hour 50-gram oral glucose challenge result that is elevated. A follow-up 3-hour 100-gram oral glucose tolerance test shows two abnormal values. What is the most appropriate initial management of her newly identified gestational diabetes?
- Begin basal-bolus insulin immediately for all patients
- Start medical nutrition therapy with carbohydrate-controlled diet and exercise, with glucose self-monitoring
- Initiate metformin and discontinue all dietary counseling
- Defer any intervention until the third trimester
Correct answer: Start medical nutrition therapy with carbohydrate-controlled diet and exercise, with glucose self-monitoring
Starting medical nutrition therapy with a carbohydrate-controlled diet, physical activity, and glucose self-monitoring is correct because lifestyle modification is the first-line treatment for gestational diabetes, with pharmacotherapy added only if glucose targets are not met. Immediate basal-bolus insulin for everyone is unnecessary before a diet trial, metformin alone while abandoning nutrition counseling skips the foundational intervention, and deferring management leaves hyperglycemia untreated and risks fetal harm.
- A 28-year-old woman with well-controlled gestational diabetes managed by diet delivers a healthy infant. At her postpartum visit she asks whether any further testing is needed. Which recommendation is most appropriate?
- No further glucose testing is needed because the diabetes resolved at delivery
- Lifelong daily insulin should be continued
- A 75-gram oral glucose tolerance test at 4 to 12 weeks postpartum to screen for persistent diabetes or prediabetes
- An immediate hemoglobin A1c on the day of delivery is sufficient for all future screening
Correct answer: A 75-gram oral glucose tolerance test at 4 to 12 weeks postpartum to screen for persistent diabetes or prediabetes
Performing a 75-gram oral glucose tolerance test at 4 to 12 weeks postpartum is correct because women with gestational diabetes have a high lifetime risk of type 2 diabetes and require postpartum reclassification and ongoing periodic screening. Assuming the abnormality fully resolves ignores that elevated risk, lifelong insulin is not indicated when glucose normalizes, and a single peripartum A1c does not substitute for structured postpartum and long-term surveillance.
- A 23-year-old woman requests emergency contraception 3 days after a single episode of unprotected intercourse. She weighs 95 kilograms and wants the most effective option available. Which choice is the most effective method of emergency contraception in this situation?
- A single dose of levonorgestrel
- Insertion of a copper intrauterine device
- Oral combined estrogen-progestin pills
- Watchful waiting until the next menses
Correct answer: Insertion of a copper intrauterine device
Insertion of a copper intrauterine device is correct because it is the most effective form of emergency contraception, remains highly effective up to 5 days after intercourse, and is not diminished by higher body weight. Levonorgestrel is less effective overall and its efficacy declines with higher weight, the older combined estrogen-progestin regimen is less effective and causes more nausea, and watchful waiting offers no protection.
- A 35-year-old woman in a long-term mutually monogamous relationship has completed childbearing and requests permanent contraception. She wants to understand the most reliable way to assess whether a male partner's vasectomy has been effective. Which statement is most accurate?
- A post-vasectomy semen analysis confirming azoospermia is required before relying on it for contraception
- Vasectomy provides immediate sterility on the day of the procedure
- Effectiveness can be assumed after one week with no testing
- A blood testosterone level confirms procedural success
Correct answer: A post-vasectomy semen analysis confirming azoospermia is required before relying on it for contraception
Confirming azoospermia with a post-vasectomy semen analysis before relying on it is correct because residual sperm persist for weeks to months, so the couple must use another method until clearance is documented. Vasectomy is not immediately effective, an arbitrary one-week interval without testing risks unintended pregnancy, and testosterone levels are unaffected by vasectomy and do not verify success.
- A 52-year-old woman reports frequent hot flashes and night sweats that disrupt her sleep and daily function. She has an intact uterus, no history of breast cancer or thromboembolism, and no cardiovascular contraindications, and she is within a few years of her final menstrual period. Which therapy is the most effective treatment for her vasomotor symptoms?
- Estrogen combined with a progestogen
- A low-dose aspirin regimen
- Vaginal estrogen cream only
- Oral calcium and vitamin D
Correct answer: Estrogen combined with a progestogen
Systemic estrogen combined with a progestogen is correct because estrogen is the most effective treatment for bothersome vasomotor symptoms, and a progestogen is added in a woman with an intact uterus to protect against endometrial hyperplasia. Aspirin does not relieve hot flashes, low-dose vaginal estrogen treats genitourinary symptoms rather than systemic vasomotor symptoms, and calcium with vitamin D supports bone health but does not reduce hot flashes.
- A 49-year-old woman with bothersome hot flashes has a personal history of estrogen-receptor-positive breast cancer, which makes systemic estrogen therapy inappropriate. Which nonhormonal option has the best evidence for reducing vasomotor symptoms in this patient?
- A daily multivitamin
- A selective serotonin or serotonin-norepinephrine reuptake inhibitor
- Routine systemic antibiotics
- A proton pump inhibitor
Correct answer: A selective serotonin or serotonin-norepinephrine reuptake inhibitor
A selective serotonin or serotonin-norepinephrine reuptake inhibitor is correct because these agents are evidence-based nonhormonal treatments for vasomotor symptoms and are appropriate when estrogen is contraindicated, as in breast cancer survivors. A multivitamin does not relieve hot flashes, antibiotics have no role in vasomotor symptoms, and a proton pump inhibitor treats acid-related disease unrelated to menopausal symptoms.
- A 26-year-old woman presents with chronic pelvic pain, painful periods, and pain with intercourse that have worsened over several years, and she reports difficulty conceiving. Pelvic examination reveals tender uterosacral nodularity. Which diagnosis best explains this constellation of findings?
- Endometriosis
- Bacterial vaginosis
- Functional ovarian cyst
- Uterine prolapse
Correct answer: Endometriosis
Endometriosis is correct because cyclic and chronic pelvic pain, dyspareunia, dysmenorrhea, infertility, and tender uterosacral nodularity together form the classic presentation of ectopic endometrial tissue. Bacterial vaginosis causes vaginal discharge rather than this pain and nodularity pattern, a functional ovarian cyst typically produces acute self-limited pain, and uterine prolapse causes pressure and bulge symptoms rather than this picture.
- A 30-year-old woman with biopsy-confirmed endometriosis has dysmenorrhea and pelvic pain but does not currently desire pregnancy. After a trial of nonsteroidal anti-inflammatory drugs provides inadequate relief, which medical therapy is an appropriate next step for symptom control?
- Empiric broad-spectrum antibiotics
- Combined hormonal contraceptives or a progestin to suppress cyclic activity
- Systemic corticosteroids tapered over a week
- High-dose vitamin C supplementation
Correct answer: Combined hormonal contraceptives or a progestin to suppress cyclic activity
Combined hormonal contraceptives or a progestin is correct because hormonal suppression of cyclic endometrial activity is a mainstay of medical management for endometriosis-related pain when analgesics alone are insufficient. Antibiotics treat infection rather than endometriosis, systemic corticosteroids are not a standard therapy for this condition, and vitamin C does not control endometriosis symptoms.
- A 24-year-old sexually active woman presents with lower abdominal pain, fever, mucopurulent cervical discharge, and cervical motion tenderness with adnexal tenderness on examination. Her pregnancy test is negative and she is hemodynamically stable, tolerating oral intake. Which management is most appropriate for this presentation of pelvic inflammatory disease?
- Outpatient empiric antibiotic therapy covering Neisseria gonorrhoeae, Chlamydia trachomatis, and anaerobes
- Observation alone with no antibiotics
- Immediate total hysterectomy
- A single dose of oral antifungal therapy
Correct answer: Outpatient empiric antibiotic therapy covering Neisseria gonorrhoeae, Chlamydia trachomatis, and anaerobes
Outpatient empiric antibiotics covering Neisseria gonorrhoeae, Chlamydia trachomatis, and anaerobes is correct because a clinically stable woman with pelvic inflammatory disease can be treated as an outpatient with broad regimens that prevent infertility and chronic pain. Observation without antibiotics risks tubal damage, hysterectomy is far too aggressive for an infection treatable with antibiotics, and antifungal therapy does not address the responsible bacteria.
- A 27-year-old woman treated 24 hours ago for pelvic inflammatory disease now has worsening fever, increasing right-sided pelvic pain, and a palpable tender adnexal mass, and pelvic ultrasound shows a complex multiloculated fluid collection. What does this finding most likely represent?
- Expected improvement on therapy
- A normal ovarian follicle
- A tubo-ovarian abscess requiring hospitalization and possible drainage
- Resolution of the infection
Correct answer: A tubo-ovarian abscess requiring hospitalization and possible drainage
A tubo-ovarian abscess requiring hospitalization and possible drainage is correct because a worsening clinical course with a tender adnexal mass and a complex multiloculated collection on imaging signals abscess formation complicating pelvic inflammatory disease. This is not expected improvement, the imaging is not a normal follicle, and clinical deterioration is the opposite of resolution.
- A 58-year-old postmenopausal woman reports vaginal dryness, irritation, and pain with intercourse, with no abnormal bleeding. Examination shows pale, thin, dry vaginal tissue with loss of rugae. She has a history of estrogen-receptor-positive breast cancer. Which first-line management is most appropriate for her genitourinary symptoms?
- Systemic high-dose oral estrogen
- Empiric oral antibiotics
- Combined oral contraceptive pills
- Nonhormonal vaginal moisturizers and lubricants
Correct answer: Nonhormonal vaginal moisturizers and lubricants
Nonhormonal vaginal moisturizers and lubricants are correct because they are the recommended first-line therapy for genitourinary syndrome of menopause and are especially appropriate when estrogen is best avoided, as in a breast cancer survivor. Systemic high-dose estrogen is inappropriate and unnecessary for localized symptoms in this patient, antibiotics treat infection rather than atrophy, and combined oral contraceptives are not used for this indication in a postmenopausal woman.
- A 25-year-old woman who is 8 weeks pregnant presents with vaginal bleeding and lower abdominal cramping. On examination the cervical os is closed, and transvaginal ultrasound shows an intrauterine gestation with cardiac activity. Which term best describes this clinical picture?
- Incomplete abortion
- Missed abortion
- Septic abortion
- Threatened abortion
Correct answer: Threatened abortion
Threatened abortion is correct because vaginal bleeding with a closed cervical os and a viable intrauterine pregnancy on ultrasound defines this entity, in which the pregnancy may still continue. An incomplete abortion involves passage of some products with an open os, a missed abortion involves a nonviable pregnancy retained without cardiac activity, and a septic abortion includes signs of intrauterine infection, none of which fit this presentation.
- A 33-year-old woman who is 16 weeks pregnant by dates is found to have a uterus larger than expected, a markedly elevated beta-hCG, and an ultrasound showing a heterogeneous intrauterine mass with multiple cystic spaces and no fetus. She also reports hyperemesis and early hypertension. Which diagnosis does this picture most strongly suggest?
- A normal twin gestation
- A simple ovarian cyst
- A subchorionic hematoma
- A complete hydatidiform mole
Correct answer: A complete hydatidiform mole
A complete hydatidiform mole is correct because a uterus large for dates, a strikingly elevated beta-hCG, a snowstorm-like intrauterine mass without a fetus, and early hyperemesis and hypertension are classic for molar gestation. A normal twin pregnancy would show two fetuses, a simple ovarian cyst is an adnexal rather than intrauterine finding, and a subchorionic hematoma does not produce these markedly elevated hCG levels or the characteristic mass.
- A 40-year-old woman undergoing evaluation for difficulty conceiving after 12 months of regular unprotected intercourse asks which initial test best assesses whether she is ovulating. Which test most directly confirms ovulation?
- A serum prolactin level
- A fasting glucose level
- A mid-luteal phase serum progesterone level
- A complete blood count
Correct answer: A mid-luteal phase serum progesterone level
A mid-luteal phase serum progesterone level is correct because a rise in progesterone roughly 7 days before expected menses confirms that ovulation has occurred and is a core part of the initial infertility evaluation. A prolactin level screens for an endocrine cause of anovulation rather than confirming ovulation directly, and fasting glucose and a complete blood count do not assess ovulatory status.
- A 58-year-old man with a 40-pack-year smoking history asks whether he qualifies for lung cancer screening. He quit smoking 8 years ago and is otherwise healthy. Which screening test and threshold are currently recommended for an asymptomatic person at high risk?
- Annual chest radiograph for all adults older than 55 years regardless of smoking history
- Sputum cytology every 6 months for current and former smokers
- Low-dose computed tomography of the chest annually for adults 50 to 80 years with a 20-pack-year history who currently smoke or quit within the past 15 years
- Positron emission tomography of the chest every 2 years for adults with any tobacco history
Correct answer: Low-dose computed tomography of the chest annually for adults 50 to 80 years with a 20-pack-year history who currently smoke or quit within the past 15 years
Annual low-dose CT of the chest is the recommended modality for adults 50 to 80 years with a 20-pack-year smoking history who currently smoke or quit within the past 15 years. This patient at age 58 with a 40-pack-year history who quit 8 years ago meets every criterion. Chest radiography has been shown ineffective for screening, sputum cytology is not a screening tool, and routine PET screening is not recommended.
- A 64-year-old woman presents with cough and weight loss. Imaging reveals a central lung mass, and she is found to have a serum sodium of 119 mEq/L with low serum osmolality, elevated urine osmolality, and euvolemia. Which lung cancer histology is most classically associated with this paraneoplastic finding?
- Small cell lung carcinoma
- Squamous cell carcinoma
- Bronchioloalveolar adenocarcinoma
- Pulmonary carcinoid of the appendix
Correct answer: Small cell lung carcinoma
Small cell lung carcinoma is the histology most classically linked to the syndrome of inappropriate antidiuretic hormone secretion, producing euvolemic hyponatremia with low serum osmolality and inappropriately concentrated urine, as seen here. Squamous cell carcinoma is instead associated with hypercalcemia from parathyroid hormone-related peptide. The other options do not characteristically cause this presentation.
- A 70-year-old man with a long smoking history is found to have a 3-cm peripheral lung nodule with biopsy-proven non-small cell lung cancer and no evidence of nodal or distant spread. What is the most appropriate next step for accurate staging before definitive treatment?
- Immediate lobectomy without further imaging
- Empiric platinum-based chemotherapy for presumed advanced disease
- Positron emission tomography-computed tomography and brain magnetic resonance imaging to evaluate for occult metastatic disease
- Repeat chest computed tomography in 12 months
Correct answer: Positron emission tomography-computed tomography and brain magnetic resonance imaging to evaluate for occult metastatic disease
PET-CT plus brain MRI is the appropriate next step, because accurate staging requires excluding occult nodal and distant metastases that would change a patient from a curative surgical candidate to systemic therapy. Proceeding directly to lobectomy risks operating on undetected metastatic disease, empiric chemotherapy is inappropriate for potentially localized disease, and simple interval CT follow-up of a biopsy-proven cancer delays curative treatment.
- A 55-year-old never-smoker is diagnosed with metastatic lung adenocarcinoma. Molecular testing of the tumor reveals an activating EGFR mutation. Which treatment approach is most appropriate as initial systemic therapy?
- Platinum-doublet chemotherapy alone
- An oral EGFR tyrosine kinase inhibitor
- Whole-brain radiation therapy
- Immediate surgical metastasectomy of all lesions
Correct answer: An oral EGFR tyrosine kinase inhibitor
An oral EGFR tyrosine kinase inhibitor is the preferred first-line therapy when an activating EGFR mutation is identified, producing higher response rates and better tolerability than cytotoxic chemotherapy. Platinum-doublet chemotherapy is reserved for tumors without a targetable driver, whole-brain radiation is not first-line systemic therapy, and surgery is not appropriate for widely metastatic disease.
- A 50-year-old woman with no symptoms asks at what age and how often she should begin mammography for average-risk breast cancer screening. She has no family history and no genetic risk factors. Which recommendation reflects current average-risk screening guidance?
- Begin mammography only after age 60 and only if symptoms develop
- Perform screening breast magnetic resonance imaging annually starting at age 30
- No imaging is needed if monthly self-examination is performed
- Begin screening mammography at age 40 and screen every 1 to 2 years
Correct answer: Begin screening mammography at age 40 and screen every 1 to 2 years
Beginning screening mammography at age 40 with screening every 1 to 2 years reflects current average-risk guidance. Waiting until age 60 misses years of detectable early cancers, MRI screening starting at age 30 is reserved for high-risk women such as known BRCA carriers, and self-examination alone is not a substitute for mammographic screening.
- A 48-year-old woman has a newly diagnosed invasive ductal breast carcinoma. Pathology reports the tumor is estrogen receptor positive, progesterone receptor positive, and HER2 negative. Which class of systemic therapy is most appropriate to reduce her recurrence risk after surgery?
- Trastuzumab-based HER2-directed therapy
- Single-agent immune checkpoint inhibitor monotherapy
- Endocrine therapy such as tamoxifen or an aromatase inhibitor
- No systemic therapy because hormone-positive tumors do not recur
Correct answer: Endocrine therapy such as tamoxifen or an aromatase inhibitor
Endocrine therapy with tamoxifen or an aromatase inhibitor is appropriate adjuvant therapy for a hormone receptor-positive, HER2-negative breast cancer, blocking estrogen-driven growth to lower recurrence. HER2-directed trastuzumab is indicated only for HER2-positive tumors, checkpoint inhibitor monotherapy is not the standard adjuvant approach here, and hormone-positive tumors do carry a meaningful recurrence risk that adjuvant therapy reduces.
- A 42-year-old woman is found on biopsy to have a breast cancer that is estrogen receptor negative, progesterone receptor negative, and HER2 negative. Which statement best characterizes this tumor subtype?
- It is the most indolent subtype and rarely requires any systemic treatment
- It is triple-negative breast cancer, which does not respond to endocrine or HER2-directed therapy and is typically treated with chemotherapy
- It is best treated with an aromatase inhibitor alone
- It is HER2-driven and should receive trastuzumab
Correct answer: It is triple-negative breast cancer, which does not respond to endocrine or HER2-directed therapy and is typically treated with chemotherapy
A tumor negative for estrogen receptor, progesterone receptor, and HER2 is triple-negative breast cancer, which lacks targets for endocrine or HER2-directed agents and is generally managed with cytotoxic chemotherapy, sometimes with immunotherapy. It tends to be more aggressive rather than indolent, an aromatase inhibitor requires hormone receptor positivity, and trastuzumab requires HER2 positivity.
- A 60-year-old woman reports a personal history of breast cancer at age 38 and an extensive family history of breast and ovarian cancer in first-degree relatives. Which step is most appropriate in her evaluation?
- Reassure her that early-onset cancer does not increase the chance of an inherited mutation
- Order serum tumor markers as the primary means of assessing hereditary risk
- Begin prophylactic chemotherapy regardless of genetic status
- Refer for genetic counseling and consider testing for BRCA1 and BRCA2 mutations
Correct answer: Refer for genetic counseling and consider testing for BRCA1 and BRCA2 mutations
Referral for genetic counseling and BRCA1/BRCA2 testing is appropriate given early-onset breast cancer and a strong family history of breast and ovarian cancer, which markedly raise the probability of a hereditary mutation that affects surveillance and risk-reduction options. Early-onset disease increases rather than decreases inherited risk, serum tumor markers do not assess germline mutations, and prophylactic chemotherapy is not a risk-reduction strategy.
- A 52-year-old man asks when to begin colorectal cancer screening. He has no symptoms, no inflammatory bowel disease, and no family history of colorectal cancer. According to current average-risk guidance, when should screening begin and what is one acceptable modality?
- Begin at age 65 with colonoscopy only
- Begin at age 30 with annual computed tomography of the abdomen
- Begin at age 45 with colonoscopy or a stool-based test such as a fecal immunochemical test
- Screening is unnecessary unless rectal bleeding occurs
Correct answer: Begin at age 45 with colonoscopy or a stool-based test such as a fecal immunochemical test
Average-risk colorectal cancer screening now begins at age 45, and acceptable options include colonoscopy or a stool-based test such as the fecal immunochemical test. Waiting until age 65 misses years of preventable cancers, routine abdominal CT is not a screening tool, and waiting for symptoms such as bleeding defeats the purpose of screening for an often asymptomatic early cancer.
- A 68-year-old man has iron deficiency anemia and undergoes colonoscopy, which reveals a near-obstructing mass in the ascending colon; biopsy confirms adenocarcinoma without evidence of metastasis. Which serum marker is most useful to follow after curative resection to monitor for recurrence?
- Alpha-fetoprotein
- Carcinoembryonic antigen
- Cancer antigen 125
- Prostate-specific antigen
Correct answer: Carcinoembryonic antigen
Carcinoembryonic antigen is the marker followed serially after curative resection of colorectal cancer, where a rising level can signal recurrence before it is clinically evident. Alpha-fetoprotein is used in hepatocellular and germ cell tumors, cancer antigen 125 in ovarian cancer, and prostate-specific antigen in prostate cancer, none of which apply to colorectal surveillance.
- A 45-year-old woman has multiple family members across three generations with colorectal and endometrial cancers diagnosed at young ages. Tumor testing in an affected relative shows microsatellite instability. Which inherited condition is most consistent with this pattern?
- Lynch syndrome (hereditary nonpolyposis colorectal cancer)
- Familial adenomatous polyposis with hundreds of colonic polyps
- Sporadic colorectal cancer with no inherited basis
- Peutz-Jeghers syndrome with mucocutaneous pigmentation
Correct answer: Lynch syndrome (hereditary nonpolyposis colorectal cancer)
Lynch syndrome best fits a multigenerational pattern of early-onset colorectal and endometrial cancers with tumor microsatellite instability, reflecting defective DNA mismatch repair. Familial adenomatous polyposis produces hundreds to thousands of polyps, a sporadic origin is inconsistent with the strong inherited pattern, and Peutz-Jeghers is defined by hamartomatous polyps and mucocutaneous pigmentation rather than this profile.
- A 63-year-old man undergoes colonoscopy that removes a single 6-mm tubular adenoma with low-grade dysplasia and no high-risk features. Bowel preparation was adequate and the cecum was reached. What is the most appropriate interval for the next surveillance colonoscopy?
- In 7 to 10 years
- In 3 months
- In 6 months
- Never repeat colonoscopy after any polyp
Correct answer: In 7 to 10 years
A surveillance interval of 7 to 10 years is appropriate after complete removal of one or two small tubular adenomas with low-grade dysplasia, which carry a low risk of advanced neoplasia. Intervals of 3 to 6 months are reserved for incomplete resection or far higher-risk findings, and discontinuing surveillance entirely is incorrect because adenomas confer ongoing colorectal cancer risk.
- A 24-year-old man with a bulky, rapidly proliferating Burkitt lymphoma is admitted to begin chemotherapy. Two days after the first dose, he develops hyperkalemia, hyperphosphatemia, hyperuricemia, hypocalcemia, and acute kidney injury. Which oncologic emergency is occurring?
- Superior vena cava syndrome
- Hypercalcemia of malignancy
- Spinal cord compression
- Tumor lysis syndrome
Correct answer: Tumor lysis syndrome
Tumor lysis syndrome is occurring, defined by the metabolic tetrad of hyperkalemia, hyperphosphatemia, hyperuricemia, and hypocalcemia after massive tumor cell breakdown in a highly proliferative cancer such as Burkitt lymphoma. Superior vena cava syndrome causes facial and arm swelling, hypercalcemia of malignancy does not raise potassium and phosphate this way, and cord compression presents with neurologic deficits rather than this electrolyte pattern.
- A patient with a high-grade lymphoma and a large tumor burden is about to start chemotherapy. To reduce the risk of tumor lysis syndrome, which prophylactic measures are most appropriate?
- Fluid restriction and a low-dose thiazide diuretic
- Routine potassium and phosphate supplementation before treatment
- Calcium gluconate infusion to all patients regardless of laboratory values
- Aggressive intravenous hydration and a urate-lowering agent such as allopurinol or rasburicase
Correct answer: Aggressive intravenous hydration and a urate-lowering agent such as allopurinol or rasburicase
Aggressive intravenous hydration combined with a urate-lowering agent such as allopurinol or rasburicase is the cornerstone of tumor lysis syndrome prophylaxis, maintaining urine flow and controlling uric acid before cell breakdown peaks. Fluid restriction worsens the risk, supplementing potassium and phosphate is harmful because those rise dangerously, and routine calcium is given only for symptomatic hypocalcemia rather than empirically.
- A patient receiving treatment for acute leukemia develops established tumor lysis syndrome with a rapidly rising uric acid level and impending renal compromise. Which agent works by enzymatically converting uric acid to a more soluble compound for rapid lowering?
- Allopurinol
- Rasburicase
- Furosemide
- Sevelamer
Correct answer: Rasburicase
Rasburicase is a recombinant urate oxidase that enzymatically converts existing uric acid into allantoin, which is far more soluble and rapidly cleared, making it the agent of choice when uric acid is already high or rising fast. Allopurinol only blocks new uric acid formation and does not remove the existing burden, furosemide is a diuretic, and sevelamer binds phosphate rather than urate.
- A 66-year-old woman with metastatic breast cancer presents with fatigue, constipation, polyuria, and confusion. Laboratory testing shows a markedly elevated serum calcium. What is the most appropriate initial management of this oncologic emergency?
- Fluid restriction and oral calcium carbonate
- Aggressive intravenous isotonic saline followed by an intravenous bisphosphonate
- Immediate hemodialysis for all patients
- High-dose vitamin D supplementation
Correct answer: Aggressive intravenous isotonic saline followed by an intravenous bisphosphonate
Aggressive intravenous isotonic saline to restore volume and enhance calcium excretion, followed by an intravenous bisphosphonate to inhibit bone resorption, is the standard initial management of hypercalcemia of malignancy. Fluid restriction and oral calcium worsen the problem, dialysis is reserved for refractory or renal-failure cases, and vitamin D would further raise calcium.
- A 60-year-old man with known metastatic prostate cancer develops worsening mid-back pain, bilateral leg weakness, and new urinary retention over 48 hours. Which intervention is most critical to perform urgently?
- Outpatient physical therapy referral
- Emergent magnetic resonance imaging of the spine and immediate corticosteroids
- A trial of oral nonsteroidal anti-inflammatory drugs and reassessment in one week
- Routine bone scan scheduled for the following month
Correct answer: Emergent magnetic resonance imaging of the spine and immediate corticosteroids
Emergent spinal MRI with prompt high-dose corticosteroids is critical because progressive back pain with leg weakness and urinary retention in a cancer patient signals malignant spinal cord compression, where delay risks permanent paralysis. Physical therapy, a week of nonsteroidal anti-inflammatory drugs, or a routine future bone scan all dangerously postpone diagnosis and definitive radiation or surgery.
- A 55-year-old man with small cell lung cancer develops facial swelling, distended neck veins, dyspnea, and dilated chest wall veins that are worse when he lies flat. Which condition is the most likely cause?
- Acute pulmonary embolism
- Cardiac tamponade from pericardial effusion
- Superior vena cava syndrome from tumor compression
- Hypercalcemia of malignancy
Correct answer: Superior vena cava syndrome from tumor compression
Superior vena cava syndrome is most likely, presenting with facial and upper-body swelling, distended neck and chest wall veins, and dyspnea from obstruction of venous return, classically caused by a mediastinal malignancy such as small cell lung cancer. Pulmonary embolism does not cause this venous engorgement pattern, tamponade produces muffled heart sounds and pulsus paradoxus, and hypercalcemia presents with neuropsychiatric and gastrointestinal symptoms.
- A 28-year-old man presents with a painless, firm testicular mass. Scrotal ultrasound shows a solid intratesticular lesion. Which serum tumor markers should be obtained as part of the evaluation of a suspected testicular germ cell tumor?
- Carcinoembryonic antigen and cancer antigen 19-9
- Alpha-fetoprotein, beta-human chorionic gonadotropin, and lactate dehydrogenase
- Prostate-specific antigen and cancer antigen 125
- Calcitonin and chromogranin A
Correct answer: Alpha-fetoprotein, beta-human chorionic gonadotropin, and lactate dehydrogenase
Alpha-fetoprotein, beta-human chorionic gonadotropin, and lactate dehydrogenase are the serum markers obtained for a suspected testicular germ cell tumor, aiding diagnosis, staging, and monitoring. Carcinoembryonic antigen and cancer antigen 19-9 relate to gastrointestinal cancers, prostate-specific antigen and cancer antigen 125 to prostate and ovarian cancers, and calcitonin and chromogranin A to thyroid and neuroendocrine tumors.
- A 70-year-old man with metastatic colorectal cancer and a prognosis measured in months has poorly controlled pain and asks about goals of care. Which statement best reflects appropriate palliative oncology practice?
- Palliative care can only begin once all disease-directed therapy has been stopped
- Opioids should be avoided in cancer pain because of addiction risk
- Early integration of palliative care alongside cancer treatment improves symptom control and quality of life
- Palliative care is equivalent to withdrawing all medical treatment
Correct answer: Early integration of palliative care alongside cancer treatment improves symptom control and quality of life
Early integration of palliative care alongside ongoing cancer treatment improves symptom control and quality of life and is recommended for patients with advanced malignancy. Palliative care does not require stopping disease-directed therapy, opioids are appropriate and effective for cancer-related pain, and palliative care is an active approach to comfort rather than withdrawal of all treatment.
- A 72-year-old man is incidentally found to have a prostate-specific antigen of 6 ng/mL, and biopsy reveals low-grade prostate adenocarcinoma confined to the gland. He is otherwise healthy with a long life expectancy and asks about management of localized low-risk disease. Which option is most consistent with current practice?
- Active surveillance with periodic prostate-specific antigen testing and repeat biopsy
- Immediate bilateral orchiectomy for all low-risk disease
- Whole-body chemotherapy as first-line therapy
- No further follow-up is ever needed once the cancer is detected
Correct answer: Active surveillance with periodic prostate-specific antigen testing and repeat biopsy
Active surveillance with periodic prostate-specific antigen monitoring and repeat biopsy is appropriate for many men with low-risk, localized prostate cancer, avoiding overtreatment of an often indolent disease while allowing intervention if progression occurs. Orchiectomy and chemotherapy are not first-line for low-risk localized disease, and abandoning follow-up forgoes the monitoring that makes surveillance safe.
- A 58-year-old woman with chronic hepatitis C cirrhosis is enrolled in a surveillance program. Which approach is recommended to detect hepatocellular carcinoma at a treatable stage?
- Annual chest radiography
- Colonoscopy every 2 years
- Abdominal ultrasound, with or without alpha-fetoprotein, every 6 months
- Serum carcinoembryonic antigen measured monthly
Correct answer: Abdominal ultrasound, with or without alpha-fetoprotein, every 6 months
Surveillance with abdominal ultrasound every 6 months, with or without alpha-fetoprotein, is recommended for patients with cirrhosis to detect hepatocellular carcinoma early. Chest radiography screens for thoracic disease, colonoscopy targets colorectal neoplasia, and carcinoembryonic antigen is not the marker used for hepatocellular carcinoma surveillance.
- A 67-year-old man with widely metastatic melanoma is started on an immune checkpoint inhibitor. Several weeks later he develops profuse watery diarrhea and abdominal pain. Which mechanism best explains this adverse effect?
- A direct cytotoxic effect on intestinal stem cells like classic chemotherapy
- An expected infectious complication of the drug
- A paraneoplastic effect of the melanoma itself
- An immune-related adverse event causing inflammatory colitis
Correct answer: An immune-related adverse event causing inflammatory colitis
Immune checkpoint inhibitors release the brakes on T cells and can trigger immune-related adverse events, of which colitis presenting as diarrhea is a common and potentially serious example, often managed with corticosteroids. These agents are not classic cytotoxic chemotherapy acting on stem cells, the colitis is autoimmune rather than infectious, and it is a drug toxicity rather than a paraneoplastic phenomenon.
- A 60-year-old woman receiving a highly emetogenic chemotherapy regimen reports severe nausea and vomiting in the first 24 hours after each infusion despite no preventive medications. Which approach is most appropriate to reduce chemotherapy-induced nausea and vomiting?
- Prophylactic antiemetics such as a serotonin (5-HT3) receptor antagonist combined with a neurokinin-1 antagonist and dexamethasone
- Withholding antiemetics until vomiting becomes intractable
- A single dose of an antihistamine given only after symptoms start
- Reassurance that nausea after chemotherapy cannot be prevented
Correct answer: Prophylactic antiemetics such as a serotonin (5-HT3) receptor antagonist combined with a neurokinin-1 antagonist and dexamethasone
Prophylactic combination antiemetics, typically a serotonin (5-HT3) receptor antagonist plus a neurokinin-1 antagonist and dexamethasone, are recommended before highly emetogenic chemotherapy because prevention is far more effective than rescue treatment. Waiting for intractable vomiting, relying on a single late antihistamine dose, or assuming nausea is unpreventable all fail to apply established prophylaxis.
- A 55-year-old man undergoing chemotherapy presents with a fever of 38.5 degrees Celsius and an absolute neutrophil count of 400 cells per microliter. Which action is most appropriate?
- Wait for culture results before giving any antibiotics
- Administer oral acetaminophen alone and discharge home
- Delay all evaluation until the next scheduled clinic visit
- Obtain blood cultures and promptly start broad-spectrum empiric antibiotics
Correct answer: Obtain blood cultures and promptly start broad-spectrum empiric antibiotics
Febrile neutropenia is a medical emergency, so the correct action is to obtain blood cultures and immediately begin broad-spectrum empiric antibiotics, because neutropenic patients can deteriorate rapidly from infection. Awaiting culture results, giving only antipyretics and discharging, or deferring evaluation all dangerously delay treatment that must begin within the first hour.
- A 62-year-old man with metastatic non-small cell lung cancer is being considered for an immune checkpoint inhibitor. Testing of his tumor for which biomarker most directly helps predict the likelihood of benefit from this therapy?
- Programmed death-ligand 1 (PD-L1) expression
- Carcinoembryonic antigen level
- Erythrocyte sedimentation rate
- Serum lactate dehydrogenase alone
Correct answer: Programmed death-ligand 1 (PD-L1) expression
Programmed death-ligand 1 (PD-L1) expression is the tumor biomarker used to help predict benefit from checkpoint inhibitor therapy in non-small cell lung cancer, with higher expression generally associated with greater likelihood of response. Carcinoembryonic antigen, the erythrocyte sedimentation rate, and lactate dehydrogenase do not guide checkpoint inhibitor selection in this setting.
- A 49-year-old woman has a screening mammogram showing a suspicious cluster of microcalcifications. What is the most appropriate next step to establish a tissue diagnosis?
- Begin tamoxifen empirically without biopsy
- Repeat the mammogram in 2 years
- Proceed directly to mastectomy without pathology
- Image-guided core needle biopsy of the abnormal area
Correct answer: Image-guided core needle biopsy of the abnormal area
Image-guided core needle biopsy is the appropriate next step to obtain a histologic diagnosis of a suspicious mammographic finding before any treatment decision. Starting tamoxifen without a diagnosis is inappropriate, deferring follow-up for 2 years risks progression of a possible cancer, and mastectomy should never precede pathologic confirmation.
- A 40-year-old woman with newly diagnosed cancer asks how the stage of her disease is determined. Which framework most commonly describes the anatomic extent of a solid tumor for staging purposes?
- The TNM system describing tumor size, regional lymph node involvement, and distant metastasis
- The CHA2DS2-VASc score
- The MELD score
- The CURB-65 score
Correct answer: The TNM system describing tumor size, regional lymph node involvement, and distant metastasis
The TNM system, which classifies the primary tumor size and extent (T), regional lymph node involvement (N), and distant metastasis (M), is the standard framework for staging solid tumors and guiding prognosis and treatment. The CHA2DS2-VASc score estimates stroke risk in atrial fibrillation, the MELD score grades liver disease severity, and CURB-65 assesses pneumonia severity, none of which stage cancer.
- A 70-year-old man with hypertension and carotid atherosclerosis develops sudden, painless, complete loss of vision in his left eye that he describes as a curtain coming down, persisting for the past 40 minutes. On funduscopy the retina appears pale and edematous with a cherry-red spot at the fovea. Which is the most likely diagnosis?
- Central retinal artery occlusion
- Acute angle-closure glaucoma
- Vitreous hemorrhage
- Optic neuritis
Correct answer: Central retinal artery occlusion
Central retinal artery occlusion is the most likely diagnosis because sudden, painless, profound monocular vision loss accompanied by a pale edematous retina and a cherry-red spot at the fovea is the classic picture of acute retinal ischemia, typically embolic from carotid disease, and it is a true ocular emergency analogous to a stroke. Acute angle-closure glaucoma causes a painful red eye with halos and a fixed mid-dilated pupil rather than painless loss with a cherry-red spot, vitreous hemorrhage produces floaters and a loss of the red reflex without a cherry-red spot, and optic neuritis causes subacute vision loss with eye pain on movement and a relative afferent pupillary defect rather than a pale retina with a foveal cherry-red spot.
- A 55-year-old woman with poorly controlled type 2 diabetes is found on dilated examination to have neovascularization of the optic disc and preretinal hemorrhage. She has had progressive blurring of vision. Which stage of disease does this represent and what is the appropriate management priority?
- Nonproliferative diabetic retinopathy requiring no specific eye treatment
- Proliferative diabetic retinopathy requiring prompt referral for laser or anti-VEGF therapy
- Hypertensive retinopathy requiring only blood pressure control
- Age-related macular degeneration requiring antioxidant supplementation
Correct answer: Proliferative diabetic retinopathy requiring prompt referral for laser or anti-VEGF therapy
Proliferative diabetic retinopathy requiring prompt referral for laser or anti-VEGF therapy is correct because the presence of new abnormal vessels on the optic disc and preretinal hemorrhage defines the proliferative stage, which carries a high risk of vitreous hemorrhage and tractional retinal detachment and is treated with panretinal photocoagulation or anti-VEGF injection to preserve sight. Nonproliferative disease shows microaneurysms, dot-blot hemorrhages, and exudates without neovascularization, hypertensive retinopathy produces arteriolar narrowing and flame hemorrhages rather than disc neovascularization, and age-related macular degeneration is characterized by drusen and macular changes rather than the proliferative vascular response of diabetes.
- A 68-year-old woman with diabetes and hypertension reports sudden painless blurring of vision in one eye. Funduscopy shows diffuse retinal hemorrhages in all four quadrants, dilated tortuous veins, and optic disc edema, often described as a blood-and-thunder appearance. Which is the most likely diagnosis?
- Retinitis pigmentosa
- Central retinal artery occlusion
- Central retinal vein occlusion
- Primary open-angle glaucoma
Correct answer: Central retinal vein occlusion
Central retinal vein occlusion is the most likely diagnosis because painless monocular vision loss with widespread retinal hemorrhages across all four quadrants, dilated tortuous veins, and disc edema producing a blood-and-thunder fundus is the hallmark of venous outflow obstruction, which is associated with hypertension, diabetes, and glaucoma. Retinitis pigmentosa causes progressive night blindness with bone-spicule pigmentation rather than acute hemorrhage, central retinal artery occlusion produces a pale retina with a cherry-red spot rather than diffuse hemorrhage, and primary open-angle glaucoma causes chronic painless peripheral field loss without acute fundal hemorrhage.
- A 72-year-old man presents with a painful vesicular rash over the right forehead and the tip of his nose, along with redness and tearing of the right eye. Which finding indicates the greatest risk of ocular involvement requiring urgent ophthalmology referral?
- Vesicles extending below the eyebrow onto the upper eyelid
- Vesicles on the tip of the nose
- Postauricular lymphadenopathy
- Fever and malaise
Correct answer: Vesicles on the tip of the nose
Vesicles on the tip of the nose are the strongest warning sign because this finding, known as Hutchinson sign, reflects involvement of the nasociliary branch of the trigeminal nerve, which also supplies the eye, and it predicts a high likelihood of herpes zoster ophthalmicus with sight-threatening keratitis or uveitis warranting urgent ophthalmologic evaluation and antiviral therapy. Vesicles on the upper eyelid alone, postauricular lymphadenopathy, and systemic symptoms such as fever and malaise can accompany zoster but do not specifically predict the corneal and intraocular involvement signaled by nasociliary nerve disease.
- A 32-year-old woman reports subacute loss of vision in her right eye over several days, accompanied by pain that worsens with eye movement and impaired color perception. Examination reveals a relative afferent pupillary defect in the right eye with a normal-appearing optic disc. Which underlying condition is most strongly associated with this presentation?
- Multiple sclerosis
- Diabetes mellitus
- Giant cell arteritis
- Chronic hypertension
Correct answer: Multiple sclerosis
Multiple sclerosis is the condition most strongly associated with this presentation because subacute monocular vision loss with pain on eye movement, impaired color vision, and a relative afferent pupillary defect with a normal disc describes retrobulbar optic neuritis, which is frequently the presenting demyelinating event of multiple sclerosis. Diabetes causes a microvascular retinopathy rather than painful optic neuritis, giant cell arteritis typically causes sudden painless ischemic optic neuropathy with a pale swollen disc in older patients with systemic symptoms, and chronic hypertension produces arteriolar retinal changes rather than a painful demyelinating optic neuritis in a young adult.
- A 19-year-old college student reports 3 days of sore throat, subjective fever, and difficulty swallowing. He has no cough and no nasal congestion. On examination his temperature is 38.4 C, there is tonsillar swelling with whitish exudate, and tender, enlarged anterior cervical lymph nodes are palpable. Using the Centor criteria to estimate the probability of group A streptococcal pharyngitis, which of the following features in this patient counts toward a higher likelihood of streptococcal infection?
- The presence of cough
- His age of 19 years
- The presence of nasal congestion
- The absence of cough
Correct answer: The absence of cough
The absence of cough is the feature that counts toward streptococcal pharyngitis. The Centor criteria award one point each for tonsillar exudate, tender anterior cervical adenopathy, fever, and absence of cough; the modified McIsaac version adds a point for ages 3 to 14 and subtracts a point for age 45 or older. Cough and nasal congestion suggest a viral cause and do not favor strep, so their presence would not add points. Age 19 falls in the neutral band and neither adds nor subtracts a point. This patient meets four positive Centor features, prompting consideration of rapid antigen testing and treatment.
- A 24-year-old man with a recently untreated streptococcal pharyngitis now has severe unilateral throat pain, a muffled hot-potato voice, drooling, and trismus that limits mouth opening. Examination reveals a swollen, fluctuant left peritonsillar region with the uvula deviated to the right. He is breathing comfortably and is hemodynamically stable. In addition to antibiotics, what is the most appropriate next step in management?
- Outpatient observation with oral analgesics alone
- Needle aspiration or incision and drainage of the collection
- Immediate cricothyrotomy
- Antiviral therapy for suspected herpangina
Correct answer: Needle aspiration or incision and drainage of the collection
Needle aspiration or incision and drainage of the collection is the most appropriate next step for a peritonsillar abscess, alongside antibiotics covering streptococci and oral anaerobes. The hallmark findings are unilateral bulging of the soft palate with uvular deviation away from the affected side, trismus, muffled voice, and drooling, which distinguish it from uncomplicated tonsillitis. Observation with analgesics alone is inadequate for a drainable abscess. Cricothyrotomy is unnecessary because the airway is patent and the patient is breathing comfortably, and antivirals are inappropriate because this is a bacterial suppurative complication rather than a viral process.
- A 31-year-old woman reports recurrent painful swelling of the area just below and in front of her left ear that flares within minutes of eating and then gradually subsides over an hour or two. She has had several such episodes over 2 months and now has a low-grade fever with increased tenderness. Examination shows a swollen, tender left submandibular region, and bimanual palpation of the floor of the mouth reveals a firm, mobile stone near the duct opening with scant cloudy saliva expressed on massage. Which mechanism best explains her postprandial swelling?
- Autoimmune lymphocytic infiltration of the salivary gland
- Obstruction of salivary outflow by a duct calculus
- Malignant ductal carcinoma compressing the gland
- Viral parotid inflammation from mumps
Correct answer: Obstruction of salivary outflow by a duct calculus
Obstruction of salivary outflow by a duct calculus best explains the postprandial swelling. When eating stimulates salivary flow, a stone, most often in the submandibular Wharton duct, blocks drainage and causes rapid painful gland enlargement that subsides as flow ceases; secondary bacterial sialadenitis then produces fever, increased tenderness, and cloudy saliva. Autoimmune lymphocytic infiltration, as in Sjogren disease, causes chronic dryness rather than mealtime swelling. A ductal carcinoma typically presents as a fixed, often painless mass rather than intermittent flow-related swelling. Mumps causes bilateral parotid swelling in an unvaccinated patient and is not triggered by eating or associated with a palpable duct stone.
- A 45-year-old man with a 25-year history of smoking and heavy alcohol use is found on examination to have a firm, nontender, fixed mass in the lateral neck. He also reports a persistent rough patch on the lateral tongue and several weeks of mild odynophagia. Considering the most concerning diagnosis suggested by his risk factors and findings, which next step is most appropriate?
- Reassurance and re-examination in 6 months
- A 10-day course of amoxicillin for presumed lymphadenitis
- Referral for examination of the upper aerodigestive tract with biopsy of the suspicious lesion
- Topical antifungal therapy for presumed oral candidiasis
Correct answer: Referral for examination of the upper aerodigestive tract with biopsy of the suspicious lesion
Referral for examination of the upper aerodigestive tract with biopsy of the suspicious lesion is the most appropriate next step. Tobacco and alcohol are the major risk factors for head and neck squamous cell carcinoma, and a firm fixed neck mass with a nonhealing tongue lesion and odynophagia in an adult is highly concerning for malignancy that requires tissue diagnosis. Reassurance with delayed follow-up risks progression of a potentially curable cancer. Empiric antibiotics are appropriate for clear-cut acute lymphadenitis, not for a hard fixed mass with these red flags. Antifungal therapy treats candidiasis, which presents as removable white plaques rather than a fixed indurated lesion accompanied by a neck mass.
- A 27-year-old woman presents with several days of left ear pain, decreased hearing, and a sensation of fullness following a recent viral upper respiratory infection. On pneumatic otoscopy the left tympanic membrane is bulging and erythematous with reduced mobility, and there is no discharge in the canal. She has no drug allergies and has not taken antibiotics recently. According to current guidelines for acute otitis media in an adult with these findings, which first-line oral antibiotic is most appropriate if antibiotics are prescribed?
- Amoxicillin
- Oral vancomycin
- Ciprofloxacin
- Metronidazole
Correct answer: Amoxicillin
Amoxicillin is the most appropriate first-line oral antibiotic for acute otitis media in a patient without a penicillin allergy or recent antibiotic exposure, with amoxicillin-clavulanate reserved for situations needing broader coverage. The diagnosis rests on a bulging tympanic membrane with impaired mobility on pneumatic otoscopy and signs of middle ear inflammation, as seen here. Oral vancomycin is used for Clostridioides difficile colitis, not otitis media. Ciprofloxacin is not a first-line agent for the typical acute otitis media pathogens in this setting, and metronidazole targets anaerobes and protozoa rather than the usual otitis media organisms.
- A 34-year-old woman tells her internist that for the past two months she has felt persistently sad, has lost interest in activities she used to enjoy, sleeps poorly, has low energy, and finds it hard to concentrate at work. She denies any history of an elevated, expansive mood or decreased need for sleep with increased goal-directed activity. Which diagnosis best fits her presentation?
- Major depressive disorder
- Bipolar I disorder
- Generalized anxiety disorder
- Adjustment disorder with anxious mood
Correct answer: Major depressive disorder
Major depressive disorder best fits because she has at least five depressive symptoms, including either depressed mood or loss of interest, present nearly every day for more than two weeks and causing impairment, which is the diagnostic threshold for a major depressive episode. Bipolar I disorder requires a current or prior manic episode, which she explicitly denies. Generalized anxiety disorder centers on excessive worry rather than pervasive sadness and anhedonia, and adjustment disorder requires an identifiable stressor and does not meet full criteria for a major depressive episode.
- A primary care physician wants to use a brief, validated, self-administered instrument to both screen for depression and quantify symptom severity in adult patients during routine visits. Which tool is most appropriate for this purpose?
- CHA2DS2-VASc score
- Mini-Mental State Examination
- CURB-65 score
- Patient Health Questionnaire-9 (PHQ-9)
Correct answer: Patient Health Questionnaire-9 (PHQ-9)
The Patient Health Questionnaire-9 is most appropriate because it is a nine-item self-report measure mapped directly to the diagnostic criteria for depression, allowing clinicians to screen for the disorder and grade severity from mild to severe, and to track response to treatment over time. The CHA2DS2-VASc score estimates stroke risk in atrial fibrillation, the Mini-Mental State Examination screens for cognitive impairment rather than mood, and the CURB-65 score assesses pneumonia severity, none of which measure depressive symptoms.
- A 45-year-old man is diagnosed with moderate major depressive disorder and has no prior psychiatric history. He prefers medication over psychotherapy alone. Which class of antidepressant is most appropriate to start first?
- Monoamine oxidase inhibitor
- Tricyclic antidepressant
- Selective serotonin reuptake inhibitor
- Typical (first-generation) antipsychotic
Correct answer: Selective serotonin reuptake inhibitor
A selective serotonin reuptake inhibitor is the most appropriate first-line choice because agents such as sertraline or escitalopram have a favorable side-effect and safety profile, are well tolerated, and are recommended as initial pharmacotherapy for major depressive disorder. Monoamine oxidase inhibitors carry dietary and drug-interaction risks and tricyclic antidepressants are dangerous in overdose, so both are reserved for later use, and typical antipsychotics treat psychosis rather than uncomplicated depression.
- A patient with major depressive disorder began an adequate dose of a selective serotonin reuptake inhibitor. After how long of an adequate trial is it generally reasonable to judge whether the medication is effective before considering a change in therapy?
- After 4 to 6 weeks
- Within 48 hours
- After 6 months
- After 12 months
Correct answer: After 4 to 6 weeks
Judging effectiveness after 4 to 6 weeks at an adequate dose is correct because antidepressants typically require several weeks before a full therapeutic response emerges, and a trial of this length is needed before concluding a medication has failed and switching or augmenting. Expecting improvement within 48 hours is unrealistic given the delayed onset of these drugs, while waiting 6 to 12 months before reassessing would needlessly prolong ineffective treatment and patient suffering.
- An internist evaluates a patient with newly diagnosed depression. Before attributing the symptoms entirely to a primary mood disorder, which laboratory abnormality is most important to exclude because it commonly mimics or contributes to depressive symptoms?
- Hyperkalemia
- Hypothyroidism
- Iron deficiency without anemia
- Mild hyperbilirubinemia
Correct answer: Hypothyroidism
Hypothyroidism is the most important to exclude because low thyroid hormone frequently produces fatigue, low mood, poor concentration, and psychomotor slowing that closely mimic a major depressive episode, and checking thyroid-stimulating hormone is part of the basic workup of new depression. Hyperkalemia, iron deficiency without anemia, and mild hyperbilirubinemia are not characteristically associated with a depressive syndrome and would not explain the mood disturbance.
- A 28-year-old man is brought in by family who report that for the past week he has slept only two hours a night yet feels energetic, has been talking rapidly, started several grandiose business ventures, and spent thousands of dollars impulsively. He had a major depressive episode two years ago. Which diagnosis best explains his current presentation?
- Persistent depressive disorder (dysthymia)
- Generalized anxiety disorder
- Bipolar I disorder
- Major depressive disorder, severe
Correct answer: Bipolar I disorder
Bipolar I disorder best explains this presentation because a distinct period of elevated mood with decreased need for sleep, pressured speech, grandiosity, and excessive involvement in high-risk activities lasting about a week meets criteria for a manic episode, which defines bipolar I, especially with his prior depressive episode. Persistent depressive disorder describes chronic low-grade depression, generalized anxiety disorder centers on worry, and a severe major depressive episode would not include the elevated, expansive, hyperactive features seen here.
- A 50-year-old man with longstanding alcohol use disorder is admitted after stopping drinking abruptly two days ago. He is now tremulous, diaphoretic, tachycardic, hypertensive, agitated, and disoriented, and he reports seeing insects on the wall. Which complication of alcohol withdrawal is most consistent with this picture?
- Wernicke encephalopathy
- Delirium tremens
- Hepatic encephalopathy
- Isolated withdrawal tremor
Correct answer: Delirium tremens
Delirium tremens is most consistent because the combination of autonomic hyperactivity, marked agitation, disorientation, and hallucinations developing roughly two to four days after the last drink represents the most severe form of alcohol withdrawal and is a medical emergency. Wernicke encephalopathy features the triad of confusion, ophthalmoplegia, and ataxia from thiamine deficiency rather than florid autonomic instability, hepatic encephalopathy produces asterixis and elevated ammonia without this hyperadrenergic state, and an isolated withdrawal tremor lacks the confusion and hallucinations seen here.
- Which class of medications is the cornerstone of pharmacologic treatment for moderate-to-severe alcohol withdrawal to prevent progression to seizures and delirium tremens?
- Selective serotonin reuptake inhibitors
- Beta-blockers
- Typical antipsychotics
- Benzodiazepines
Correct answer: Benzodiazepines
Benzodiazepines are the cornerstone because they enhance GABA-mediated inhibition that is deficient during alcohol withdrawal, reducing autonomic hyperactivity and preventing withdrawal seizures and delirium tremens, often guided by a symptom-triggered protocol. Selective serotonin reuptake inhibitors treat depression and have no role in acute withdrawal, beta-blockers may blunt tachycardia but do not prevent seizures or delirium and can mask worsening, and typical antipsychotics lower the seizure threshold and are not first-line therapy.
- A validated symptom-based scoring tool is used at the bedside to quantify the severity of alcohol withdrawal and to drive symptom-triggered benzodiazepine dosing. Which instrument serves this purpose?
- Glasgow Coma Scale
- CIWA-Ar (Clinical Institute Withdrawal Assessment for Alcohol)
- Wells score
- MELD score
Correct answer: CIWA-Ar (Clinical Institute Withdrawal Assessment for Alcohol)
The CIWA-Ar is the correct instrument because it scores withdrawal features such as tremor, sweating, anxiety, agitation, and hallucinations to grade severity and to guide symptom-triggered benzodiazepine administration, individualizing therapy and reducing total medication exposure. The Glasgow Coma Scale rates level of consciousness in trauma, the Wells score estimates pulmonary embolism probability, and the MELD score predicts mortality in liver disease, none of which assess alcohol withdrawal severity.
- A malnourished patient with chronic alcohol use is admitted with withdrawal and will receive intravenous fluids containing dextrose. To prevent precipitating Wernicke encephalopathy, which intervention should be given before or with the glucose?
- Folate
- Vitamin C
- Vitamin K
- Thiamine
Correct answer: Thiamine
Thiamine should be given because administering glucose to a thiamine-deficient patient can deplete remaining thiamine and precipitate Wernicke encephalopathy, so thiamine is repleted before or alongside dextrose-containing fluids. Folate corrects megaloblastic anemia but does not prevent Wernicke encephalopathy, vitamin C addresses scurvy, and vitamin K corrects coagulopathy from impaired clotting factor synthesis, none of which guard against the acute neurologic injury of thiamine deficiency.
- A 40-year-old woman reports six months of excessive, hard-to-control worry about many areas of her life, accompanied by restlessness, muscle tension, fatigue, irritability, and difficulty sleeping. A medical workup is unremarkable. Which diagnosis best fits?
- Panic disorder
- Generalized anxiety disorder
- Social anxiety disorder
- Major depressive disorder
Correct answer: Generalized anxiety disorder
Generalized anxiety disorder best fits because persistent, excessive, and difficult-to-control worry about multiple domains for at least six months, with associated symptoms such as restlessness, muscle tension, fatigue, irritability, and sleep disturbance, defines the condition. Panic disorder is characterized by recurrent discrete panic attacks rather than chronic diffuse worry, social anxiety disorder involves fear specifically of social or performance situations, and major depressive disorder centers on pervasive sadness and anhedonia rather than dominant worry.
- A 30-year-old man presents to the emergency department convinced he is having a heart attack. He describes recurrent, abrupt episodes of pounding heart, chest tightness, shortness of breath, dizziness, sweating, and a fear of dying that peak within minutes and resolve spontaneously. Cardiac and metabolic evaluations are repeatedly normal. He now avoids leaving home for fear of another attack. Which condition best explains this presentation?
- Acute coronary syndrome
- Hyperthyroidism
- Generalized anxiety disorder
- Panic disorder
Correct answer: Panic disorder
Panic disorder best explains this presentation because recurrent unexpected panic attacks with abrupt surges of physical and cognitive symptoms peaking within minutes, followed by persistent worry about further attacks and avoidance behavior, are its defining features once medical causes are excluded. Acute coronary syndrome and hyperthyroidism were ruled out by repeatedly normal cardiac and metabolic testing, and generalized anxiety disorder produces sustained worry rather than these discrete, self-limited attacks.
- A 32-year-old combat veteran reports that for several months since returning from deployment he has had intrusive nightmares and flashbacks of a roadside explosion, avoids reminders of the event, feels emotionally numb and hypervigilant, and startles easily. Which diagnosis best accounts for these symptoms?
- Generalized anxiety disorder
- Major depressive disorder
- Post-traumatic stress disorder
- Adjustment disorder
Correct answer: Post-traumatic stress disorder
Post-traumatic stress disorder best accounts for these symptoms because exposure to a life-threatening traumatic event followed by intrusive re-experiencing, avoidance of trauma reminders, negative alterations in mood and cognition, and hyperarousal persisting beyond one month defines the disorder. Generalized anxiety disorder lacks a defining trauma and re-experiencing symptoms, major depressive disorder centers on mood rather than trauma-linked intrusions, and adjustment disorder does not involve exposure to a qualifying traumatic event with the full re-experiencing and hyperarousal cluster.
- A 24-year-old woman is brought in after expressing thoughts of ending her life. Which feature most strongly increases her immediate risk and warrants urgent intervention such as hospitalization?
- Vague wish that she were not alive, without intent
- A specific suicide plan with access to lethal means and stated intent
- Past history of depression now in remission
- Recently started psychotherapy
Correct answer: A specific suicide plan with access to lethal means and stated intent
A specific plan with access to lethal means and stated intent most strongly raises immediate risk because the combination of intent, a concrete method, and the ability to carry it out signals high acute danger and typically warrants urgent measures such as constant observation or hospitalization. A passive wish to be dead without intent is concerning but lower acuity, a remote history of depression in remission is a background factor rather than an acute driver, and engagement in psychotherapy reflects protective help-seeking rather than elevated immediate risk.
- A 35-year-old woman repeatedly presents with multiple distressing physical complaints across different organ systems. Extensive evaluations are unrevealing, yet she remains excessively preoccupied with her symptoms, devotes disproportionate time and anxiety to her health, and is not reassured. Which diagnosis best characterizes her presentation?
- Factitious disorder
- Malingering
- Somatic symptom disorder
- Generalized anxiety disorder
Correct answer: Somatic symptom disorder
Somatic symptom disorder best characterizes this presentation because it is defined by one or more distressing somatic symptoms accompanied by excessive thoughts, feelings, and behaviors devoted to those symptoms and persistent disproportionate health anxiety, regardless of whether a medical explanation is found. Factitious disorder involves intentional falsification of illness to assume the sick role, malingering involves feigning symptoms for external gain such as money or avoiding work, and generalized anxiety disorder centers on broad worry rather than a dominant focus on bodily symptoms.
- A 19-year-old woman is significantly underweight, intensely fears gaining weight, severely restricts her food intake, and perceives herself as overweight despite being markedly thin. She has amenorrhea and bradycardia. Which diagnosis best fits, and what is the most serious immediate concern during refeeding?
- Anorexia nervosa; refeeding syndrome with hypophosphatemia
- Bulimia nervosa; esophageal rupture
- Binge eating disorder; obesity-related complications
- Major depressive disorder; serotonin syndrome
Correct answer: Anorexia nervosa; refeeding syndrome with hypophosphatemia
Anorexia nervosa with refeeding syndrome is correct because restriction of intake leading to significantly low body weight, intense fear of weight gain, and distorted body image define anorexia nervosa, and reintroducing nutrition can trigger dangerous intracellular shifts, most notably hypophosphatemia, causing cardiac and neuromuscular complications. Bulimia nervosa involves binge-purge cycles usually at normal weight, binge eating disorder lacks compensatory restriction and underweight, and major depressive disorder does not explain the weight phobia and body image distortion central to this presentation.
- A 26-year-old man with depression treated with a selective serotonin reuptake inhibitor recently added a second serotonergic medication. He now presents with agitation, fever, diaphoresis, tremor, hyperreflexia, and clonus that is more pronounced in the lower extremities. Which condition is most likely?
- Neuroleptic malignant syndrome
- Serotonin syndrome
- Malignant hyperthermia
- Anticholinergic toxicity
Correct answer: Serotonin syndrome
Serotonin syndrome is most likely because the triad of mental status change, autonomic instability, and neuromuscular hyperactivity, with hyperreflexia and clonus predominating in the lower limbs, arises from excess serotonergic activity after combining serotonergic agents. Neuroleptic malignant syndrome follows dopamine-blocking agents and produces rigidity with hyporeflexia and bradykinesia rather than clonus, malignant hyperthermia is triggered by anesthetic agents, and anticholinergic toxicity causes dry skin and absent bowel sounds without the clonus and hyperreflexia seen here.
- A 60-year-old man with schizophrenia treated with a high-potency antipsychotic develops over several days high fever, severe muscle rigidity, altered mental status, autonomic instability, and a markedly elevated creatine kinase level. Which diagnosis is most consistent with this picture?
- Serotonin syndrome
- Acute dystonic reaction
- Tardive dyskinesia
- Neuroleptic malignant syndrome
Correct answer: Neuroleptic malignant syndrome
Neuroleptic malignant syndrome is most consistent because hyperthermia, lead-pipe muscular rigidity, altered consciousness, autonomic dysfunction, and a sharply elevated creatine kinase developing after exposure to dopamine-blocking antipsychotics are its hallmark features. Serotonin syndrome typically develops more rapidly with clonus and hyperreflexia rather than rigidity, an acute dystonic reaction causes sustained focal muscle spasms without fever or elevated creatine kinase, and tardive dyskinesia is a late-onset involuntary movement disorder lacking fever, rigidity, and autonomic instability.
- A 22-year-old man is brought in by his parents because over the past eight months he has become withdrawn, expresses bizarre beliefs that strangers are broadcasting his thoughts, hears voices commenting on his actions, and shows disorganized speech, with functional decline at school. There is no evidence of substance use or a mood episode. Which diagnosis best fits?
- Schizophrenia
- Brief psychotic disorder
- Bipolar I disorder with psychotic features
- Major depressive disorder with psychotic features
Correct answer: Schizophrenia
Schizophrenia best fits because continuous signs of illness for at least six months that include delusions, auditory hallucinations, and disorganized speech with marked functional decline, in the absence of a primary mood episode or substance cause, meet its diagnostic criteria. Brief psychotic disorder lasts less than one month, bipolar I and major depressive disorder with psychotic features require a defining manic or depressive episode that is absent here, so the persistent primary psychotic syndrome is best classified as schizophrenia.
- A 64-year-old man with a 40-pack-year smoking history reports chronic productive cough and progressive dyspnea. Post-bronchodilator spirometry shows an FEV1/FVC ratio of 0.62. Which finding is required to confirm a diagnosis of COPD?
- A persistent post-bronchodilator FEV1/FVC ratio below 0.70
- A total lung capacity below the lower limit of normal
- An elevated diffusing capacity for carbon monoxide
- Complete normalization of the FEV1 after bronchodilator
Correct answer: A persistent post-bronchodilator FEV1/FVC ratio below 0.70
A persistent post-bronchodilator FEV1/FVC ratio below 0.70 is the spirometric criterion that confirms COPD, demonstrating the fixed airflow limitation that defines the disease. A reduced total lung capacity indicates a restrictive pattern, not COPD; the diffusing capacity is typically reduced in emphysema rather than elevated; and full normalization of FEV1 after bronchodilator points toward asthma instead.
- A patient with COPD whose post-bronchodilator FEV1 is 45% of predicted asks how their disease is staged. Using the GOLD spirometric classification, this FEV1 corresponds to which grade of airflow limitation?
- GOLD 1 (mild)
- GOLD 3 (severe)
- GOLD 2 (moderate)
- GOLD 4 (very severe)
Correct answer: GOLD 3 (severe)
An FEV1 of 45% predicted falls into GOLD 3 (severe), because the GOLD grades define severe airflow limitation as an FEV1 between 30% and 49% of predicted. GOLD 1 requires an FEV1 of at least 80%, GOLD 2 spans 50% to 79%, and GOLD 4 (very severe) is reserved for an FEV1 below 30%.
- A 70-year-old with COPD presents with acutely increased dyspnea, increased sputum volume, and new sputum purulence. Vital signs are stable and oxygen saturation is 90% on room air. Besides a short-acting bronchodilator and supplemental oxygen, which intervention is most appropriate for this exacerbation?
- Long-term azithromycin started today for prophylaxis
- Immediate intubation and mechanical ventilation
- A 5-day course of oral corticosteroids plus an antibiotic
- A loop diuretic to reduce airway edema
Correct answer: A 5-day course of oral corticosteroids plus an antibiotic
A short course of oral corticosteroids combined with an antibiotic is appropriate, because this patient has all three cardinal features of an exacerbation (increased dyspnea, sputum volume, and purulence), and the presence of purulence supports antibiotic use. Chronic prophylactic azithromycin is a maintenance strategy, not acute therapy; this stable patient does not need intubation; and diuretics treat pulmonary edema, not COPD exacerbation.
- A 68-year-old man with severe COPD has resting hypoxemia with a PaO2 of 52 mmHg measured on room air on two occasions. Which intervention has been shown to improve survival in this setting?
- An inhaled corticosteroid monotherapy
- A daily oral theophylline regimen
- Scheduled morphine for dyspnea relief
- Long-term continuous supplemental oxygen therapy
Correct answer: Long-term continuous supplemental oxygen therapy
Long-term continuous supplemental oxygen improves survival in COPD patients with chronic severe resting hypoxemia (PaO2 at or below 55 mmHg, or at or below 59 mmHg with cor pulmonale or polycythemia). Inhaled corticosteroids and theophylline relieve symptoms or reduce exacerbations but do not extend survival in this scenario, and opioids palliate refractory dyspnea without affecting mortality.
- A nonsmoking 42-year-old develops early-onset panlobular emphysema predominantly at the lung bases and has abnormal liver tests. Which underlying diagnosis should be evaluated?
- Alpha-1 antitrypsin deficiency
- Cystic fibrosis
- Idiopathic pulmonary fibrosis
- Hypersensitivity pneumonitis
Correct answer: Alpha-1 antitrypsin deficiency
Alpha-1 antitrypsin deficiency should be evaluated, because early-onset basilar-predominant panlobular emphysema in a nonsmoker accompanied by liver disease is the classic presentation of this inherited deficiency. Cystic fibrosis produces bronchiectasis and recurrent infection; idiopathic pulmonary fibrosis causes restriction, not emphysema; and hypersensitivity pneumonitis follows antigen exposure with an inflammatory pattern.
- A 66-year-old woman with COPD on a long-acting muscarinic antagonist still has frequent symptoms and two exacerbations in the past year. Her blood eosinophil count is elevated. Which adjustment to her inhaler regimen is best supported?
- Switch entirely to an as-needed short-acting agent
- Add a long-acting beta-agonist and an inhaled corticosteroid
- Discontinue all inhalers and rely on oral steroids
- Begin chronic systemic corticosteroids indefinitely
Correct answer: Add a long-acting beta-agonist and an inhaled corticosteroid
Adding a long-acting beta-agonist and an inhaled corticosteroid is best, because frequent exacerbations with an elevated blood eosinophil count predict benefit from inhaled corticosteroid escalation alongside dual bronchodilation. Reverting to as-needed short-acting therapy undertreats her; abandoning inhalers worsens control; and chronic systemic steroids carry unacceptable long-term toxicity in COPD.
- During an acute COPD exacerbation, a patient is hypercapnic with a pH of 7.28 and remains alert. Which intervention most reduces the need for intubation and improves outcomes in this hypercapnic respiratory failure?
- High-flow 100% oxygen by nonrebreather mask
- Intravenous sodium bicarbonate infusion
- Noninvasive positive-pressure ventilation
- Empiric inhaled nitric oxide
Correct answer: Noninvasive positive-pressure ventilation
Noninvasive positive-pressure ventilation reduces intubation rates and mortality in COPD exacerbations complicated by acute hypercapnic acidosis when the patient is alert and protecting the airway. Administering high concentrations of oxygen can worsen hypercapnia; bicarbonate does not address the respiratory cause of the acidosis; and inhaled nitric oxide has no established role here.
- A clinician counsels a 58-year-old patient with moderate COPD who continues to smoke. Which single intervention has the greatest impact on slowing the long-term decline in lung function?
- Daily inhaled corticosteroid use
- Routine annual chest CT scanning
- A high-protein dietary supplement
- Complete smoking cessation
Correct answer: Complete smoking cessation
Complete smoking cessation has the greatest effect on slowing the accelerated decline in FEV1 over time and is the only intervention proven to alter the natural history of COPD. Inhaled corticosteroids modify symptoms and exacerbations but not the rate of lung-function decline, while CT screening and nutritional supplements do not change disease progression.
- A 55-year-old woman with no prior lung disease presents with sudden pleuritic chest pain, dyspnea, and tachycardia three days after knee replacement surgery. The clinician calculates a Wells score that places her in a high pretest probability category for pulmonary embolism. What is the most appropriate next diagnostic step?
- Proceed directly to CT pulmonary angiography
- Order a D-dimer and stop if it is negative
- Obtain a transthoracic echocardiogram first
- Discharge with outpatient follow-up in one week
Correct answer: Proceed directly to CT pulmonary angiography
Proceeding directly to CT pulmonary angiography is correct, because in a patient with high pretest probability for pulmonary embolism a D-dimer cannot reliably exclude disease and imaging should be pursued immediately. Relying on a D-dimer to rule out PE is appropriate only at low or intermediate probability; echocardiography assesses right heart strain but does not confirm the diagnosis; and deferring evaluation risks a fatal event.
- A 47-year-old man with calf swelling and mild dyspnea has a low pretest probability for pulmonary embolism by Wells criteria. Which result would allow the clinician to safely exclude pulmonary embolism without imaging?
- A normal resting electrocardiogram
- A negative high-sensitivity D-dimer
- A normal room-air oxygen saturation
- A normal chest radiograph
Correct answer: A negative high-sensitivity D-dimer
A negative high-sensitivity D-dimer safely excludes pulmonary embolism in a patient with low pretest probability, combining clinical assessment with a sensitive laboratory test. A normal electrocardiogram, normal oxygen saturation, and normal chest radiograph are each common in PE and cannot rule it out, since many patients with PE have unremarkable findings on these tests.
- A 60-year-old woman is diagnosed with an acute pulmonary embolism. She is hemodynamically stable with normal blood pressure, no right ventricular dysfunction, and normal cardiac biomarkers. Which treatment approach is most appropriate?
- Systemic thrombolytic therapy
- Surgical pulmonary embolectomy
- Therapeutic anticoagulation alone
- An inferior vena cava filter as primary therapy
Correct answer: Therapeutic anticoagulation alone
Therapeutic anticoagulation alone is appropriate, because a hemodynamically stable patient without right ventricular strain or biomarker elevation has a low-risk PE that does not require clot-dissolving therapy. Systemic thrombolysis is reserved for massive PE with hemodynamic instability; embolectomy is a salvage option; and an IVC filter is used mainly when anticoagulation is contraindicated.
- A 70-year-old man presents with acute pulmonary embolism complicated by persistent hypotension and signs of shock despite fluids. There are no contraindications to fibrinolysis. Which intervention is most appropriate?
- A 5-day course of low-dose aspirin
- Observation with serial troponins
- An inhaled bronchodilator regimen
- Systemic thrombolytic therapy
Correct answer: Systemic thrombolytic therapy
Systemic thrombolytic therapy is indicated for this massive (high-risk) pulmonary embolism with sustained hypotension and shock, because dissolving the clot rapidly reduces mortality when there is no bleeding contraindication. Aspirin is inadequate for acute PE; mere observation is dangerous in a patient in shock; and bronchodilators do not treat thromboembolic obstruction.
- A 36-year-old pregnant woman in her second trimester is suspected of having a pulmonary embolism. Which feature of the standard diagnostic algorithm requires modification in pregnancy?
- D-dimer thresholds are less reliable because levels rise physiologically in pregnancy
- Anticoagulation should never be started until after delivery
- CT and ventilation-perfusion imaging are absolutely contraindicated
- Wells scoring cannot be applied to pregnant patients at all
Correct answer: D-dimer thresholds are less reliable because levels rise physiologically in pregnancy
D-dimer interpretation is less reliable in pregnancy because D-dimer rises physiologically across gestation, reducing its usefulness for excluding PE. Anticoagulation with low-molecular-weight heparin is in fact the treatment of choice during pregnancy; imaging such as CT pulmonary angiography or ventilation-perfusion scanning can be performed with attention to radiation; and clinical probability assessment still informs the workup.
- A patient is started on anticoagulation for a first unprovoked pulmonary embolism. For most such patients without high bleeding risk, what is the recommended minimum duration of anticoagulation before reassessing the need for extended therapy?
- About 1 week
- At least 3 months
- Exactly 14 days
- Lifelong with no reassessment
Correct answer: At least 3 months
A minimum of 3 months of anticoagulation is recommended for an acute pulmonary embolism, after which the clinician reassesses whether to extend therapy based on recurrence and bleeding risk. One week or two weeks is far too short to prevent recurrence, and committing to lifelong therapy without reassessing the risk-benefit balance is not the standard initial approach.
- A previously healthy 50-year-old man develops a large pulmonary embolism. Which physiologic abnormality on arterial blood gas analysis is most characteristic early in acute pulmonary embolism?
- Hypercapnia with respiratory acidosis
- Metabolic alkalosis with a low chloride
- Hypoxemia with respiratory alkalosis from hyperventilation
- A normal alveolar-arterial oxygen gradient
Correct answer: Hypoxemia with respiratory alkalosis from hyperventilation
Hypoxemia accompanied by respiratory alkalosis is characteristic, because acute PE causes ventilation-perfusion mismatch leading to low oxygen while tachypnea drives off carbon dioxide. Hypercapnia is uncommon early unless the patient tires; metabolic alkalosis is unrelated; and the alveolar-arterial oxygen gradient is typically widened rather than normal.
- Six months after an acute pulmonary embolism, a 62-year-old woman has persistent exertional dyspnea, and echocardiography shows pulmonary hypertension. A ventilation-perfusion scan reveals multiple unmatched perfusion defects. Which diagnosis does this picture suggest?
- Recurrent community-acquired pneumonia
- New-onset asthma
- Pulmonary alveolar proteinosis
- Chronic thromboembolic pulmonary hypertension
Correct answer: Chronic thromboembolic pulmonary hypertension
Chronic thromboembolic pulmonary hypertension is suggested, because persistent perfusion defects on ventilation-perfusion scanning with pulmonary hypertension months after a PE indicate unresolved organized thrombus. Recurrent pneumonia would show infiltrates and infection; asthma causes reversible airflow obstruction; and alveolar proteinosis has a distinct crazy-paving radiographic pattern.
- A 22-year-old with intermittent asthma uses an albuterol inhaler only during occasional symptoms, averaging once weekly with normal lung function between episodes. According to current step-care recommendations, which controller strategy is most appropriate?
- As-needed low-dose inhaled corticosteroid-formoterol
- A scheduled high-dose inhaled corticosteroid daily
- Chronic daily oral corticosteroids
- A long-acting beta-agonist used as monotherapy
Correct answer: As-needed low-dose inhaled corticosteroid-formoterol
As-needed low-dose inhaled corticosteroid-formoterol is preferred even in mild asthma, because combining an anti-inflammatory steroid with reliever therapy reduces severe exacerbations compared with short-acting bronchodilator alone. High-dose daily steroids are excessive for mild disease, chronic oral steroids are inappropriate, and a long-acting beta-agonist used alone is unsafe in asthma.
- A 30-year-old woman with asthma reports daily symptoms and frequent nighttime awakenings despite using a low-dose inhaled corticosteroid. What is the most appropriate next step in her controller therapy?
- Stop the inhaled corticosteroid and use albuterol only
- Add a long-acting beta-agonist to her inhaled corticosteroid
- Begin a long-acting muscarinic antagonist as the sole controller
- Switch to a daily leukotriene receptor antagonist alone
Correct answer: Add a long-acting beta-agonist to her inhaled corticosteroid
Adding a long-acting beta-agonist to the inhaled corticosteroid is the recommended step-up, because combination inhaled corticosteroid plus long-acting beta-agonist improves control when low-dose steroid alone is insufficient. Stopping the steroid removes essential anti-inflammatory therapy, a long-acting muscarinic antagonist alone is not first-line, and switching to a leukotriene agent alone is generally less effective than combination therapy.
- A 19-year-old presents to the emergency department with a severe asthma exacerbation, marked wheezing, and accessory muscle use. After oxygen, which two therapies form the immediate cornerstone of acute management?
- Inhaled long-acting beta-agonist monotherapy
- Intravenous antibiotics plus a mucolytic
- Inhaled short-acting beta-agonist plus systemic corticosteroids
- A leukotriene antagonist plus an antihistamine
Correct answer: Inhaled short-acting beta-agonist plus systemic corticosteroids
Repeated inhaled short-acting beta-agonist combined with systemic corticosteroids is the cornerstone of an acute asthma exacerbation, providing rapid bronchodilation plus anti-inflammatory effect to shorten the attack. Long-acting beta-agonist alone is not used for acute rescue; antibiotics are not routine without infection; and leukotriene antagonists with antihistamines do not control an acute attack.
- A patient in status asthmaticus is tiring, and an arterial blood gas now shows a normal PaCO2 of 40 mmHg after prior hypocapnia. How should this finding be interpreted?
- Reassuring evidence that the attack is resolving
- An indication to stop bronchodilator therapy
- Proof that the diagnosis is not asthma
- A warning sign of impending respiratory failure
Correct answer: A warning sign of impending respiratory failure
A normalizing or rising PaCO2 during a severe asthma attack is an ominous warning of impending respiratory failure, because a patient with severe airflow obstruction should be hyperventilating with low carbon dioxide; a normal value signals fatigue. It is not reassuring, does not justify stopping treatment, and does not refute the asthma diagnosis.
- A 25-year-old athlete reports cough, chest tightness, and wheezing that occur only several minutes into vigorous exercise and resolve with rest. Which therapy is most appropriate to prevent these episodes?
- An inhaled short-acting beta-agonist used before exercise
- A daily oral corticosteroid taper
- Long-term oxygen therapy
- Chronic broad-spectrum antibiotics
Correct answer: An inhaled short-acting beta-agonist used before exercise
An inhaled short-acting beta-agonist taken shortly before exercise is the standard preventive treatment for exercise-induced bronchoconstriction, blocking the airway narrowing triggered by exertion. Oral corticosteroid tapers are not indicated for this intermittent trigger, long-term oxygen is unnecessary, and antibiotics have no role in this noninfectious airway response.
- A 40-year-old woman with poorly controlled asthma is found to have aspirin sensitivity and recurrent nasal polyps. Exposure to which class of medications is most likely to precipitate an acute asthma attack in this patient?
- Inhaled corticosteroids
- Nonsteroidal anti-inflammatory drugs
- Leukotriene receptor antagonists
- Long-acting muscarinic antagonists
Correct answer: Nonsteroidal anti-inflammatory drugs
Nonsteroidal anti-inflammatory drugs are most likely to trigger an attack, because this aspirin-exacerbated respiratory disease involves cyclooxygenase inhibition that shunts arachidonic acid toward bronchoconstricting leukotrienes. Inhaled corticosteroids and leukotriene antagonists actually treat the disease, and long-acting muscarinic antagonists do not provoke this reaction.
- A 35-year-old with persistent asthma whose symptoms worsen at home but improve on vacation has high serum IgE and positive skin testing to dust mites. Beyond controller medications, which intervention directly targets the cause of his symptoms?
- Increasing his short-acting beta-agonist frequency
- Starting a long-term macrolide antibiotic
- Environmental allergen avoidance measures
- Adding a daily mucolytic agent
Correct answer: Environmental allergen avoidance measures
Environmental allergen avoidance directly addresses the trigger, because allergic asthma driven by demonstrated dust-mite sensitization improves when exposure to the offending allergen is reduced. Escalating short-acting beta-agonist use treats symptoms without addressing the cause, and neither chronic macrolides nor mucolytics target the underlying allergic mechanism.
- A 50-year-old man has severe eosinophilic asthma with frequent exacerbations despite high-dose inhaled corticosteroid plus long-acting beta-agonist therapy and a markedly elevated blood eosinophil count. Which add-on therapy is most appropriate?
- A daily inhaled short-acting beta-agonist schedule
- An oral decongestant
- A long-term inhaled antibiotic
- An anti-interleukin-5 biologic agent
Correct answer: An anti-interleukin-5 biologic agent
An anti-interleukin-5 biologic is most appropriate, because severe eosinophilic asthma with high blood eosinophils and frequent exacerbations responds to therapies that target the interleukin-5 eosinophil pathway. Scheduled short-acting beta-agonist, decongestants, and inhaled antibiotics do not address the type 2 eosinophilic inflammation driving this phenotype.
- A 65-year-old man with dyspnea has decreased breath sounds and dullness to percussion at the right lung base. A pleural effusion is confirmed and thoracentesis is performed. The Light criteria are used to classify the fluid. Which finding indicates that the effusion is an exudate?
- A pleural-fluid to serum protein ratio greater than 0.5
- A pleural-fluid pH above 7.6
- A pleural-fluid glucose equal to serum glucose
- A clear, straw-colored appearance
Correct answer: A pleural-fluid to serum protein ratio greater than 0.5
A pleural-fluid to serum protein ratio greater than 0.5 meets a Light criterion for an exudate, reflecting increased capillary permeability or impaired lymphatic drainage. Pleural-fluid pH, glucose comparable to serum, and clear appearance do not by themselves define an exudate; the Light criteria rely on protein and lactate dehydrogenase ratios.
- A patient with longstanding heart failure develops bilateral pleural effusions. Thoracentesis yields fluid that does not meet any Light criteria for an exudate. Which underlying mechanism best explains this transudative effusion?
- Malignant pleural infiltration
- Elevated hydrostatic pressure in the pulmonary circulation
- Bacterial infection of the pleural space
- Lymphatic obstruction by tumor
Correct answer: Elevated hydrostatic pressure in the pulmonary circulation
Elevated hydrostatic pressure from heart failure drives a transudative effusion, in which fluid filters across intact pleural membranes without the high protein content seen in exudates. Malignant infiltration, pleural-space infection, and lymphatic obstruction by tumor each cause exudative effusions through inflammation or increased permeability.
- A 58-year-old man with community-acquired pneumonia develops a pleural effusion. Thoracentesis reveals frank pus with a pleural-fluid pH of 7.05 and a very low glucose. Beyond antibiotics, what is the most appropriate management?
- Observation with repeat imaging in two weeks
- A single therapeutic thoracentesis and discharge
- Chest tube drainage of the pleural space
- Oral diuretics to resorb the fluid
Correct answer: Chest tube drainage of the pleural space
Chest tube drainage is required, because an empyema or complicated parapneumonic effusion with frank pus, a low pH, and low glucose will not resolve with antibiotics alone and needs source control. Observation risks loculation and sepsis, a single thoracentesis is inadequate for an infected collection, and diuretics do not clear an infected pleural space.
- A patient undergoes thoracentesis, and the pleural fluid is milky white. Analysis shows a high triglyceride level and the presence of chylomicrons. Which diagnosis does this indicate?
- Empyema from anaerobic infection
- Hemothorax from chest trauma
- A simple transudative effusion
- Chylothorax from thoracic duct disruption
Correct answer: Chylothorax from thoracic duct disruption
A milky effusion rich in triglycerides and chylomicrons indicates a chylothorax caused by leakage of lymph from the thoracic duct, often due to malignancy or surgical injury. Empyema yields purulent fluid, a hemothorax is bloody with a high hematocrit, and a simple transudate is clear with low protein and lipid content.
- A 67-year-old former smoker with a unilateral pleural effusion has cytology and fluid analysis suggesting malignancy, and he has recurrent symptomatic reaccumulation after repeated thoracentesis. Which intervention provides durable palliation?
- Pleurodesis or an indwelling pleural catheter
- Long-term oral corticosteroids
- A short course of inhaled bronchodilators
- Empiric antifungal therapy
Correct answer: Pleurodesis or an indwelling pleural catheter
Pleurodesis or an indwelling pleural catheter provides durable palliation of a recurrent malignant pleural effusion by obliterating the pleural space or allowing ongoing drainage. Oral corticosteroids, inhaled bronchodilators, and antifungal agents do not control the reaccumulation of malignant fluid.
- A clinician evaluates a small unilateral pleural effusion of unknown cause. The first diagnostic thoracentesis fluid analysis would most help distinguish between which two broad categories of effusion?
- Acute versus chronic infection
- Transudate versus exudate
- Arterial versus venous bleeding
- Restrictive versus obstructive disease
Correct answer: Transudate versus exudate
The initial fluid analysis primarily distinguishes a transudate from an exudate, which directs the subsequent workup toward systemic causes such as heart failure versus local pleural processes such as infection or malignancy. It does not chiefly separate acute from chronic infection, classify bleeding sources, or define ventilatory mechanics.
- A 52-year-old obese man reports loud snoring, witnessed apneas, and daytime sleepiness. Which test is the gold standard for confirming a diagnosis of obstructive sleep apnea?
- A daytime arterial blood gas
- A standard chest radiograph
- Attended in-laboratory polysomnography
- Spirometry with bronchodilator response
Correct answer: Attended in-laboratory polysomnography
Attended in-laboratory polysomnography is the gold standard for diagnosing obstructive sleep apnea, quantifying apneas and hypopneas per hour of sleep. A daytime blood gas, chest radiograph, and spirometry assess other aspects of respiratory function and cannot establish the diagnosis of sleep-disordered breathing.
- A 48-year-old woman is diagnosed with moderate-to-severe obstructive sleep apnea. Which therapy is considered first-line and most effective for reducing apneic events and daytime symptoms?
- A bedtime sedative-hypnotic
- Supplemental nighttime oxygen alone
- A daily inhaled corticosteroid
- Continuous positive airway pressure
Correct answer: Continuous positive airway pressure
Continuous positive airway pressure is the first-line and most effective therapy, because the delivered positive pressure splints the upper airway open and abolishes obstructive events. Sedative-hypnotics can worsen apnea, supplemental oxygen alone does not prevent airway collapse, and inhaled corticosteroids treat airway inflammation rather than mechanical obstruction.
- A patient with untreated severe obstructive sleep apnea is at increased risk of developing which long-term cardiovascular complication?
- Resistant systemic hypertension
- Aortic valve stenosis
- Hypertrophic cardiomyopathy
- Mitral valve prolapse
Correct answer: Resistant systemic hypertension
Untreated obstructive sleep apnea is strongly associated with resistant systemic hypertension, because repeated nocturnal hypoxemia and sympathetic surges raise blood pressure. Aortic stenosis, hypertrophic cardiomyopathy, and mitral valve prolapse are structural valvular or myocardial conditions not characteristically driven by sleep apnea.
- A 60-year-old man with obstructive sleep apnea cannot tolerate continuous positive airway pressure despite multiple mask trials and pressure adjustments. Which alternative therapy is most appropriate to offer next for his symptomatic disease?
- A nightly long-acting benzodiazepine
- A custom mandibular advancement oral appliance
- A daily decongestant nasal spray
- An over-the-counter antihistamine
Correct answer: A custom mandibular advancement oral appliance
A mandibular advancement oral appliance is an appropriate alternative for a patient intolerant of continuous positive airway pressure, because advancing the mandible enlarges the upper airway and reduces obstruction. Benzodiazepines depress respiratory drive and worsen apnea, while decongestants and antihistamines do not treat the underlying airway collapse.
- Among the following, which is the strongest modifiable risk factor for obstructive sleep apnea, such that weight reduction can meaningfully decrease disease severity?
- A history of childhood asthma
- Left-handedness
- Obesity
- A high dietary fiber intake
Correct answer: Obesity
Obesity is the strongest modifiable risk factor for obstructive sleep apnea, and weight loss can reduce the frequency of obstructive events by decreasing upper-airway soft-tissue and improving lung volumes. Childhood asthma, handedness, and dietary fiber intake are not established drivers of sleep-disordered breathing severity.
- A 45-year-old African American woman presents with dry cough, dyspnea, and bilateral hilar lymphadenopathy on chest radiograph. A biopsy of a mediastinal node shows noncaseating granulomas, and infections and malignancy are excluded. Which diagnosis is most consistent with these findings?
- Tuberculosis
- Lymphangitic carcinomatosis
- Silicosis
- Sarcoidosis
Correct answer: Sarcoidosis
Sarcoidosis is most consistent, because bilateral hilar lymphadenopathy with noncaseating granulomas in the absence of infection or malignancy is its hallmark presentation. Tuberculosis produces caseating granulomas, lymphangitic carcinomatosis reflects metastatic spread, and silicosis follows occupational dust exposure with distinct nodular fibrosis.
- A 60-year-old man develops acute hypoxemic respiratory failure within a day of severe sepsis. Chest imaging shows new bilateral infiltrates, the ratio of arterial oxygen to inspired oxygen fraction is reduced, and there is no evidence of cardiogenic pulmonary edema. Which ventilator strategy improves survival in this condition?
- Low tidal volume lung-protective ventilation
- High tidal volume to maximize oxygenation
- Permissive hyperoxia with 100% oxygen indefinitely
- Routine high-frequency oscillatory ventilation
Correct answer: Low tidal volume lung-protective ventilation
Low tidal volume lung-protective ventilation improves survival in acute respiratory distress syndrome by limiting ventilator-induced lung injury from overdistension. High tidal volumes worsen injury, sustained high oxygen concentrations add toxicity without benefit, and routine high-frequency oscillation has not improved outcomes in this setting.
- A 55-year-old current smoker is found to have an incidental solitary 9-millimeter solid pulmonary nodule on chest CT, with no prior imaging available for comparison. Given his risk factors, which management approach is most appropriate?
- Immediate surgical lobectomy without further workup
- Serial CT surveillance or further evaluation based on risk stratification
- Empiric chemotherapy for presumed malignancy
- Reassurance with no further imaging ever needed
Correct answer: Serial CT surveillance or further evaluation based on risk stratification
Risk-stratified follow-up with serial CT surveillance or further evaluation such as PET imaging is appropriate, because a solid solitary nodule of this intermediate size in a smoker warrants structured assessment rather than immediate surgery or a false assumption of benignity. Upfront lobectomy and empiric chemotherapy are premature without tissue diagnosis, and abandoning follow-up risks missing an evolving malignancy.
- A 52-year-old woman reports six months of symmetric pain and swelling in the small joints of both hands and wrists, with morning stiffness lasting more than an hour that improves with activity. Examination shows boggy synovitis of the metacarpophalangeal and proximal interphalangeal joints. Which pattern of joint involvement most strongly supports a diagnosis of rheumatoid arthritis rather than osteoarthritis?
- Distal interphalangeal joint involvement with bony Heberden nodes
- Symmetric metacarpophalangeal and proximal interphalangeal synovitis with prolonged morning stiffness
- Asymmetric large-joint pain worse with weight bearing and relieved by rest
- First carpometacarpal joint squaring without inflammatory swelling
Correct answer: Symmetric metacarpophalangeal and proximal interphalangeal synovitis with prolonged morning stiffness
Symmetric metacarpophalangeal and proximal interphalangeal synovitis with prolonged morning stiffness that improves with use is the classic inflammatory pattern of rheumatoid arthritis. Distal interphalangeal involvement with Heberden nodes and first carpometacarpal squaring are hallmarks of osteoarthritis, and pain relieved by rest with weight-bearing aggravation is also degenerative rather than inflammatory.
- A 45-year-old woman with newly diagnosed rheumatoid arthritis has persistent synovitis despite NSAIDs. According to current guideline-based management, which agent is the preferred first-line disease-modifying antirheumatic drug to initiate?
- Hydroxychloroquine alone for moderate-to-high disease activity
- Long-term oral prednisone monotherapy
- Adalimumab as initial single agent
- Methotrexate
Correct answer: Methotrexate
Methotrexate is the recommended anchor first-line disease-modifying antirheumatic drug for most patients with rheumatoid arthritis because of its proven efficacy and favorable long-term profile. Biologics such as adalimumab are typically reserved for inadequate response to conventional DMARDs, glucocorticoid monotherapy is avoided for chronic control, and hydroxychloroquine alone is insufficient for moderate-to-high disease activity.
- Before starting methotrexate in a patient with rheumatoid arthritis, which baseline and ongoing intervention most directly reduces the risk of hematologic and mucosal toxicity?
- Routine prophylactic platelet transfusion
- Daily folic acid supplementation
- Empiric broad-spectrum antibiotics
- Scheduled iron infusions
Correct answer: Daily folic acid supplementation
Daily folic acid supplementation reduces methotrexate-associated stomatitis, gastrointestinal upset, and cytopenias without compromising efficacy. Platelet transfusions, antibiotics, and iron infusions do not address the antifolate mechanism that drives methotrexate's mucosal and marrow toxicity.
- A 30-year-old woman has fatigue, a malar rash sparing the nasolabial folds, oral ulcers, and arthralgias. Which laboratory antibody is most specific for systemic lupus erythematosus and correlates with disease activity, particularly lupus nephritis?
- Rheumatoid factor
- Antinuclear antibody (ANA)
- Anti-double-stranded DNA antibody
- Anti-cyclic citrullinated peptide antibody
Correct answer: Anti-double-stranded DNA antibody
Anti-double-stranded DNA antibody is highly specific for systemic lupus erythematosus and rising titers often track disease activity and lupus nephritis. ANA is sensitive but not specific, while rheumatoid factor and anti-cyclic citrullinated peptide antibodies point toward rheumatoid arthritis.
- A 26-year-old woman with systemic lupus erythematosus develops new lower-extremity edema and 3.5 grams of proteinuria per day with an active urinary sediment. Which intervention is most appropriate to confirm the diagnosis and guide immunosuppressive therapy?
- Kidney biopsy
- Empiric high-dose loop diuretic alone
- Renal ultrasound followed by observation
- 24-hour urine for catecholamines
Correct answer: Kidney biopsy
Kidney biopsy is the standard for confirming and classifying lupus nephritis, because the histologic class directly determines whether and how aggressively to immunosuppress. Diuretics treat edema but not the underlying glomerular disease, ultrasound cannot establish histologic class, and urinary catecholamines evaluate pheochromocytoma, which is unrelated.
- Which medication is recommended as background therapy for essentially all patients with systemic lupus erythematosus because it reduces flares, organ damage, and mortality?
- Chronic high-dose prednisone
- Hydroxychloroquine
- Allopurinol
- Methotrexate
Correct answer: Hydroxychloroquine
Hydroxychloroquine is recommended for nearly all patients with systemic lupus erythematosus because it reduces disease flares, limits organ damage, and improves survival. Chronic high-dose glucocorticoids cause cumulative toxicity, allopurinol targets urate metabolism, and methotrexate addresses only selected manifestations rather than serving as universal background therapy.
- A 30-year-old woman with systemic lupus erythematosus has recurrent venous thromboses and a history of a mid-trimester fetal loss. Testing reveals a prolonged activated partial thromboplastin time that does not correct with mixing and positive anticardiolipin antibodies. Which complication does this profile indicate?
- Thrombotic thrombocytopenic purpura
- Disseminated intravascular coagulation
- Hemophilia A
- Antiphospholipid syndrome
Correct answer: Antiphospholipid syndrome
Recurrent thrombosis, pregnancy loss, a lupus anticoagulant that fails to correct on mixing, and antiphospholipid antibodies define antiphospholipid syndrome, which commonly accompanies systemic lupus erythematosus. Disseminated intravascular coagulation causes consumptive bleeding, hemophilia A causes a bleeding diathesis rather than thrombosis, and thrombotic thrombocytopenic purpura presents with microangiopathic hemolysis and a pentad of features.
- A 55-year-old man with hypertension and obesity wakes with abrupt severe pain, warmth, redness, and swelling of the first metatarsophalangeal joint. Arthrocentesis is performed. Which synovial fluid finding confirms the diagnosis of acute gout?
- Positively birefringent rhomboid calcium pyrophosphate crystals
- Negatively birefringent needle-shaped monosodium urate crystals
- Gram-positive cocci in clusters
- No crystals with a noninflammatory cell count under 200 per microliter
Correct answer: Negatively birefringent needle-shaped monosodium urate crystals
Negatively birefringent, needle-shaped monosodium urate crystals seen under polarized microscopy confirm acute gout. Positively birefringent rhomboid crystals indicate pseudogout from calcium pyrophosphate, gram-positive cocci suggest septic arthritis, and an acellular noninflammatory fluid argues against any crystal-induced flare.
- A 60-year-old man presents with an acute gout flare of the great toe and no contraindications to anti-inflammatory therapy. Which approach is appropriate first-line management of the acute attack?
- Immediate initiation of high-dose allopurinol to lower urate during the flare
- An NSAID, colchicine, or a glucocorticoid to control inflammation
- Urgent surgical joint debridement
- Empiric intravenous vancomycin
Correct answer: An NSAID, colchicine, or a glucocorticoid to control inflammation
Acute gout is treated with an anti-inflammatory agent such as an NSAID, colchicine, or a glucocorticoid to control the flare. Starting allopurinol during an acute attack can prolong or worsen it, surgery is not indicated, and antibiotics are reserved for septic arthritis, not crystal disease.
- A 58-year-old man has had three gout flares this year and a serum urate of 9.5 mg/dL. After the acute attack resolves, urate-lowering therapy is planned. Which agent is the recommended first-line urate-lowering drug, and what is the typical serum urate target?
- Colchicine alone to permanently normalize urate
- Probenecid titrated to a serum urate above 8 mg/dL
- Pegloticase as initial therapy for all patients
- Allopurinol titrated to a serum urate below 6 mg/dL
Correct answer: Allopurinol titrated to a serum urate below 6 mg/dL
Allopurinol is the recommended first-line urate-lowering therapy and is titrated to achieve a serum urate below 6 mg/dL to dissolve tophi and prevent recurrent flares. Probenecid is a second-line uricosuric, pegloticase is reserved for refractory tophaceous disease, and colchicine controls inflammation but does not lower urate.
- When initiating allopurinol for chronic gout, which co-prescription is recommended during the early months to prevent the increased flare frequency that often accompanies urate lowering?
- Low-dose colchicine or an NSAID as flare prophylaxis
- High-dose glucocorticoids continuously for one year
- A second xanthine oxidase inhibitor added simultaneously
- Empiric anticoagulation
Correct answer: Low-dose colchicine or an NSAID as flare prophylaxis
Low-dose colchicine or an NSAID is given as prophylaxis when starting urate-lowering therapy because mobilization of urate stores transiently increases flare risk. Continuous high-dose steroids, dual xanthine oxidase inhibitors, and anticoagulation are not standard flare-prophylaxis strategies.
- A 72-year-old woman reports new bitemporal headache, scalp tenderness when combing her hair, and jaw pain while chewing. Her erythrocyte sedimentation rate is markedly elevated. Which intervention should be initiated immediately, before biopsy confirmation, to prevent irreversible vision loss?
- Methotrexate monotherapy
- Low-dose aspirin alone
- High-dose systemic glucocorticoids
- Watchful waiting until biopsy results return
Correct answer: High-dose systemic glucocorticoids
High-dose systemic glucocorticoids should be started immediately when giant cell arteritis is suspected because delay risks sudden permanent blindness from anterior ischemic optic neuropathy. Aspirin and methotrexate are adjuncts, and waiting for biopsy results before treating is unsafe given the threat to vision.
- In a 70-year-old patient with suspected giant cell arteritis, which test remains the diagnostic standard for confirmation, and why does a recent start of steroids not preclude obtaining it?
- Antinuclear antibody titer, because it is specific for vasculitis
- Temporal artery biopsy, because characteristic histologic changes persist for weeks after starting glucocorticoids
- Random serum cortisol, because it reflects arterial inflammation
- Synovial fluid analysis, because it identifies vessel-wall crystals
Correct answer: Temporal artery biopsy, because characteristic histologic changes persist for weeks after starting glucocorticoids
Temporal artery biopsy is the diagnostic standard for giant cell arteritis, and because histologic inflammation persists for one to several weeks, treatment should not be withheld while awaiting it. ANA is not specific for this vasculitis, serum cortisol does not assess arteritis, and synovial fluid analysis is irrelevant to a large-vessel disease.
- A 73-year-old woman with new headache and an elevated sedimentation rate also reports several weeks of aching and morning stiffness in the shoulders and hips without true weakness. Which associated condition does this proximal limb-girdle presentation most likely represent?
- Polymyalgia rheumatica
- Polymyositis
- Fibromyalgia
- Osteoarthritis of the spine
Correct answer: Polymyalgia rheumatica
Proximal shoulder- and hip-girdle aching with morning stiffness and an elevated sedimentation rate in an older adult, frequently overlapping with giant cell arteritis, is characteristic of polymyalgia rheumatica. Polymyositis produces objective proximal weakness with elevated creatine kinase, fibromyalgia lacks an inflammatory marker elevation, and spinal osteoarthritis does not cause this systemic inflammatory girdle pattern.
- A 64-year-old obese woman reports several years of progressive right knee pain that worsens with activity, eases with rest, and is accompanied by brief morning stiffness under 30 minutes and crepitus. Radiographs show asymmetric joint-space narrowing and osteophytes. Which diagnosis best fits this presentation?
- Septic arthritis
- Rheumatoid arthritis
- Osteoarthritis
- Reactive arthritis
Correct answer: Osteoarthritis
Activity-related pain relieved by rest, morning stiffness under 30 minutes, crepitus, and radiographic osteophytes with asymmetric joint-space narrowing are classic for osteoarthritis. Rheumatoid arthritis produces prolonged morning stiffness and symmetric inflammatory synovitis, septic arthritis is acute and febrile, and reactive arthritis follows a triggering infection.
- A 68-year-old man with symptomatic knee osteoarthritis has inadequate relief from acetaminophen and topical agents. Besides pharmacologic therapy, which intervention has the strongest evidence for reducing pain and improving function in knee osteoarthritis?
- Daily oral glucosamine for guaranteed cartilage regeneration
- Routine arthroscopic lavage and debridement
- Long-term systemic opioids
- A structured exercise and weight-loss program
Correct answer: A structured exercise and weight-loss program
A structured exercise and weight-loss program is a cornerstone of knee osteoarthritis management with strong evidence for reducing pain and improving function. Arthroscopic lavage offers no benefit over sham, chronic opioids carry substantial harm without sustained benefit, and glucosamine does not reliably regenerate cartilage.
- A 68-year-old man with knee osteoarthritis develops abrupt monoarticular pain and swelling. Arthrocentesis shows weakly positively birefringent rhomboid-shaped crystals, and knee radiographs reveal linear calcification of the cartilage. Which condition does this represent?
- Hemarthrosis from anticoagulation
- Acute gouty arthritis
- Calcium pyrophosphate deposition disease (pseudogout)
- Avascular necrosis
Correct answer: Calcium pyrophosphate deposition disease (pseudogout)
Positively birefringent rhomboid crystals plus chondrocalcinosis on radiographs indicate calcium pyrophosphate deposition disease, known as pseudogout. Gout shows negatively birefringent needle-shaped urate crystals, hemarthrosis yields bloody fluid without crystals, and avascular necrosis produces subchondral collapse without crystals or chondrocalcinosis.
- A 26-year-old man has six months of insidious low back pain and stiffness that is worst in the morning, lasts over an hour, and improves with exercise. He also has alternating buttock pain and limited spinal flexion. Which diagnosis best explains this inflammatory back-pain pattern?
- Ankylosing spondylitis
- Lumbar disc herniation
- Mechanical low back strain
- Vertebral compression fracture
Correct answer: Ankylosing spondylitis
Insidious chronic low back pain in a young adult that is worse in the morning, improves with activity, and features alternating buttock pain and reduced spinal mobility is the inflammatory pattern of ankylosing spondylitis. Disc herniation and mechanical strain typically worsen with activity and lack prolonged morning stiffness, and compression fractures cause acute pain rather than chronic inflammatory stiffness.
- A 28-year-old man with suspected ankylosing spondylitis is found to be positive for which genetic marker that is strongly associated with the disease?
- HLA-B27
- HLA-DR4
- HLA-DQ2
- HLA-B51
Correct answer: HLA-B27
HLA-B27 is strongly associated with ankylosing spondylitis and the broader spondyloarthritis spectrum. HLA-DR4 associates with rheumatoid arthritis, HLA-DQ2 with celiac disease, and HLA-B51 with Behcet disease.
- A 35-year-old man develops acute asymmetric arthritis of the knee and ankle, conjunctivitis, and dysuria roughly three weeks after a bout of bacterial diarrhea. Which diagnosis best accounts for this constellation?
- Gout
- Septic arthritis
- Rheumatoid arthritis
- Reactive arthritis
Correct answer: Reactive arthritis
Asymmetric lower-extremity oligoarthritis with conjunctivitis and urethritis arising after a gastrointestinal or genitourinary infection is characteristic of reactive arthritis. Septic arthritis is a single acutely infected joint, rheumatoid arthritis is symmetric and chronic, and gout produces crystal-proven monoarthritis without the post-infectious triad.
- A 42-year-old woman with a long-standing scaly plaque rash develops dactylitis of a finger, nail pitting, and asymmetric arthritis involving distal interphalangeal joints. Which form of inflammatory arthritis does this presentation indicate?
- Psoriatic arthritis
- Rheumatoid arthritis
- Osteoarthritis
- Gonococcal arthritis
Correct answer: Psoriatic arthritis
A psoriatic skin rash with nail pitting, dactylitis (sausage digit), and distal interphalangeal joint involvement is characteristic of psoriatic arthritis. Rheumatoid arthritis spares the distal interphalangeal joints and is symmetric, osteoarthritis is noninflammatory, and gonococcal arthritis is an acute migratory infectious arthritis.
- A previously healthy 24-year-old sexually active woman presents with several days of migratory polyarthralgia, tenosynovitis of the wrist, and scattered pustular skin lesions, followed by a swollen, hot knee. Which organism is the most likely cause of this disseminated arthritis-dermatitis syndrome?
- Borrelia burgdorferi
- Staphylococcus aureus
- Neisseria gonorrhoeae
- Mycobacterium tuberculosis
Correct answer: Neisseria gonorrhoeae
Migratory polyarthralgia, tenosynovitis, and pustular skin lesions progressing to purulent arthritis in a young sexually active adult define disseminated gonococcal infection from Neisseria gonorrhoeae. Staphylococcus aureus typically causes a single non-migratory septic joint, Lyme arthritis follows a tick exposure with a target rash, and tuberculous arthritis is indolent and monoarticular.
- A 60-year-old man with diabetes presents with one day of a hot, swollen, exquisitely painful knee and fever, and is unable to bear weight. Which step is most critical before initiating antibiotics to evaluate for nongonococcal septic arthritis?
- Empiric oral antibiotics without joint aspiration
- Arthrocentesis with synovial fluid Gram stain, culture, and cell count
- MRI of the knee before any fluid sampling
- Serum uric acid measurement alone
Correct answer: Arthrocentesis with synovial fluid Gram stain, culture, and cell count
Arthrocentesis with Gram stain, culture, and cell count is essential to diagnose septic arthritis and guide antibiotics, since synovial fluid typically shows a markedly elevated neutrophil-predominant white cell count. Treating without aspiration risks missing the diagnosis, MRI delays definitive sampling, and serum uric acid cannot distinguish infection from crystal disease.
- A 50-year-old woman reports months of dry, gritty eyes and a dry mouth requiring water to swallow food, along with bilateral parotid swelling. Which autoantibodies are most characteristically associated with this syndrome?
- Anti-Ro (SSA) and anti-La (SSB) antibodies
- Anti-Scl-70 antibody
- Anti-Jo-1 antibody
- Anti-mitochondrial antibody
Correct answer: Anti-Ro (SSA) and anti-La (SSB) antibodies
Dry eyes, dry mouth, and parotid enlargement with anti-Ro (SSA) and anti-La (SSB) antibodies are characteristic of Sjogren syndrome. Anti-Scl-70 marks diffuse systemic sclerosis, anti-Jo-1 marks the antisynthetase form of myositis, and anti-mitochondrial antibody indicates primary biliary cholangitis.
- A 48-year-old woman has progressive skin thickening of the fingers and face, Raynaud phenomenon, and difficulty swallowing solids and liquids. She develops a hypertensive emergency with acute kidney injury. Which complication should be treated promptly with an ACE inhibitor?
- Goodpasture syndrome
- Lupus nephritis
- Scleroderma renal crisis
- Minimal change disease
Correct answer: Scleroderma renal crisis
Scleroderma renal crisis presents with abrupt severe hypertension and acute kidney injury in a patient with systemic sclerosis, and ACE inhibitors are the treatment of choice. Lupus nephritis, Goodpasture syndrome, and minimal change disease do not present as this hypertensive crisis-driven renal emergency in systemic sclerosis.
- A 45-year-old woman reports several weeks of progressive proximal muscle weakness causing difficulty climbing stairs and rising from a chair, with a heliotrope rash on the eyelids and scaly papules over the knuckles. Which diagnosis best explains these findings?
- Dermatomyositis
- Polymyalgia rheumatica
- Fibromyalgia
- Myasthenia gravis
Correct answer: Dermatomyositis
Symmetric proximal muscle weakness with a heliotrope rash and Gottron papules over the knuckles is characteristic of dermatomyositis, typically with elevated creatine kinase. Polymyalgia rheumatica causes stiffness without true weakness or rash, fibromyalgia lacks objective weakness, and myasthenia gravis causes fatigable weakness without these skin findings.
- A 38-year-old man presents with palpable purpura on the lower extremities, abdominal pain, arthralgias, and hematuria with red cell casts. Biopsy of a kidney shows IgA deposition. Which small-vessel vasculitis does this represent?
- IgA vasculitis (Henoch-Schonlein purpura)
- Giant cell arteritis
- Takayasu arteritis
- Polyarteritis nodosa
Correct answer: IgA vasculitis (Henoch-Schonlein purpura)
Palpable purpura, abdominal pain, arthralgias, and IgA-associated glomerulonephritis define IgA vasculitis (Henoch-Schonlein purpura), a small-vessel vasculitis. Giant cell arteritis and Takayasu arteritis affect large vessels, and polyarteritis nodosa is a medium-vessel vasculitis that spares the glomeruli and lacks IgA-dominant deposits.
- A 55-year-old man with chronic sinusitis, recurrent epistaxis, hemoptysis, and glomerulonephritis is found to have a positive cytoplasmic ANCA directed against proteinase 3. Which vasculitis is most consistent with this profile?
- IgA vasculitis
- Granulomatosis with polyangiitis
- Behcet disease
- Cryoglobulinemic vasculitis
Correct answer: Granulomatosis with polyangiitis
Upper-airway disease, pulmonary involvement, and glomerulonephritis with PR3-ANCA (c-ANCA) are characteristic of granulomatosis with polyangiitis. IgA vasculitis is IgA-mediated rather than ANCA-associated, Behcet disease features recurrent oral and genital ulcers, and cryoglobulinemic vasculitis is associated with hepatitis C and palpable purpura.
- A 60-year-old woman taking long-term glucocorticoids for polymyalgia rheumatica undergoes bone density testing showing a T-score of -2.6 at the spine. Which intervention is the first-line pharmacologic therapy to reduce her fracture risk?
- High-dose vitamin A
- A loop diuretic
- A bisphosphonate with adequate calcium and vitamin D
- An NSAID for bone strengthening
Correct answer: A bisphosphonate with adequate calcium and vitamin D
A bisphosphonate combined with adequate calcium and vitamin D is first-line therapy for osteoporosis, including glucocorticoid-induced osteoporosis with a T-score in the osteoporotic range. Loop diuretics increase urinary calcium loss, excess vitamin A harms bone, and NSAIDs do not treat osteoporosis.
- A 30-year-old man on chronic high-dose glucocorticoids for nephrotic syndrome develops insidious deep groin and hip pain worsened by weight bearing, with normal early radiographs. Which complication should be evaluated with MRI of the hip?
- Avascular necrosis of the femoral head
- Septic arthritis of the hip
- Trochanteric bursitis
- Lumbar radiculopathy
Correct answer: Avascular necrosis of the femoral head
Insidious weight-bearing hip or groin pain with normal early radiographs in a patient on chronic high-dose glucocorticoids should prompt MRI to detect avascular necrosis of the femoral head, which MRI identifies before plain films change. Septic arthritis is acute and febrile, trochanteric bursitis causes lateral point tenderness, and lumbar radiculopathy follows a dermatomal pattern.
- A 50-year-old warehouse worker has lateral elbow pain reproduced by resisted wrist extension and gripping, with tenderness at the lateral epicondyle but no joint swelling. Which condition does this overuse presentation represent?
- Lateral epicondylitis
- Olecranon bursitis
- Rheumatoid arthritis of the elbow
- Gouty arthritis
Correct answer: Lateral epicondylitis
Lateral epicondyle tenderness with pain on resisted wrist extension and gripping, without joint swelling, is the classic overuse tendinopathy of lateral epicondylitis. Olecranon bursitis presents as a posterior fluctuant swelling, rheumatoid arthritis causes synovitis with morning stiffness, and gout produces crystal-proven monoarthritis.
- A 55-year-old laborer reports shoulder pain with overhead activity, weakness on arm abduction and external rotation, and a positive drop-arm sign. Which musculoskeletal disorder best explains these findings?
- Cervical myelopathy
- Adhesive capsulitis with global passive restriction
- Acute septic arthritis of the shoulder
- Rotator cuff tendinopathy or tear
Correct answer: Rotator cuff tendinopathy or tear
Painful overhead motion, weakness on abduction and external rotation, and a positive drop-arm sign localize the problem to the rotator cuff. Adhesive capsulitis restricts passive as well as active range globally, septic arthritis is acutely hot and febrile, and cervical myelopathy produces long-tract neurologic signs rather than isolated cuff weakness.
- A 45-year-old office worker reports numbness and tingling of the thumb, index, and middle fingers that wakes her at night and worsens with typing, with a positive Tinel sign at the wrist. Which condition is most likely?
- Ulnar neuropathy at the elbow
- Carpal tunnel syndrome from median nerve compression
- Cervical radiculopathy at C5
- De Quervain tenosynovitis
Correct answer: Carpal tunnel syndrome from median nerve compression
Nocturnal paresthesias in the thumb, index, and middle fingers with a positive Tinel sign reflect median nerve compression at the wrist, or carpal tunnel syndrome. Ulnar neuropathy affects the fourth and fifth fingers, C5 radiculopathy causes shoulder-area symptoms, and De Quervain tenosynovitis causes radial-sided wrist pain on thumb movement.
- A 45-year-old woman reports widespread chronic musculoskeletal pain, fatigue, unrefreshing sleep, and cognitive fog, with multiple tender points but no synovitis, normal inflammatory markers, and normal radiographs. Which diagnosis best fits?
- Systemic lupus erythematosus
- Rheumatoid arthritis
- Polymyalgia rheumatica
- Fibromyalgia
Correct answer: Fibromyalgia
Chronic widespread pain with fatigue, nonrestorative sleep, cognitive symptoms, and tender points but normal inflammatory markers and imaging is characteristic of fibromyalgia. Rheumatoid arthritis and polymyalgia rheumatica show inflammatory features, and lupus produces serologic and multiorgan abnormalities absent here.
- A 35-year-old woman has color changes of the fingers triggered by cold, with sequential white, blue, and red phases, and no underlying connective tissue disease on evaluation. Which initial management is most appropriate for primary Raynaud phenomenon?
- Long-term systemic anticoagulation
- Cold avoidance and warming measures, with a dihydropyridine calcium channel blocker if needed
- Immediate digital sympathectomy
- High-dose glucocorticoids
Correct answer: Cold avoidance and warming measures, with a dihydropyridine calcium channel blocker if needed
Primary Raynaud phenomenon is managed first with cold avoidance and warming, adding a dihydropyridine calcium channel blocker such as nifedipine when symptoms persist. Anticoagulation, surgical sympathectomy, and glucocorticoids are not first-line for uncomplicated primary Raynaud.
- A 30-year-old woman from an endemic area develops a single swollen knee months after an untreated expanding erythematous rash with central clearing that followed a tick bite. Which diagnosis best explains this late monoarthritis?
- Gout
- Reactive arthritis
- Lyme arthritis
- Rheumatoid arthritis
Correct answer: Lyme arthritis
A large-joint monoarthritis weeks to months after an erythema migrans rash and tick exposure indicates Lyme arthritis from Borrelia burgdorferi. Reactive arthritis follows enteric or genitourinary infection, gout is crystal-induced, and rheumatoid arthritis is a chronic symmetric polyarthritis without this exposure history.
- A 78-year-old woman falls onto an outstretched hand and presents with wrist pain and a dorsally angulated deformity, with point tenderness over the distal radius. Radiographs confirm a distal radius fracture. Beyond fracture care, which underlying condition should be evaluated given this fragility fracture?
- Osteoarthritis
- Septic arthritis
- Gout
- Osteoporosis
Correct answer: Osteoporosis
A low-trauma distal radius fragility fracture in an older adult should prompt evaluation for osteoporosis, including bone density testing and treatment to prevent future fractures. Septic arthritis, gout, and osteoarthritis do not explain a fragility fracture and are not the underlying concern after a fall from standing height.
- A 40-year-old man with a chronic scaly plaque skin disease is being evaluated for joint complaints. Which radiographic finding is most characteristic of the destructive form of psoriatic arthritis?
- Chondrocalcinosis
- Symmetric marginal erosions of the metacarpophalangeal joints
- Pencil-in-cup deformity
- Punched-out periarticular erosions with overhanging edges
Correct answer: Pencil-in-cup deformity
The pencil-in-cup deformity from concurrent bone erosion and proliferation is characteristic of psoriatic arthritis mutilans. Symmetric marginal erosions suggest rheumatoid arthritis, chondrocalcinosis indicates calcium pyrophosphate deposition, and punched-out erosions with overhanging edges are seen in chronic tophaceous gout.
- A 30-year-old woman with systemic lupus erythematosus is counseled about reducing flares and accelerated atherosclerosis. Beyond medication adherence, which modifiable measure most directly reduces cutaneous and systemic flares?
- Avoidance of all vaccinations
- Routine prophylactic antibiotics
- A high-sodium diet
- Strict photoprotection with sunscreen and sun avoidance
Correct answer: Strict photoprotection with sunscreen and sun avoidance
Ultraviolet light triggers cutaneous and systemic lupus flares, so strict photoprotection with sunscreen and sun avoidance is an important nonpharmacologic measure. Routine antibiotics are not indicated, a high-sodium diet does not reduce flares, and appropriate vaccination is encouraged rather than avoided.
- A 55-year-old man with recurrent gout flares and a serum urate of 10 mg/dL also has chronic kidney disease and recurrent uric acid kidney stones. Which urate-lowering strategy and monitoring approach is most appropriate?
- Pegloticase as first-line for all patients regardless of severity
- A uricosuric agent to maximize urinary uric acid excretion
- No urate-lowering therapy despite tophi and stones
- Xanthine oxidase inhibition with allopurinol, titrated and monitored, to lower urate production
Correct answer: Xanthine oxidase inhibition with allopurinol, titrated and monitored, to lower urate production
In a patient with gout, chronic kidney disease, and uric acid stones, a xanthine oxidase inhibitor such as allopurinol lowers urate production and is preferred, whereas uricosurics that increase urinary uric acid would worsen stone risk. Withholding therapy despite tophi and stones is inappropriate, and pegloticase is reserved for refractory disease rather than first-line use.
- A 70-year-old man with polymyalgia rheumatica has been on glucocorticoids for several months. To limit cumulative steroid toxicity while controlling disease, which steroid-sparing agent is commonly considered in relapsing or steroid-dependent cases?
- Levothyroxine
- Allopurinol
- Methotrexate
- Vancomycin
Correct answer: Methotrexate
Methotrexate is a recognized steroid-sparing agent in relapsing or glucocorticoid-dependent polymyalgia rheumatica, helping reduce cumulative steroid exposure. Allopurinol lowers urate, levothyroxine treats hypothyroidism, and vancomycin is an antibiotic, none of which spares steroids in this condition.
- A 58-year-old woman with long-standing seropositive rheumatoid arthritis develops a swelling behind the knee and acute calf pain and swelling that mimics deep vein thrombosis. Ultrasound shows a fluid collection extending from the joint. Which complication does this represent?
- Acute gouty arthritis of the knee
- Ruptured Baker (popliteal) cyst
- Femoral head avascular necrosis
- Septic arthritis of the hip
Correct answer: Ruptured Baker (popliteal) cyst
A popliteal swelling that dissects into the calf and mimics deep vein thrombosis in a patient with rheumatoid arthritis indicates a ruptured Baker (popliteal) cyst. Gout produces crystal-proven joint inflammation, avascular necrosis causes deep hip pain on weight bearing, and septic arthritis presents with a hot infected joint and fever.
- A 78-year-old woman with mild baseline dementia becomes acutely confused at home over two days. Her daughter notes she has not had a bowel movement in five days and has been straining with little output. After confirming acute delirium, which reversible precipitant should be evaluated and addressed first in this presentation?
- A new occult malignancy
- Fecal impaction with constipation
- Early Parkinson disease
- Progression of her underlying dementia
Correct answer: Fecal impaction with constipation
Fecal impaction is a classic, frequently overlooked reversible precipitant of delirium in older adults, and the multi-day history of no bowel movement with straining points directly to it; relieving the impaction often resolves the acute confusion. An occult malignancy is far less likely to explain an acute two-day change. Parkinson disease develops gradually and does not present as acute delirium, and attributing the change to dementia progression would miss a treatable cause, since dementia worsens slowly rather than over days.
- An 82-year-old man hospitalized for pneumonia is at high risk for delirium. The team wants a brief, validated bedside tool a nurse can administer in under two minutes to screen for inattention and altered awareness during routine rounds. Which instrument is best suited for this rapid serial screening?
- The Patient Health Questionnaire-9 (PHQ-9)
- The Geriatric Depression Scale
- A brief delirium screen such as the 4AT
- The Montreal Cognitive Assessment (MoCA)
Correct answer: A brief delirium screen such as the 4AT
A brief delirium screening tool such as the 4AT is designed for rapid, repeated bedside use, assessing alertness, orientation, attention, and acute change in only a couple of minutes, making it ideal for serial nursing screens in at-risk inpatients. The PHQ-9 and Geriatric Depression Scale screen for depression, not delirium. The Montreal Cognitive Assessment is a longer test of chronic cognitive impairment and is too time-consuming and not designed for fluctuating acute screening.
- A 75-year-old man reports gradual difficulty hearing conversations, especially in noisy restaurants, and often misunderstands high-pitched voices. Audiometry shows symmetric high-frequency sensorineural hearing loss. Which age-related condition does this best represent, and why does it matter for his overall care?
- Presbycusis, which is associated with social isolation, depression, and accelerated cognitive decline if untreated
- Acute otitis media requiring antibiotics
- Cerumen impaction reversible with irrigation alone
- Otosclerosis presenting as conductive loss
Correct answer: Presbycusis, which is associated with social isolation, depression, and accelerated cognitive decline if untreated
Presbycusis is age-related, typically symmetric, high-frequency sensorineural hearing loss, and recognizing it matters because untreated hearing loss in older adults is linked to social isolation, depression, and accelerated cognitive decline, so amplification can improve function and quality of life. Acute otitis media is an acute infection with pain and effusion. Cerumen impaction causes conductive, often unilateral and reversible loss. Otosclerosis produces a conductive rather than sensorineural pattern.
- A 70-year-old man being evaluated in a memory clinic has measurable memory complaints confirmed on testing, but he remains fully independent in all of his daily activities and does not meet criteria for dementia. Which term best describes this intermediate cognitive state?
- Normal age-related cognitive change
- Mild cognitive impairment
- Major neurocognitive disorder
- Delirium
Correct answer: Mild cognitive impairment
Mild cognitive impairment is the correct term for objective cognitive decline beyond what is expected for age while functional independence in daily activities is preserved and full dementia criteria are not met. Normal age-related change would not show objective deficits on testing beyond expected norms. Major neurocognitive disorder (dementia) requires impairment significant enough to interfere with independence. Delirium is an acute, fluctuating disturbance of attention, not a stable chronic state.
- An 80-year-old man with moderate dementia becomes increasingly agitated, restless, and verbally aggressive in the late afternoon and evening. There is no fever, no new medication, and his vital signs are normal. Which initial management strategy is most appropriate for these behavioral and psychological symptoms of dementia?
- Start a standing benzodiazepine each afternoon for sedation
- Identify triggers and use nonpharmacologic behavioral approaches as first-line management
- Begin a typical antipsychotic immediately as first-line therapy
- Apply physical restraints during the evening hours
Correct answer: Identify triggers and use nonpharmacologic behavioral approaches as first-line management
Behavioral and psychological symptoms of dementia, including evening agitation often called sundowning, are best managed first by identifying and modifying triggers and using nonpharmacologic approaches such as structured routines, adequate lighting, and addressing unmet needs. Standing benzodiazepines increase confusion and falls. Antipsychotics carry a boxed warning for increased mortality in dementia and are reserved for severe, dangerous symptoms after nonpharmacologic measures fail. Restraints worsen agitation and risk injury.
- A 79-year-old man with benign prostatic hyperplasia reports constant dribbling of small amounts of urine and a sensation of incomplete emptying. Post-void residual volume is markedly elevated at 350 mL. Which type of urinary incontinence does this presentation best represent?
- Stress urinary incontinence
- Urge incontinence from detrusor overactivity
- Overflow incontinence
- Functional incontinence
Correct answer: Overflow incontinence
Overflow incontinence is the best fit, characterized by continuous dribbling, a sense of incomplete emptying, and a markedly elevated post-void residual, typically from bladder outlet obstruction such as benign prostatic hyperplasia or from impaired detrusor contractility. Stress incontinence causes leakage with increased intra-abdominal pressure and a normal residual. Urge incontinence features sudden urgency without retention, and functional incontinence results from inability to reach the toilet despite an intact urinary tract.
- A 76-year-old woman recovering in the hospital has progressive loss of skeletal muscle mass and strength, with reduced grip strength and slow gait speed but no acute inflammatory illness. Which age-related condition does this loss of muscle mass and function most specifically describe?
- Sarcopenia
- Osteoporosis
- Hypothyroid myopathy
- Polymyalgia rheumatica
Correct answer: Sarcopenia
Sarcopenia is the age-associated loss of skeletal muscle mass combined with reduced muscle strength and physical performance, reflected here by low grip strength and slow gait speed, and it contributes to frailty, falls, and disability. Osteoporosis is loss of bone, not muscle. Hypothyroid myopathy would accompany other features of hypothyroidism and abnormal thyroid testing. Polymyalgia rheumatica causes proximal pain and stiffness with elevated inflammatory markers rather than painless progressive muscle wasting.
- A 77-year-old woman who lives alone is admitted with poor oral intake. The team wants a validated screening tool to identify older adults who are malnourished or at risk for malnutrition. Which instrument is specifically designed for this purpose in geriatric patients?
- The CHA2DS2-VASc score
- The Mini Nutritional Assessment
- The Glasgow Coma Scale
- The Wells score
Correct answer: The Mini Nutritional Assessment
The Mini Nutritional Assessment is the validated tool developed specifically to screen older adults for malnutrition and malnutrition risk, incorporating intake, weight change, mobility, and anthropometric measures. The CHA2DS2-VASc score estimates stroke risk in atrial fibrillation, the Glasgow Coma Scale grades level of consciousness, and the Wells score estimates venous thromboembolism probability, none of which assess nutritional status in geriatric patients.
- An 84-year-old man with advanced dementia is hospitalized for aspiration pneumonia, and the family asks whether placing a percutaneous feeding tube will help him. Based on current evidence, which statement best guides counseling about tube feeding in advanced dementia?
- Tube feeding clearly prevents aspiration pneumonia in advanced dementia
- Tube feeding reliably prolongs survival and should be offered to all such patients
- Tube feeding does not improve survival or prevent aspiration and careful hand feeding is generally preferred
- Tube feeding consistently improves pressure ulcer healing and quality of life
Correct answer: Tube feeding does not improve survival or prevent aspiration and careful hand feeding is generally preferred
In advanced dementia, evidence shows percutaneous feeding tubes do not improve survival, do not prevent aspiration pneumonia, and do not reliably improve pressure ulcers or quality of life, so careful hand feeding aligned with comfort and goals of care is generally preferred. Claims that tube feeding prevents aspiration, prolongs survival, or heals pressure ulcers are not supported by the evidence and can mislead families during decision-making.
- A hospitalized 83-year-old woman with delirium must decide whether to undergo a recommended procedure. Which set of abilities must the clinician assess to determine whether she has the capacity to make this specific medical decision?
- Her orientation to person, place, and time only
- Her ability to understand the information, appreciate how it applies to her, reason about options, and communicate a choice
- Whether her score on a standardized cognitive test exceeds a fixed cutoff
- Whether she agrees with the physician's recommendation
Correct answer: Her ability to understand the information, appreciate how it applies to her, reason about options, and communicate a choice
Decision-making capacity is determined by four functional abilities: understanding the relevant information, appreciating how it applies to one's own situation, reasoning through the options, and communicating a consistent choice. Orientation alone is insufficient, and capacity is decision-specific rather than defined by a single cognitive test cutoff. Agreeing with the physician is not the standard, because a patient who declines a recommendation can still possess full capacity.
- An 81-year-old woman with worsening heart failure and recurrent hospitalizations is cognitively intact. Her physician wants to discuss and document her values and preferences for future care, including whom she would want to make decisions if she could not. Which action best accomplishes this goal?
- Engage in advance care planning and help her designate a healthcare proxy
- Wait until she loses capacity before any discussion of preferences
- Automatically enter a do-not-resuscitate order without discussion
- Defer entirely to her adult children's wishes
Correct answer: Engage in advance care planning and help her designate a healthcare proxy
Advance care planning, including clarifying values, discussing goals of care, and designating a healthcare proxy (durable power of attorney for health care), is the appropriate action while the patient retains capacity, ensuring her wishes guide future care. Waiting until she loses capacity defeats the purpose. Entering a do-not-resuscitate order without discussion violates patient autonomy, and deferring to family rather than the patient herself ignores her right to direct her own care.
- A 79-year-old man who was admitted ambulatory is kept on bed rest for several days during a hospital stay. He subsequently develops weakness, a pressure injury, orthostatic intolerance, and difficulty walking. Which geriatric problem do these linked complications of prolonged inactivity best illustrate?
- Hazards of immobility (deconditioning) in hospitalized older adults
- Normal physiologic aging unrelated to hospitalization
- An acute stroke causing all of the deficits
- A primary psychiatric disorder
Correct answer: Hazards of immobility (deconditioning) in hospitalized older adults
These clustered complications, muscle weakness, pressure injury, orthostatic intolerance, and impaired gait, illustrate the hazards of immobility and hospital-associated deconditioning, which develop rapidly in older adults on bed rest and are largely preventable with early mobilization. They are not simply normal aging, as they were precipitated by inactivity. A single stroke would typically cause focal deficits, and the constellation is not explained by a primary psychiatric disorder.
- An 82-year-old woman with Parkinson disease coughs and chokes during meals and has had two episodes of pneumonia. A bedside swallow evaluation shows difficulty initiating swallowing and delayed laryngeal elevation. Which complication is she at greatest risk for if this swallowing problem is not addressed?
- Diverticulitis
- Aspiration pneumonia
- Cholelithiasis
- Peptic ulcer disease
Correct answer: Aspiration pneumonia
Dysphagia in older adults, particularly with neurologic disease such as Parkinson disease, predisposes to aspiration of food and secretions into the airway, making aspiration pneumonia the greatest risk, which is why swallow evaluation and diet or texture modification are important. Diverticulitis, cholelithiasis, and peptic ulcer disease are gastrointestinal conditions unrelated to the mechanics of impaired swallowing and laryngeal protection during meals.
- A 78-year-old woman with no prior urinary problems develops new daytime and nighttime urine leakage shortly after starting a diuretic and while being treated for a urinary tract infection. Before pursuing a chronic incontinence diagnosis, which approach is most appropriate for this new-onset incontinence?
- Immediately begin a long-term antimuscarinic medication
- Place a chronic indwelling catheter to manage the leakage
- Conclude she has irreversible age-related incontinence
- Evaluate for and treat transient, reversible causes such as infection and medication effects
Correct answer: Evaluate for and treat transient, reversible causes such as infection and medication effects
New-onset incontinence in an older adult should first prompt evaluation for transient, reversible causes, classically remembered by the DIAPPERS mnemonic, which includes delirium, infection, atrophic vaginitis, pharmaceuticals such as diuretics, psychological factors, excess urine output, restricted mobility, and stool impaction. Treating the urinary tract infection and reviewing the new diuretic may resolve the problem. Starting a chronic antimuscarinic or placing an indwelling catheter is premature, and labeling it irreversible aging would miss a treatable cause.
- A 72-year-old man with hypertension and diabetes is found to have an irregularly irregular pulse, and an electrocardiogram confirms atrial fibrillation. His CHA2DS2-VASc score is calculated to be 4. What is the most appropriate long-term therapy to reduce his risk of stroke?
- Aspirin 81 mg daily
- Clopidogrel monotherapy
- No antithrombotic therapy with annual monitoring
- A direct oral anticoagulant such as apixaban
Correct answer: A direct oral anticoagulant such as apixaban
A direct oral anticoagulant such as apixaban is most appropriate because a CHA2DS2-VASc score of 4 indicates high thromboembolic risk, and oral anticoagulation provides substantially greater stroke prevention than antiplatelet therapy in atrial fibrillation. Direct oral anticoagulants are preferred over warfarin in most patients without mechanical valves or moderate-to-severe mitral stenosis. Aspirin offers minimal protection at this risk level, clopidogrel monotherapy is inferior to anticoagulation, and withholding therapy would leave a high-risk patient unprotected.
- Which feature on physical examination and electrocardiography is most characteristic of atrial fibrillation?
- A regular pulse with a fixed PR interval and present P waves
- An irregularly irregular pulse with absent discrete P waves and an irregular ventricular response
- A regular bradycardia with cannon a waves
- A regularly irregular pulse with a sawtooth baseline
Correct answer: An irregularly irregular pulse with absent discrete P waves and an irregular ventricular response
An irregularly irregular pulse with absent discrete P waves and an irregular ventricular response is the hallmark of atrial fibrillation, reflecting chaotic atrial electrical activity that conducts unpredictably through the atrioventricular node. The fibrillatory baseline replaces organized P waves. A regular pulse with present P waves describes normal sinus rhythm, regular bradycardia with cannon a waves suggests atrioventricular dissociation, and a regularly irregular sawtooth pattern is more typical of atrial flutter with variable block.
- A 68-year-old woman with newly diagnosed atrial fibrillation has a resting heart rate of 130 beats per minute and mild exertional dyspnea but stable blood pressure. She has no preexcitation. Which agent is most appropriate for initial rate control?
- Intravenous adenosine
- An intravenous beta-blocker such as metoprolol
- Intravenous epinephrine
- Oral flecainide alone
Correct answer: An intravenous beta-blocker such as metoprolol
An intravenous beta-blocker such as metoprolol is most appropriate for initial rate control because beta-blockers slow conduction through the atrioventricular node and are first-line for controlling the ventricular rate in hemodynamically stable atrial fibrillation. Nondihydropyridine calcium channel blockers are an alternative. Adenosine only transiently blocks the node and does not provide sustained rate control, epinephrine would accelerate the rate, and flecainide is a rhythm-control antiarrhythmic that should not be used alone in atrial fibrillation without atrioventricular nodal blockade.
- A 75-year-old man with persistent atrial fibrillation presents with acute pulmonary edema, a blood pressure of 78/44 mmHg, and a heart rate of 165 beats per minute. He is diaphoretic and confused. What is the most appropriate immediate management?
- Oral digoxin loading
- Synchronized direct-current cardioversion
- Intravenous fluid bolus and observation
- Scheduled outpatient ablation
Correct answer: Synchronized direct-current cardioversion
Synchronized direct-current cardioversion is the most appropriate immediate management because the patient has hemodynamic instability with hypotension, pulmonary edema, and altered mental status driven by the rapid atrial fibrillation, and prompt restoration of sinus rhythm is required. Pharmacologic rate control acts too slowly in an unstable patient. Oral digoxin has a delayed onset, a fluid bolus could worsen pulmonary edema, and outpatient ablation does not address an acute emergency.
- In a patient with atrial fibrillation, which components contribute points to the CHA2DS2-VASc score used to estimate stroke risk?
- Serum creatinine, liver enzymes, and platelet count
- Left ventricular ejection fraction and QRS duration only
- Cholesterol level, smoking status, and family history
- Congestive heart failure, hypertension, age, diabetes, prior stroke, vascular disease, and sex category
Correct answer: Congestive heart failure, hypertension, age, diabetes, prior stroke, vascular disease, and sex category
Congestive heart failure, hypertension, age, diabetes, prior stroke or transient ischemic attack, vascular disease, and sex category are the components of the CHA2DS2-VASc score, which estimates annual thromboembolic risk and guides anticoagulation decisions in atrial fibrillation. Prior stroke and advanced age carry the heaviest weight. Serum creatinine and platelets relate to bleeding risk scores instead, ejection fraction and QRS duration are not part of this score, and lipids and smoking are general cardiovascular risk factors not included.
- A 58-year-old woman with paroxysmal atrial fibrillation and no structural heart disease wishes to maintain sinus rhythm. Echocardiography shows a normal left ventricle and no significant coronary disease on prior evaluation. Which antiarrhythmic strategy is most appropriate for rhythm control in this setting?
- Amiodarone as the obligatory first-line agent
- A class IC agent such as flecainide combined with an atrioventricular nodal blocker
- Digoxin monotherapy for rhythm control
- Sotalol contraindicated by her normal heart
Correct answer: A class IC agent such as flecainide combined with an atrioventricular nodal blocker
A class IC agent such as flecainide combined with an atrioventricular nodal blocking drug is most appropriate because class IC antiarrhythmics are effective and preferred for rhythm control in patients without significant structural heart disease or coronary artery disease. The atrioventricular nodal blocker prevents rapid conduction if atrial flutter develops. Amiodarone is reserved for patients with structural disease or when other agents fail, digoxin controls rate but not rhythm, and sotalol can be used in a structurally normal heart, so it is not contraindicated here.
- A 55-year-old man presents with crushing substernal chest pain radiating to the left arm, diaphoresis, and nausea for 40 minutes. His electrocardiogram shows ST-segment elevation in leads II, III, and aVF. What is the most appropriate immediate reperfusion strategy if a catheterization laboratory is available within 90 minutes?
- Primary percutaneous coronary intervention
- Fibrinolytic therapy with alteplase
- Elective coronary artery bypass grafting in 48 hours
- Outpatient stress testing
Correct answer: Primary percutaneous coronary intervention
Primary percutaneous coronary intervention is the most appropriate strategy because the patient has an inferior ST-elevation myocardial infarction, and timely catheter-based reperfusion is superior to fibrinolysis when it can be performed promptly by an experienced center. Restoring coronary flow quickly limits infarct size and improves survival. Fibrinolytic therapy is reserved for when timely intervention is unavailable, urgent bypass is not the default reperfusion approach, and outpatient stress testing is dangerously inappropriate during an acute infarction.
- Which set of findings best distinguishes a non-ST-elevation myocardial infarction from unstable angina within the acute coronary syndrome spectrum?
- The presence of ST-segment elevation on the electrocardiogram
- Relief of pain with sublingual nitroglycerin
- A normal coronary angiogram
- Elevated cardiac troponin levels indicating myocardial necrosis
Correct answer: Elevated cardiac troponin levels indicating myocardial necrosis
Elevated cardiac troponin levels indicating myocardial necrosis distinguish non-ST-elevation myocardial infarction from unstable angina, since both present with ischemic symptoms and no ST elevation but only infarction releases troponin from dying myocytes. The troponin rise defines the infarction. ST-segment elevation would instead define a STEMI, relief with nitroglycerin does not differentiate the two diagnoses, and a normal angiogram is not used to separate these acute coronary syndrome subtypes.
- A 62-year-old woman is diagnosed with a non-ST-elevation myocardial infarction. She is hemodynamically stable with ongoing mild chest discomfort. In addition to aspirin and anticoagulation, which medication class most directly reduces myocardial oxygen demand by lowering heart rate and contractility?
- A beta-blocker such as metoprolol
- A loop diuretic such as furosemide
- A dihydropyridine calcium channel blocker such as amlodipine
- An inhaled bronchodilator
Correct answer: A beta-blocker such as metoprolol
A beta-blocker such as metoprolol most directly reduces myocardial oxygen demand because it lowers heart rate, contractility, and blood pressure, decreasing cardiac work during acute coronary syndrome and reducing ischemia and arrhythmia risk in stable patients. This benefit is central to early management. A loop diuretic treats volume overload rather than ischemic demand, dihydropyridine calcium channel blockers can reflexively increase heart rate, and inhaled bronchodilators have no role in reducing cardiac oxygen demand.
- A 70-year-old man presents 6 hours after symptom onset with a large anterior STEMI. He becomes hypotensive with cool extremities, elevated jugular venous pressure, and pulmonary congestion. His blood pressure is 80/50 mmHg despite no signs of bleeding. Which complication is most likely responsible for his deterioration?
- Anaphylaxis to contrast dye
- Hypovolemia from dehydration
- Cardiogenic shock from extensive left ventricular dysfunction
- Vasovagal syncope
Correct answer: Cardiogenic shock from extensive left ventricular dysfunction
Cardiogenic shock from extensive left ventricular dysfunction is most likely because a large anterior infarction can destroy enough myocardium to cause pump failure, producing hypotension, poor perfusion, elevated filling pressures, and pulmonary congestion. The combination of low output and congestion points to the heart as the failing pump. Anaphylaxis would cause vasodilation rather than congestion, hypovolemia would lower jugular venous pressure, and vasovagal syncope is transient and not associated with pulmonary edema.
- A 64-year-old man with heart failure and a left ventricular ejection fraction of 28 percent remains symptomatic on lisinopril and carvedilol. Which medication class, added to standard therapy, has been shown to reduce mortality further by blocking aldosterone?
- A nondihydropyridine calcium channel blocker
- A mineralocorticoid receptor antagonist such as spironolactone
- A class I antiarrhythmic
- An alpha-blocker such as doxazosin
Correct answer: A mineralocorticoid receptor antagonist such as spironolactone
A mineralocorticoid receptor antagonist such as spironolactone reduces mortality in heart failure with reduced ejection fraction by antagonizing aldosterone, limiting sodium retention and adverse cardiac remodeling. It is a core component of guideline-directed medical therapy for symptomatic patients with low ejection fraction. Nondihydropyridine calcium channel blockers are generally avoided because they depress contractility, class I antiarrhythmics can increase mortality in this population, and alpha-blockers have no survival benefit in heart failure.
- Which four medication classes form the foundational pillars of guideline-directed medical therapy for heart failure with reduced ejection fraction?
- A loop diuretic, digoxin, aspirin, and a statin
- An ARNI or ACE inhibitor, a beta-blocker, a mineralocorticoid receptor antagonist, and an SGLT2 inhibitor
- A dihydropyridine calcium channel blocker, nitrates, and a fibrate
- An anticoagulant, an antihistamine, and a proton pump inhibitor
Correct answer: An ARNI or ACE inhibitor, a beta-blocker, a mineralocorticoid receptor antagonist, and an SGLT2 inhibitor
An angiotensin receptor-neprilysin inhibitor or ACE inhibitor, a beta-blocker, a mineralocorticoid receptor antagonist, and an SGLT2 inhibitor are the four foundational pillars of therapy for heart failure with reduced ejection fraction, each independently reducing mortality and hospitalization. Together they target the neurohormonal pathways driving disease progression. Loop diuretics relieve congestion but do not improve survival, calcium channel blockers and fibrates are not foundational, and anticoagulants and acid suppressants are not part of the core regimen.
- A 66-year-old man with heart failure and reduced ejection fraction presents with worsening orthopnea, weight gain of 5 kilograms, jugular venous distension, and bilateral pitting edema. His blood pressure is adequate. Which medication most rapidly relieves these congestive symptoms?
- An oral beta-blocker uptitration
- Initiation of an SGLT2 inhibitor
- An intravenous loop diuretic such as furosemide
- A mineralocorticoid receptor antagonist
Correct answer: An intravenous loop diuretic such as furosemide
An intravenous loop diuretic such as furosemide most rapidly relieves congestion because it promotes diuresis of the excess sodium and water responsible for the edema, elevated jugular venous pressure, and orthopnea in acute decompensated heart failure. Rapid decongestion improves symptoms quickly. Beta-blocker uptitration can transiently worsen acute decompensation, SGLT2 inhibitors and mineralocorticoid receptor antagonists provide longer-term mortality benefit rather than rapid symptom relief during acute volume overload.
- A 60-year-old woman with heart failure and an ejection fraction of 25 percent remains in NYHA class II to III despite optimal medical therapy. Her electrocardiogram shows sinus rhythm with a left bundle branch block and a QRS duration of 160 milliseconds. Which device therapy is most likely to improve her symptoms and survival?
- Cardiac resynchronization therapy
- A permanent single-chamber pacemaker for bradycardia
- An intra-aortic balloon pump
- Catheter ablation of the atrioventricular node
Correct answer: Cardiac resynchronization therapy
Cardiac resynchronization therapy is most likely to help because patients with a low ejection fraction, persistent symptoms despite medical therapy, sinus rhythm, and a wide QRS with left bundle branch block benefit from biventricular pacing that restores coordinated contraction. This improves symptoms, ejection fraction, and survival. A standard pacemaker does not resynchronize the ventricles, an intra-aortic balloon pump is a temporary support device, and atrioventricular node ablation alone would not address the dyssynchrony.
- A 78-year-old man reports exertional dyspnea, angina, and a syncopal episode. On examination there is a harsh late-peaking systolic ejection murmur at the right upper sternal border that radiates to the carotids, with a diminished and delayed carotid upstroke. Which valvular lesion is most consistent with these findings?
- Mitral regurgitation
- Tricuspid stenosis
- Aortic stenosis
- Pulmonary regurgitation
Correct answer: Aortic stenosis
Aortic stenosis is most consistent because the classic triad of angina, syncope, and dyspnea together with a harsh late-peaking systolic murmur radiating to the carotids and a slow, weak carotid upstroke (pulsus parvus et tardus) reflects obstruction to left ventricular outflow. These features define severe aortic stenosis. Mitral regurgitation produces a holosystolic murmur at the apex, tricuspid stenosis causes a diastolic right-sided murmur, and pulmonary regurgitation produces a diastolic murmur, none matching this presentation.
- A 80-year-old man has severe symptomatic aortic stenosis confirmed by echocardiography. He is considered to be at intermediate to high surgical risk because of age and comorbidities. Which intervention is most appropriate to relieve the obstruction?
- Long-term vasodilator therapy alone
- Balloon valvuloplasty as definitive therapy
- Transcatheter aortic valve replacement
- Watchful waiting until heart failure develops
Correct answer: Transcatheter aortic valve replacement
Transcatheter aortic valve replacement is most appropriate because symptomatic severe aortic stenosis requires valve replacement, and a transcatheter approach is preferred for many older patients at intermediate or high surgical risk. Definitive relief of the outflow obstruction improves symptoms and survival. Vasodilators do not relieve fixed obstruction and can cause hypotension, balloon valvuloplasty offers only temporary benefit in adults, and waiting once symptoms appear carries a high mortality risk.
- Which echocardiographic measurements are used to grade the severity of aortic stenosis?
- Left atrial volume index and tricuspid regurgitant velocity only
- Pulmonary artery systolic pressure and right ventricular thickness
- Mitral inflow E/A ratio and ejection fraction alone
- Aortic valve area, mean transvalvular pressure gradient, and peak aortic jet velocity
Correct answer: Aortic valve area, mean transvalvular pressure gradient, and peak aortic jet velocity
Aortic valve area, mean transvalvular pressure gradient, and peak aortic jet velocity are the key measurements used to grade aortic stenosis severity, with severe disease defined by a small valve area, a high mean gradient, and a high jet velocity. These hemodynamic parameters quantify the degree of obstruction. Left atrial volume and tricuspid velocity assess other conditions, pulmonary pressures and right ventricular thickness reflect downstream effects, and mitral inflow indices evaluate diastolic function rather than aortic valve severity.
- A 45-year-old man is found to have a blood pressure of 158/96 mmHg on three separate visits despite lifestyle modification. He has no diabetes or chronic kidney disease. Which class of medication is an appropriate first-line agent for his hypertension?
- An alpha-blocker such as terazosin
- A central alpha-2 agonist such as clonidine
- A loop diuretic such as furosemide
- A thiazide diuretic such as chlorthalidone
Correct answer: A thiazide diuretic such as chlorthalidone
A thiazide-type diuretic such as chlorthalidone is an appropriate first-line agent because thiazides, along with ACE inhibitors, angiotensin receptor blockers, and dihydropyridine calcium channel blockers, are recommended initial therapies for primary hypertension. They effectively lower blood pressure and reduce cardiovascular events. Alpha-blockers and central agonists are not first-line because of side effects and inferior outcomes, and loop diuretics are generally reserved for patients with heart failure or significant renal impairment rather than routine hypertension.
- According to current guidelines, which blood pressure threshold defines stage 1 hypertension in adults?
- A systolic pressure of 120 to 129 mmHg with a diastolic below 80 mmHg
- A systolic pressure of 130 to 139 mmHg or a diastolic pressure of 80 to 89 mmHg
- A systolic pressure of 160 mmHg or higher
- A diastolic pressure of 70 mmHg or higher
Correct answer: A systolic pressure of 130 to 139 mmHg or a diastolic pressure of 80 to 89 mmHg
A systolic pressure of 130 to 139 mmHg or a diastolic pressure of 80 to 89 mmHg defines stage 1 hypertension under current classification, prompting risk assessment and often pharmacologic therapy in higher-risk patients. This category sits between elevated blood pressure and stage 2. A systolic of 120 to 129 with diastolic below 80 is elevated blood pressure rather than hypertension, a systolic of 160 or higher is well within stage 2, and a diastolic of 70 is normal.
- A 52-year-old woman with type 2 diabetes and microalbuminuria is diagnosed with hypertension. Which antihypertensive class is particularly favored in this patient because of its additional kidney-protective effect?
- A peripheral alpha-blocker
- An ACE inhibitor or angiotensin receptor blocker
- A central alpha-2 agonist
- A direct arterial vasodilator such as hydralazine alone
Correct answer: An ACE inhibitor or angiotensin receptor blocker
An ACE inhibitor or angiotensin receptor blocker is particularly favored because these agents reduce intraglomerular pressure and slow the progression of diabetic kidney disease while lowering blood pressure, making them preferred in patients with diabetes and albuminuria. Their renoprotective benefit extends beyond blood pressure control. Alpha-blockers and central agonists lack this kidney protection, and hydralazine used alone causes reflex tachycardia and fluid retention without the renal benefit.
- A 38-year-old man presents with severe difficult-to-control hypertension, episodic headaches, palpitations, and drenching sweats. Plasma and urine metanephrines are markedly elevated. Which secondary cause of hypertension is most likely?
- Primary hyperaldosteronism
- Essential hypertension
- White coat hypertension
- Pheochromocytoma
Correct answer: Pheochromocytoma
Pheochromocytoma is most likely because the episodic triad of headache, palpitations, and diaphoresis with resistant hypertension and elevated metanephrines reflects excess catecholamine secretion from a chromaffin-cell tumor. Confirmatory biochemical testing precedes imaging and surgical resection. Primary hyperaldosteronism typically presents with hypokalemia rather than catecholamine surges, essential hypertension lacks the paroxysmal symptoms and biochemical findings, and white coat hypertension is elevated readings only in the clinical setting.
- A 60-year-old man arrives with a blood pressure of 220/130 mmHg, a severe headache, blurred vision, and new confusion. Funduscopy shows papilledema. Which term best describes this condition requiring prompt blood pressure reduction?
- Hypertensive urgency without organ damage
- Isolated systolic hypertension
- A hypertensive emergency with target-organ damage
- Masked hypertension
Correct answer: A hypertensive emergency with target-organ damage
A hypertensive emergency with target-organ damage best describes this presentation because severely elevated blood pressure accompanied by acute neurologic dysfunction and papilledema indicates ongoing end-organ injury that requires controlled intravenous blood pressure lowering. The presence of organ damage defines the emergency. Hypertensive urgency lacks acute organ injury, isolated systolic hypertension refers to an elevated systolic with normal diastolic without acute features, and masked hypertension describes normal clinic but elevated out-of-office readings.
- A 68-year-old woman is found to have a midsystolic click followed by a late systolic murmur best heard at the apex. The click moves earlier with standing. Which valvular abnormality does this finding most likely represent?
- Aortic regurgitation
- Pulmonic stenosis
- Tricuspid regurgitation
- Mitral valve prolapse
Correct answer: Mitral valve prolapse
Mitral valve prolapse is most likely because a midsystolic click followed by a late systolic murmur, with the click moving earlier when standing reduces ventricular volume, is the classic auscultatory signature of a prolapsing mitral leaflet. Maneuvers that decrease preload accentuate the finding. Aortic regurgitation produces an early diastolic murmur, pulmonic stenosis causes a systolic ejection murmur at the left upper sternal border, and tricuspid regurgitation produces a holosystolic murmur that increases with inspiration.
- Which murmur characteristic best identifies the holosystolic murmur of mitral regurgitation?
- A blowing murmur heard best at the apex radiating to the axilla
- A harsh crescendo-decrescendo murmur at the right upper sternal border
- An early diastolic decrescendo murmur along the left sternal border
- A continuous machine-like murmur below the left clavicle
Correct answer: A blowing murmur heard best at the apex radiating to the axilla
A blowing holosystolic murmur heard best at the apex and radiating to the axilla best identifies mitral regurgitation, reflecting retrograde flow from the left ventricle into the left atrium throughout systole. The apical location with axillary radiation is characteristic. A harsh crescendo-decrescendo murmur at the right upper sternal border describes aortic stenosis, an early diastolic decrescendo murmur describes aortic regurgitation, and a continuous machine-like murmur below the clavicle describes a patent ductus arteriosus.
- During cardiac auscultation, a clinician notes that a systolic murmur becomes louder during the strain phase of the Valsalva maneuver and softer with squatting. Which condition is most consistent with this dynamic behavior?
- Aortic stenosis
- Ventricular septal defect
- Hypertrophic obstructive cardiomyopathy
- Mitral stenosis
Correct answer: Hypertrophic obstructive cardiomyopathy
Hypertrophic obstructive cardiomyopathy is most consistent because its outflow murmur intensifies with maneuvers that reduce preload, such as the Valsalva strain phase and standing, and softens with squatting that increases ventricular volume. Decreased chamber size worsens the dynamic obstruction. In contrast, the murmur of aortic stenosis typically softens with reduced preload, a ventricular septal defect murmur decreases with Valsalva, and mitral stenosis produces a diastolic rather than systolic murmur.
- A 30-year-old woman has an early diastolic decrescendo murmur heard best at the left sternal border when she leans forward and exhales. She also has a wide pulse pressure and bounding peripheral pulses. Which valvular lesion best explains these findings?
- Aortic regurgitation
- Mitral stenosis
- Tricuspid stenosis
- Aortic stenosis
Correct answer: Aortic regurgitation
Aortic regurgitation best explains these findings because an early diastolic decrescendo murmur along the left sternal border, a wide pulse pressure, and bounding pulses result from regurgitant flow back into the left ventricle during diastole. The large stroke volume and rapid runoff produce the peripheral signs. Mitral stenosis causes a diastolic rumble at the apex with a narrow pulse pressure, tricuspid stenosis is a rare right-sided diastolic murmur, and aortic stenosis produces a systolic murmur.
- A 26-year-old woman who emigrated from a region with limited health care presents with exertional dyspnea and a low-pitched mid-diastolic rumbling murmur at the apex with an opening snap, best heard in the left lateral decubitus position. Which valvular disorder, often a sequela of rheumatic fever, is most likely?
- Aortic regurgitation
- Mitral stenosis
- Pulmonic regurgitation
- Mitral valve prolapse
Correct answer: Mitral stenosis
Mitral stenosis is most likely because a low-pitched mid-diastolic apical rumble with an opening snap, accentuated in the left lateral decubitus position, is the classic finding of a stenotic mitral valve, most commonly caused by rheumatic heart disease. The opening snap reflects the abrupt halt of the stiffened leaflet. Aortic regurgitation and pulmonic regurgitation produce diastolic murmurs at the sternal borders, and mitral valve prolapse produces a midsystolic click and late systolic murmur.
- A 24-year-old man with no prior cardiac history undergoes a routine examination and is found to have a soft, short, midsystolic murmur at the left lower sternal border that disappears when he sits up, with normal heart sounds and no other findings. He is asymptomatic. What is the most appropriate next step?
- Urgent valve replacement surgery
- Initiation of lifelong anticoagulation
- Reassurance, as this is most consistent with a benign flow murmur
- Immediate cardiac catheterization
Correct answer: Reassurance, as this is most consistent with a benign flow murmur
Reassurance is most appropriate because a soft, short, position-dependent midsystolic murmur with otherwise normal examination findings in an asymptomatic young person is characteristic of a benign innocent flow murmur that requires no intervention. The absence of diastolic components, extra sounds, or symptoms supports this. Valve replacement, anticoagulation, and cardiac catheterization are aggressive and unnecessary in the absence of any features suggesting structural valvular disease.
- A 58-year-old man with stable coronary artery disease describes predictable substernal chest pressure that occurs with climbing two flights of stairs and resolves within minutes of rest. Which term best characterizes this symptom pattern?
- Stable angina pectoris
- Unstable angina
- Acute pericarditis
- Aortic dissection
Correct answer: Stable angina pectoris
Stable angina pectoris best characterizes this pattern because chest discomfort that is reproducibly provoked by a consistent level of exertion and relieved promptly by rest reflects a fixed coronary stenosis limiting flow during increased demand. The predictability defines stability. Unstable angina occurs at rest or with a crescendo pattern, acute pericarditis causes sharp pleuritic pain often relieved by leaning forward, and aortic dissection produces severe tearing pain, none matching this exertional, predictable presentation.
- A 70-year-old woman is diagnosed with atrial fibrillation and has a mechanical mitral valve prosthesis. Which anticoagulant is the appropriate choice for stroke prevention in this specific situation?
- Apixaban
- Rivaroxaban
- Dabigatran
- Warfarin with a target INR range
Correct answer: Warfarin with a target INR range
Warfarin with a target INR range is the appropriate choice because patients with a mechanical heart valve require vitamin K antagonist therapy, as direct oral anticoagulants are contraindicated and have been shown to be inferior and harmful in this setting. Mechanical valves carry a high thrombotic risk that warfarin reliably manages. Apixaban, rivaroxaban, and dabigatran are all direct oral anticoagulants and must not be used in patients with mechanical prosthetic valves.
- A 55-year-old man develops an acute STEMI and is found to have complete occlusion of the right coronary artery. He becomes profoundly bradycardic with hypotension shortly after presentation. Which mechanism best explains the bradycardia in this inferior infarction?
- Ischemia of the sinoatrial or atrioventricular node and enhanced vagal tone
- Beta-agonist excess
- Hyperthyroidism
- Atrial fibrillation with rapid ventricular response
Correct answer: Ischemia of the sinoatrial or atrioventricular node and enhanced vagal tone
Ischemia of the sinoatrial or atrioventricular node and enhanced vagal tone best explains the bradycardia because the right coronary artery commonly supplies these nodes, and inferior infarctions frequently provoke heightened vagal activity, producing sinus bradycardia or atrioventricular block. This is a recognized complication of inferior STEMI. Beta-agonist excess and hyperthyroidism would cause tachycardia, and atrial fibrillation with rapid ventricular response is a tachyarrhythmia, none consistent with bradycardia.
- A 48-year-old woman presents with sharp, pleuritic chest pain that improves when she leans forward and worsens when she lies flat. Auscultation reveals a scratchy three-component friction rub, and her electrocardiogram shows diffuse ST-segment elevation with PR-segment depression. Which diagnosis is most likely?
- Acute pericarditis
- ST-elevation myocardial infarction
- Aortic stenosis
- Pulmonary embolism
Correct answer: Acute pericarditis
Acute pericarditis is most likely because positional pleuritic chest pain relieved by sitting forward, a three-component friction rub, and diffuse ST elevation with PR depression are the classic features of pericardial inflammation. The widespread rather than territorial electrocardiographic changes distinguish it from infarction. A STEMI causes ST elevation confined to a coronary territory with reciprocal changes, aortic stenosis produces exertional symptoms with a systolic murmur, and pulmonary embolism typically lacks a friction rub and diffuse ST elevation.
- A 62-year-old man with heart failure and a reduced ejection fraction is started on an angiotensin receptor-neprilysin inhibitor. Which prior medication must be stopped, with an adequate washout period, before this agent is initiated to avoid a dangerous interaction?
- A beta-blocker
- An ACE inhibitor, because of the risk of angioedema
- A statin
- Aspirin
Correct answer: An ACE inhibitor, because of the risk of angioedema
An ACE inhibitor must be stopped with an adequate washout because combining it with a neprilysin inhibitor markedly increases the risk of angioedema through additive effects on bradykinin metabolism. A washout period of at least 36 hours is required before switching. Beta-blockers, statins, and aspirin can be safely continued and do not produce this specific interaction, so they do not need to be discontinued before starting the angiotensin receptor-neprilysin inhibitor.
- A 72-year-old woman presents with exertional dyspnea and signs of heart failure, but echocardiography reveals a preserved ejection fraction of 60 percent with left ventricular hypertrophy and impaired relaxation. Which underlying physiologic abnormality best explains her heart failure?
- Severe systolic pump failure
- Diastolic dysfunction with impaired ventricular filling
- Acute valve rupture
- High-output failure from anemia
Correct answer: Diastolic dysfunction with impaired ventricular filling
Diastolic dysfunction with impaired ventricular filling best explains her presentation because heart failure with preserved ejection fraction arises when a stiff, hypertrophied ventricle relaxes poorly, raising filling pressures despite normal contractility. The preserved ejection fraction with hypertrophy and impaired relaxation is characteristic. Severe systolic pump failure would lower the ejection fraction, acute valve rupture causes sudden severe symptoms with murmurs, and high-output failure from anemia would show a hyperdynamic circulation rather than impaired relaxation.
- A patient with severe symptomatic aortic stenosis is incidentally found to also have angina. Coronary angiography before valve replacement is most important to accomplish which goal?
- Confirm the diagnosis of aortic stenosis
- Measure the aortic valve area
- Identify significant coronary artery disease that may require revascularization at the time of valve surgery
- Assess for mitral valve prolapse
Correct answer: Identify significant coronary artery disease that may require revascularization at the time of valve surgery
Identifying significant coronary artery disease that may require concomitant revascularization is the most important goal of preoperative coronary angiography, because aortic stenosis frequently coexists with coronary disease and detecting it allows combined valve and bypass intervention to be planned. This optimizes the surgical strategy. The diagnosis and valve area are established by echocardiography, and assessment for mitral valve prolapse is not the purpose of coronary angiography in this setting.
- A 50-year-old man with resistant hypertension is found to have hypokalemia and metabolic alkalosis. His aldosterone is elevated with a suppressed renin level. Which secondary cause of hypertension is most likely?
- Primary hyperaldosteronism
- Pheochromocytoma
- Renal artery stenosis with high renin
- Cushing syndrome from exogenous steroids
Correct answer: Primary hyperaldosteronism
Primary hyperaldosteronism is most likely because resistant hypertension with hypokalemia, metabolic alkalosis, an elevated aldosterone level, and a suppressed renin reflects autonomous aldosterone secretion that drives sodium retention and potassium loss. The high aldosterone-to-renin ratio is the diagnostic clue. Pheochromocytoma produces catecholamine excess with paroxysmal symptoms, renal artery stenosis raises renin rather than suppressing it, and Cushing syndrome causes a distinct constellation including central obesity and glucose intolerance.
- A 64-year-old man with persistent atrial fibrillation despite two antiarrhythmic drugs continues to have symptomatic palpitations and reduced exercise tolerance. He prefers a rhythm-control approach. Which intervention offers a durable nonpharmacologic option to maintain sinus rhythm?
- Permanent pacemaker without ablation
- Catheter ablation with pulmonary vein isolation
- Lifelong aspirin therapy
- An implantable loop recorder
Correct answer: Catheter ablation with pulmonary vein isolation
Catheter ablation with pulmonary vein isolation offers a durable nonpharmacologic option because the pulmonary veins are the dominant source of triggers initiating atrial fibrillation, and electrically isolating them can maintain sinus rhythm when drug therapy fails or is not tolerated. It is reasonable for symptomatic drug-refractory patients. A pacemaker alone does not prevent the arrhythmia, aspirin neither controls rhythm nor reliably prevents stroke, and a loop recorder only monitors rhythm without treating it.
- A 67-year-old man with acute coronary syndrome undergoes coronary stenting. Which antithrombotic regimen is standard immediately after placement of a drug-eluting stent?
- Aspirin monotherapy only
- Warfarin monotherapy
- Dual antiplatelet therapy with aspirin and a P2Y12 inhibitor
- No antithrombotic therapy
Correct answer: Dual antiplatelet therapy with aspirin and a P2Y12 inhibitor
Dual antiplatelet therapy with aspirin and a P2Y12 inhibitor such as clopidogrel, ticagrelor, or prasugrel is standard after drug-eluting stent placement because it prevents stent thrombosis during endothelialization while reducing recurrent ischemic events. Both agents are needed for adequate platelet inhibition. Aspirin alone is insufficient to prevent stent thrombosis, warfarin targets a different pathway and does not replace antiplatelet therapy here, and withholding antithrombotic therapy would risk catastrophic stent thrombosis.
- A 75-year-old woman with severe aortic stenosis reports increasing exertional chest pain and a near-syncopal episode. Why is the onset of these symptoms a critical prognostic turning point in aortic stenosis?
- Symptomatic severe aortic stenosis carries a sharply increased mortality without valve replacement
- Symptoms indicate the stenosis has spontaneously resolved
- Symptoms reliably respond to long-term medical therapy
- Symptoms predict a benign course requiring only observation
Correct answer: Symptomatic severe aortic stenosis carries a sharply increased mortality without valve replacement
Symptomatic severe aortic stenosis carries a sharply increased mortality without valve replacement, which is why the appearance of angina, syncope, or heart failure marks a critical turning point that mandates referral for intervention. Survival declines markedly once symptoms develop. The symptoms do not indicate resolution of the stenosis, no medical therapy reverses the fixed obstruction, and continued observation alone after symptom onset is associated with a poor prognosis.
- A 59-year-old man with hypertension and heart failure with reduced ejection fraction is started on an SGLT2 inhibitor. Which benefit of this medication class is most relevant to his heart failure management?
- Reduction in heart failure hospitalizations and cardiovascular death
- Direct lowering of low-density lipoprotein cholesterol
- Restoration of sinus rhythm in atrial fibrillation
- Reversal of established valvular stenosis
Correct answer: Reduction in heart failure hospitalizations and cardiovascular death
Reduction in heart failure hospitalizations and cardiovascular death is the most relevant benefit, as SGLT2 inhibitors improve outcomes in heart failure with reduced ejection fraction regardless of diabetes status and are now a foundational therapy. Their benefit is independent of glucose lowering. These agents do not directly lower cholesterol, do not restore sinus rhythm in atrial fibrillation, and cannot reverse fixed valvular stenosis, so those mechanisms are not why they are used in heart failure.
- A 61-year-old man with newly diagnosed atrial fibrillation of uncertain duration is hemodynamically stable, and the team plans elective cardioversion. He has not been anticoagulated. Which approach minimizes the risk of a thromboembolic stroke at the time of cardioversion?
- Cardiovert immediately without any imaging or anticoagulation
- Give a single dose of aspirin just before the procedure
- Perform transesophageal echocardiography to exclude a left atrial thrombus, or anticoagulate for at least three weeks beforehand
- Delay cardioversion indefinitely and rely on rate control alone
Correct answer: Perform transesophageal echocardiography to exclude a left atrial thrombus, or anticoagulate for at least three weeks beforehand
Performing transesophageal echocardiography to exclude a left atrial thrombus, or anticoagulating for at least three weeks beforehand, minimizes thromboembolic risk because restoring sinus rhythm can dislodge an atrial clot if present. These strategies ensure the atrium is free of thrombus before cardioversion. Immediate cardioversion without imaging or anticoagulation in atrial fibrillation of uncertain duration risks stroke, a single aspirin dose is inadequate, and indefinite delay is unnecessary when safe pathways exist.
- A 30-year-old woman with a connective tissue disorder is found to have a dilated aortic root on echocardiography and a soft early diastolic murmur. Which mechanism best explains how aortic root dilation can produce aortic regurgitation?
- Dilation stretches the valve annulus so the leaflets fail to coapt during diastole
- Dilation fuses the aortic valve commissures
- Dilation calcifies and stiffens the leaflets
- Dilation thickens the mitral leaflets
Correct answer: Dilation stretches the valve annulus so the leaflets fail to coapt during diastole
Dilation stretching the valve annulus so the leaflets fail to coapt during diastole best explains aortic regurgitation from root disease, because annular enlargement separates otherwise normal cusps and allows backward flow. This is a common mechanism in connective tissue disorders affecting the aorta. Commissural fusion describes stenosis from rheumatic disease, leaflet calcification causes stenosis, and thickening of the mitral leaflets is unrelated to the aortic valve.
- A 55-year-old man with hypertension is started on lisinopril. Two weeks later he develops a persistent dry cough without dyspnea or wheezing. His blood pressure is well controlled. What is the most appropriate management of this side effect?
- Add an inhaled corticosteroid
- Switch to an angiotensin receptor blocker
- Begin a course of antibiotics
- Discontinue all antihypertensive therapy
Correct answer: Switch to an angiotensin receptor blocker
Switching to an angiotensin receptor blocker is most appropriate because the dry cough is a well-known class effect of ACE inhibitors caused by bradykinin accumulation, and angiotensin receptor blockers provide comparable blood pressure control without provoking the cough. This preserves effective therapy. An inhaled corticosteroid does not address the drug mechanism, antibiotics are unnecessary in the absence of infection, and stopping all antihypertensive therapy would leave the hypertension untreated.
- A 65-year-old man with heart failure and reduced ejection fraction is in sinus rhythm with a resting heart rate of 78 beats per minute despite a maximally tolerated beta-blocker, and he remains symptomatic. Which medication selectively slows the sinus node rate to provide additional benefit in this setting?
- Ivabradine
- Amlodipine
- Hydralazine
- Furosemide
Correct answer: Ivabradine
Ivabradine is correct because it selectively inhibits the sinoatrial node funny current to lower heart rate in patients in sinus rhythm who remain symptomatic with an elevated resting rate despite a maximally tolerated beta-blocker, reducing heart failure hospitalizations. It acts only on the rate, not contractility. Amlodipine does not improve heart failure outcomes, hydralazine is a vasodilator without selective rate effects, and furosemide relieves congestion but does not slow the sinus node.
- A 58-year-old man with a STEMI is found to have a new harsh holosystolic murmur and acute pulmonary edema several days after his infarction. Echocardiography shows a left-to-right shunt at the ventricular level. Which mechanical complication of myocardial infarction has most likely occurred?
- Ventricular septal rupture
- Pericardial effusion without tamponade
- Aortic stenosis
- Sinus node dysfunction
Correct answer: Ventricular septal rupture
Ventricular septal rupture has most likely occurred because a new harsh holosystolic murmur with acute hemodynamic deterioration and a demonstrable left-to-right shunt days after infarction reflects rupture of the necrotic septum. This is a life-threatening mechanical complication requiring urgent intervention. A simple pericardial effusion would not cause a shunt murmur, aortic stenosis is a chronic process unrelated to acute infarction timing, and sinus node dysfunction causes bradyarrhythmias rather than a shunt.
- A 76-year-old woman with atrial fibrillation on a direct oral anticoagulant has a high bleeding risk and recurrent gastrointestinal hemorrhage that precludes continued anticoagulation, yet she has a high stroke risk. Which intervention provides an alternative means of stroke prevention?
- Permanent pacemaker implantation
- Coronary stenting
- Aortic valve replacement
- Left atrial appendage occlusion
Correct answer: Left atrial appendage occlusion
Left atrial appendage occlusion provides an alternative means of stroke prevention because most thrombi in nonvalvular atrial fibrillation form in the left atrial appendage, and mechanically sealing it reduces embolic stroke risk in patients who cannot tolerate long-term anticoagulation. It addresses the anatomic source of clots. A pacemaker treats bradyarrhythmias, coronary stenting addresses coronary disease, and aortic valve replacement treats valvular stenosis, none of which prevent atrial appendage thromboembolism.
- A 68-year-old woman with diabetes presents with sudden dyspnea, fatigue, and nausea but no chest pain. Her electrocardiogram shows new ST-segment depressions and troponin is elevated. Which point about acute coronary syndrome presentation does this case best illustrate?
- Acute coronary syndrome never occurs without chest pain
- Troponin elevation excludes a cardiac cause
- Women, older adults, and patients with diabetes may present with atypical or anginal-equivalent symptoms rather than classic chest pain
- Dyspnea is unrelated to myocardial ischemia
Correct answer: Women, older adults, and patients with diabetes may present with atypical or anginal-equivalent symptoms rather than classic chest pain
This case illustrates that women, older adults, and patients with diabetes may present with atypical or anginal-equivalent symptoms such as dyspnea, fatigue, or nausea rather than classic chest pain, which can delay recognition of acute coronary syndrome. Maintaining a high index of suspicion is essential. Acute coronary syndrome can clearly occur without chest pain, troponin elevation supports rather than excludes myocardial injury, and dyspnea can be a direct ischemic equivalent.
- A 50-year-old asymptomatic man is found to have a bicuspid aortic valve on echocardiography performed for a systolic ejection murmur and an ejection click. Beyond valve dysfunction, which associated cardiovascular complication warrants ongoing surveillance imaging in this condition?
- Dilation of the ascending aorta and aneurysm formation
- Pulmonary vein stenosis
- Atrial septal defect closure
- Coronary artery spasm
Correct answer: Dilation of the ascending aorta and aneurysm formation
Dilation of the ascending aorta and aneurysm formation warrants ongoing surveillance because a bicuspid aortic valve is associated with an underlying aortopathy that predisposes to progressive ascending aortic enlargement and dissection independent of valve severity. Periodic imaging monitors the aortic dimensions. Pulmonary vein stenosis, atrial septal defect closure, and coronary artery spasm are not the characteristic associated complications of a bicuspid aortic valve requiring routine aortic surveillance.
- A 64-year-old man develops a wide-complex tachycardia at 180 beats per minute with hypotension and chest pain three days after an anterior myocardial infarction. He has a pulse. The rhythm is regular with a uniform QRS morphology. Which arrhythmia is most likely and what is the immediate treatment?
- Sinus tachycardia treated with reassurance
- Atrial fibrillation treated with digoxin
- Sustained monomorphic ventricular tachycardia treated with synchronized cardioversion
- First-degree atrioventricular block treated with a pacemaker
Correct answer: Sustained monomorphic ventricular tachycardia treated with synchronized cardioversion
Sustained monomorphic ventricular tachycardia treated with synchronized cardioversion is most likely because a regular wide-complex tachycardia with a uniform QRS in a patient with recent infarction and hemodynamic compromise represents a scar-related reentrant ventricular arrhythmia requiring prompt electrical cardioversion. The instability mandates rapid rhythm termination. Sinus tachycardia would not be this fast and regular with wide complexes, atrial fibrillation is irregular, and first-degree atrioventricular block is not a tachyarrhythmia.
- A 60-year-old woman has chronic severe primary mitral regurgitation. She is asymptomatic but serial echocardiograms now show a left ventricular ejection fraction declining to 58 percent and an enlarging left ventricular end-systolic dimension. What is the most appropriate management?
- Continue observation until severe symptoms develop
- Refer for mitral valve surgery, preferably repair
- Start long-term antibiotics
- Begin chronic anticoagulation alone
Correct answer: Refer for mitral valve surgery, preferably repair
Referral for mitral valve surgery, preferably repair, is most appropriate because in chronic severe primary mitral regurgitation, declining ejection fraction toward the lower threshold and progressive left ventricular enlargement are objective indications for intervention even before severe symptoms appear. Early repair preserves ventricular function. Waiting for severe symptoms risks irreversible dysfunction, antibiotics do not treat the regurgitation, and anticoagulation alone does not address the valvular volume overload.
- A 72-year-old man with longstanding hypertension and an ejection fraction of 30 percent is at elevated risk of sudden cardiac death despite optimized guideline-directed medical therapy. Which device is most appropriate for primary prevention of sudden death in this setting?
- A loop recorder
- An intra-aortic balloon pump
- A peripheral arterial stent
- An implantable cardioverter-defibrillator
Correct answer: An implantable cardioverter-defibrillator
An implantable cardioverter-defibrillator is most appropriate because patients with a markedly reduced ejection fraction who remain at high risk of ventricular arrhythmias despite optimal medical therapy benefit from a device that detects and terminates lethal arrhythmias, providing primary prevention of sudden cardiac death. It directly aborts ventricular fibrillation or tachycardia. A loop recorder only monitors, an intra-aortic balloon pump is temporary mechanical support, and a peripheral arterial stent treats vascular disease, not arrhythmic death.
- A 45-year-old man with hypertension reports taking his amlodipine inconsistently and continues to use a daily nonsteroidal anti-inflammatory drug for chronic back pain. His blood pressure remains elevated. Besides reinforcing adherence, which modifiable factor is most likely contributing to his poor control?
- Daily aspirin lowering blood pressure
- Regular nonsteroidal anti-inflammatory drug use raising blood pressure
- Excess thyroid hormone replacement
- Use of an angiotensin receptor blocker
Correct answer: Regular nonsteroidal anti-inflammatory drug use raising blood pressure
Regular nonsteroidal anti-inflammatory drug use is most likely contributing because these agents cause sodium retention and blunt the effect of many antihypertensives, raising blood pressure and undermining control. Identifying and addressing this interfering medication is an important step in resistant or poorly controlled hypertension. Aspirin does not meaningfully raise blood pressure, the scenario does not describe thyroid hormone use, and an angiotensin receptor blocker would help rather than worsen control.
- A 58-year-old woman presents with sudden severe chest pain after extreme emotional stress. Her electrocardiogram shows anterior ST changes and troponin is mildly elevated, but coronary angiography reveals no obstructive disease, and the left ventricle shows apical ballooning with a hyperdynamic base. Which condition best fits this presentation?
- Acute ST-elevation myocardial infarction from plaque rupture
- Severe aortic stenosis
- Stress (takotsubo) cardiomyopathy
- Chronic stable angina
Correct answer: Stress (takotsubo) cardiomyopathy
Stress (takotsubo) cardiomyopathy best fits because an acute presentation after intense emotional stress with transient apical ballooning, modest troponin elevation, and nonobstructive coronary arteries is characteristic of this catecholamine-mediated reversible left ventricular dysfunction. The wall-motion pattern with a hyperdynamic base is classic. Plaque-rupture STEMI would show obstructive coronary disease, aortic stenosis produces a fixed outflow murmur with exertional symptoms, and chronic stable angina does not cause acute apical ballooning.
- A 35-year-old previously healthy man dies suddenly during exertion, and family history reveals several relatives with sudden death. Autopsy shows asymmetric septal hypertrophy. In living relatives, which auscultatory maneuver would increase the intensity of the associated outflow murmur?
- Passive leg raising, which increases preload
- Sustained handgrip, which increases afterload
- Lying supine, which increases venous return
- Standing from a squatting position, which decreases preload
Correct answer: Standing from a squatting position, which decreases preload
Standing from a squatting position would increase the murmur intensity because reducing preload decreases left ventricular volume, worsening the dynamic outflow obstruction of hypertrophic cardiomyopathy and making the murmur louder. Maneuvers that shrink the chamber accentuate the murmur. Passive leg raising and lying supine increase venous return and ventricular volume, softening the murmur, and sustained handgrip raises afterload, which also tends to decrease the obstruction and murmur intensity.
- A 70-year-old man with heart failure and reduced ejection fraction has gout and chronic kidney disease. He develops worsening renal function and hyperkalemia after his mineralocorticoid receptor antagonist dose was increased. What is the most appropriate response?
- Double the mineralocorticoid receptor antagonist dose
- Reduce or hold the mineralocorticoid receptor antagonist and recheck potassium and renal function
- Add a potassium supplement
- Stop the beta-blocker immediately
Correct answer: Reduce or hold the mineralocorticoid receptor antagonist and recheck potassium and renal function
Reducing or holding the mineralocorticoid receptor antagonist and rechecking potassium and renal function is most appropriate because these agents can cause hyperkalemia and worsening renal function, especially in chronic kidney disease, requiring dose adjustment and close monitoring. Safety depends on tracking these laboratory values. Increasing the dose or adding potassium would worsen the hyperkalemia, and stopping the beta-blocker is unrelated to the potassium problem and would remove a beneficial heart failure therapy.
- A 62-year-old man presents with an acute STEMI and is given aspirin, a P2Y12 inhibitor, and an anticoagulant before transfer for percutaneous coronary intervention. Which is the primary rationale for early dual antiplatelet therapy at the time of presentation?
- To lower cholesterol acutely
- To inhibit platelet aggregation at the site of the ruptured plaque and reduce thrombus propagation
- To convert the rhythm to sinus
- To dilate the coronary arteries directly
Correct answer: To inhibit platelet aggregation at the site of the ruptured plaque and reduce thrombus propagation
Inhibiting platelet aggregation at the site of the ruptured plaque and reducing thrombus propagation is the primary rationale, because acute coronary syndrome results from platelet-rich thrombus forming over a disrupted plaque, and early antiplatelet therapy limits clot growth and improves outcomes. This is foundational acute management. Antiplatelet agents do not acutely lower cholesterol, do not convert cardiac rhythm, and do not directly dilate the coronary arteries.
- A 55-year-old man with newly detected atrial fibrillation has a CHA2DS2-VASc score of 1 attributable solely to hypertension. He has no other risk factors. Which consideration best guides the decision about anticoagulation in this patient?
- Anticoagulation is absolutely contraindicated at any score
- All patients with a score of 1 require lifelong warfarin
- Anticoagulation may be considered, weighing the modest stroke risk against bleeding risk and patient preference
- Aspirin is clearly superior to anticoagulation in all cases
Correct answer: Anticoagulation may be considered, weighing the modest stroke risk against bleeding risk and patient preference
Anticoagulation may be considered while weighing the modest stroke risk against bleeding risk and patient preference, because a CHA2DS2-VASc score of 1 represents an intermediate risk where the decision is individualized rather than automatic. Shared decision-making is appropriate at this threshold. Anticoagulation is not categorically contraindicated, a score of 1 does not mandate lifelong warfarin for everyone, and aspirin is not clearly superior to oral anticoagulants for stroke prevention in atrial fibrillation.
- A 48-year-old woman with chronic severe aortic regurgitation remains asymptomatic. Which medication class may be used to reduce afterload and slow progression in selected patients while monitoring for the need for valve surgery?
- Vasodilators such as ACE inhibitors or dihydropyridine calcium channel blockers in those with hypertension
- Nondihydropyridine calcium channel blockers to slow the heart rate
- Beta-blockers to maximize the diastolic filling time
- Loop diuretics as definitive therapy
Correct answer: Vasodilators such as ACE inhibitors or dihydropyridine calcium channel blockers in those with hypertension
Vasodilators such as ACE inhibitors or dihydropyridine calcium channel blockers are reasonable in patients with chronic aortic regurgitation who also have hypertension, because reducing afterload eases the regurgitant burden on the left ventricle. They help manage coexisting hypertension while surveillance continues. Slowing the heart rate excessively can be harmful in aortic regurgitation because a longer diastole increases regurgitant volume, and loop diuretics treat congestion rather than serving as definitive therapy for the valve lesion.
- A 66-year-old man with heart failure and reduced ejection fraction is counseled about lifestyle measures. Which dietary recommendation most directly helps reduce fluid retention and decompensation episodes?
- A high-sodium diet to maintain blood pressure
- Unrestricted fluid intake regardless of symptoms
- A high-protein, high-sodium supplement regimen
- Dietary sodium restriction
Correct answer: Dietary sodium restriction
Dietary sodium restriction most directly helps because limiting sodium reduces water retention, lowering the risk of congestion and acute decompensation in heart failure. It complements diuretic and neurohormonal therapy. A high-sodium diet promotes fluid retention and worsens congestion, unrestricted fluid intake can precipitate volume overload in advanced disease, and high-sodium supplements would directly counteract the goal of reducing fluid accumulation.
- A 73-year-old man undergoing evaluation of a systolic murmur is found on echocardiography to have severe low-flow, low-gradient aortic stenosis with a reduced ejection fraction. Which test helps distinguish true severe stenosis from pseudosevere stenosis in this challenging scenario?
- A 24-hour ambulatory blood pressure monitor
- A treadmill exercise tolerance test alone
- Low-dose dobutamine stress echocardiography
- A fasting lipid panel
Correct answer: Low-dose dobutamine stress echocardiography
Low-dose dobutamine stress echocardiography helps distinguish true severe aortic stenosis from pseudosevere stenosis because increasing contractility raises flow across the valve, allowing assessment of whether the gradient and valve area reflect genuinely severe obstruction or merely low cardiac output. This clarifies management in low-flow, low-gradient disease. Ambulatory blood pressure monitoring, a standard exercise test alone, and a lipid panel do not resolve this specific hemodynamic question.
- A 60-year-old man with stable coronary artery disease asks why he should continue his statin even though his cholesterol is now at goal. Which mechanism beyond cholesterol lowering best explains the statin's benefit in coronary disease?
- Direct restoration of normal sinus rhythm
- Reversal of established valvular calcification
- Immediate dissolution of existing coronary thrombus
- Stabilization of atherosclerotic plaque, reducing the risk of plaque rupture and acute events
Correct answer: Stabilization of atherosclerotic plaque, reducing the risk of plaque rupture and acute events
Stabilization of atherosclerotic plaque, reducing the risk of plaque rupture and acute events, best explains the continued benefit, because statins exert pleiotropic effects that make plaques less prone to rupture in addition to lowering cholesterol. This lowers the chance of future acute coronary syndromes. Statins do not restore sinus rhythm, do not reverse valvular calcification, and do not acutely dissolve coronary thrombus, so those mechanisms do not account for ongoing therapy.
- A 50-year-old man is incidentally noted to have a continuous machine-like murmur heard below the left clavicle that is present in both systole and diastole. Which lesion classically produces this type of continuous murmur?
- Patent ductus arteriosus
- Aortic stenosis
- Mitral stenosis
- Tricuspid regurgitation
Correct answer: Patent ductus arteriosus
A patent ductus arteriosus classically produces a continuous machine-like murmur below the left clavicle because persistent flow from the higher-pressure aorta into the pulmonary artery occurs throughout both systole and diastole. The uninterrupted pressure gradient generates the continuous quality. Aortic stenosis and tricuspid regurgitation produce systolic murmurs, and mitral stenosis produces a diastolic murmur, none of which span the entire cardiac cycle as a continuous murmur.
- A 68-year-old woman with atrial fibrillation and rate control on a beta-blocker now reports fatigue and exertional symptoms, and ambulatory monitoring shows frequent pauses and bradycardia at rest. Which underlying condition is most likely, given both tachyarrhythmia and bradyarrhythmia?
- Wolff-Parkinson-White syndrome
- Isolated first-degree atrioventricular block
- Sick sinus syndrome (tachy-brady syndrome)
- Acute pericarditis
Correct answer: Sick sinus syndrome (tachy-brady syndrome)
Sick sinus syndrome, also called tachy-brady syndrome, is most likely because alternating episodes of atrial fibrillation with rapid rates and symptomatic sinus pauses or bradycardia reflect sinoatrial node dysfunction, which often necessitates pacemaker placement if rate-controlling drugs worsen the bradycardia. The combination of tachyarrhythmia and bradyarrhythmia is characteristic. Wolff-Parkinson-White involves an accessory pathway, isolated first-degree block does not cause pauses, and pericarditis does not produce this rhythm pattern.
- A 64-year-old man recovering from a large anterior myocardial infarction is found two months later to have a persistent ST-segment elevation on electrocardiography and a dyskinetic bulge of the left ventricular wall on echocardiography, along with heart failure symptoms. Which late complication has most likely developed?
- Acute stent thrombosis
- New aortic stenosis
- Constrictive pericarditis
- Left ventricular aneurysm
Correct answer: Left ventricular aneurysm
A left ventricular aneurysm has most likely developed because persistent ST-segment elevation weeks after infarction together with a dyskinetic outpouching of the ventricular wall and heart failure is characteristic of aneurysm formation in infarcted, scarred myocardium. The akinetic or dyskinetic segment impairs pump function. Acute stent thrombosis presents abruptly with recurrent ischemia, new aortic stenosis is unrelated to infarct scarring, and constrictive pericarditis causes filling impairment without a dyskinetic ventricular bulge.
- A 57-year-old man with hypertension and an ejection fraction of 35 percent who is intolerant of both ACE inhibitors and angiotensin receptor blockers because of recurrent angioedema needs additional therapy. Which vasodilator combination has proven mortality benefit in heart failure, particularly studied in self-identified Black patients?
- Amlodipine combined with a beta-blocker
- Verapamil combined with digoxin
- Doxazosin combined with a thiazide
- Hydralazine combined with isosorbide dinitrate
Correct answer: Hydralazine combined with isosorbide dinitrate
Hydralazine combined with isosorbide dinitrate has proven mortality benefit in heart failure with reduced ejection fraction and is especially supported in self-identified Black patients and in those who cannot tolerate renin-angiotensin system blockers. The combination provides balanced arterial and venous vasodilation. Amlodipine with a beta-blocker, verapamil with digoxin, and doxazosin with a thiazide have not demonstrated this survival benefit in heart failure.
- A 49-year-old woman with resistant hypertension on three agents including a diuretic remains above goal. Loud abdominal bruits are noted, and she had a sharp rise in creatinine after starting an ACE inhibitor. Which secondary cause should be suspected?
- Primary hyperaldosteronism
- Obstructive sleep apnea alone
- Pheochromocytoma
- Renal artery stenosis
Correct answer: Renal artery stenosis
Renal artery stenosis should be suspected because resistant hypertension with abdominal bruits and a marked rise in creatinine after introducing an ACE inhibitor suggests reduced renal perfusion that depends on angiotensin-mediated efferent arteriolar tone. Blocking that mechanism unmasks the impaired perfusion. Primary hyperaldosteronism typically causes hypokalemia rather than this creatinine response, obstructive sleep apnea contributes to hypertension without the creatinine clue, and pheochromocytoma presents with paroxysmal catecholamine symptoms.
- A 70-year-old man with chronic heart failure and reduced ejection fraction has been on digoxin and presents with nausea, visual disturbances described as yellow-green halos, and a new bradyarrhythmia. His renal function has recently declined. Which problem is most likely responsible?
- Acute coronary syndrome
- Beta-blocker overdose
- Digoxin toxicity
- Hypertensive emergency
Correct answer: Digoxin toxicity
Digoxin toxicity is most likely because nausea, yellow-green visual halos, and bradyarrhythmias in a patient on digoxin, particularly with worsening renal clearance that raises drug levels, are classic features of toxicity. Recognizing this triad prompts level measurement and management. Acute coronary syndrome would present with ischemic symptoms and electrocardiographic changes of ischemia, beta-blocker overdose would not cause the visual halos, and a hypertensive emergency involves severely elevated blood pressure with target-organ damage.
- A 39-year-old nurse who has worn latex examination gloves for years develops itching, redness, and a few hives on both hands within minutes of donning a fresh pair, and the wheals fade within an hour of removing the gloves. Patch testing of the back is negative. Which type of contact reaction does this rapid, glove-shaped response represent?
- Delayed allergic contact dermatitis to rubber accelerators
- Immediate IgE-mediated contact urticaria to latex protein
- Irritant contact dermatitis from glove powder
- Photoallergic contact dermatitis
Correct answer: Immediate IgE-mediated contact urticaria to latex protein
Immediate IgE-mediated contact urticaria to natural rubber latex protein is represented because wheals and itching that appear within minutes of contact and resolve within an hour reflect a type I, antibody-mediated reaction rather than a delayed eczematous one. Delayed allergic contact dermatitis to rubber accelerators is a type IV reaction that produces eczema 24 to 72 hours later and would be picked up on patch testing, irritant dermatitis from powder causes gradual dryness and scaling rather than rapid hives, and photoallergic dermatitis requires ultraviolet light and sun-exposed skin, which does not fit a glove-covered, light-shielded distribution.
- A 5-year-old child has developed itchy, eczematous patches under a temporary black henna tattoo applied on vacation, and the eruption traces the exact outline of the design. The clinician suspects sensitization to an additive frequently mixed into black henna. Which contact allergen is the most likely culprit?
- Paraphenylenediamine
- Balsam of Peru
- Nickel sulfate
- Thimerosal
Correct answer: Paraphenylenediamine
Paraphenylenediamine is the most likely culprit because this hair-dye chemical is commonly added to black henna to darken it and is a potent sensitizer that produces allergic contact dermatitis precisely in the shape of the applied design. Balsam of Peru is a fragrance-related allergen tied to scented and flavored products rather than tattoo dye, nickel sulfate causes reactions where metal jewelry contacts skin, and thimerosal is a preservative associated with vaccines and contact lens solutions, none of which would reproduce the tattoo outline seen here.
- A 44-year-old man is seen for an itchy eczematous eruption thought to be allergic contact dermatitis, but standard patch testing is negative. The clinician suspects a substance that only causes a reaction when the involved skin is also exposed to sunlight. Which modified testing method is most appropriate to identify the responsible agent?
- Repeat standard patch testing with longer occlusion
- Serum specific IgE panel for environmental allergens
- Photopatch testing, applying duplicate allergens and irradiating one set with ultraviolet light
- Skin prick testing with the suspected chemicals
Correct answer: Photopatch testing, applying duplicate allergens and irradiating one set with ultraviolet light
Photopatch testing is most appropriate because it applies the suspected allergens in duplicate and exposes only one set to ultraviolet light, so a reaction appearing solely on the irradiated side identifies a photoallergen that standard patch testing would miss. Simply repeating standard patch testing with longer occlusion still omits the required light exposure, serum specific IgE measures immediate hypersensitivity rather than delayed photoallergy, and skin prick testing likewise assesses immediate IgE-mediated reactions that are not the mechanism of photoallergic contact dermatitis.
- A 70-year-old woman on allopurinol for three weeks is admitted with fever, a tender confluent erythematous rash, oral and conjunctival erosions, and dusky skin that detaches over an estimated 35 percent of the body surface. The first and most important intervention specific to her drug reaction is which of the following?
- Immediate discontinuation of the offending drug
- Administration of prophylactic systemic antibiotics
- Application of silver sulfadiazine to all denuded areas
- Starting high-dose intravenous immunoglobulin before any other step
Correct answer: Immediate discontinuation of the offending drug
Immediate discontinuation of the offending drug, here allopurinol, is the first and most important intervention because in toxic epidermal necrolysis prompt withdrawal of the culprit is associated with improved survival and is the single action with the clearest mortality benefit. Prophylactic systemic antibiotics are not given routinely and can themselves trigger reactions, silver sulfadiazine is a sulfonamide that is generally avoided in sulfa-associated severe reactions, and although immunomodulatory therapies are debated, none take precedence over stopping the causative medication.
- A 33-year-old woman recovering from drug reaction with eosinophilia and systemic symptoms (DRESS) caused by an anticonvulsant is being counseled at discharge. Beyond avoiding the culprit drug, which long-term complication should she be specifically monitored for after the acute illness resolves?
- Permanent loss of skin pigment at the rash sites
- Autoimmune thyroid disease and other late autoimmune sequelae
- Chronic dermatophyte infection of the nails
- Development of basal cell carcinoma at involved areas
Correct answer: Autoimmune thyroid disease and other late autoimmune sequelae
Autoimmune thyroid disease and other late autoimmune sequelae should be specifically monitored for because DRESS is recognized to predispose to delayed autoimmune disorders, most notably autoimmune thyroiditis, which can appear weeks to months after recovery and warrants follow-up thyroid testing. Permanent depigmentation at rash sites is not a characteristic DRESS sequela, chronic nail dermatophyte infection is unrelated to the drug reaction, and basal cell carcinoma arises from cumulative ultraviolet damage rather than as a consequence of DRESS.
- A clinician is reviewing why certain patients are at markedly higher risk for severe cutaneous reactions to specific drugs. For which drug-reaction pairing is pre-prescription screening for a particular HLA allele recommended to reduce the risk of Stevens-Johnson syndrome and toxic epidermal necrolysis, especially in at-risk ancestries?
- Penicillin and HLA-DR4
- Carbamazepine and HLA-B*15:02
- Vancomycin and HLA-A2
- Metformin and HLA-DQ8
Correct answer: Carbamazepine and HLA-B*15:02
Carbamazepine and HLA-B*15:02 is the pairing for which screening is recommended because carriers of this allele, more common in several Asian populations, have a strongly elevated risk of carbamazepine-induced Stevens-Johnson syndrome and toxic epidermal necrolysis, so testing before prescribing can prevent these reactions. Penicillin allergy is not predicted by HLA-DR4, vancomycin reactions are not screened with HLA-A2, and metformin is not associated with HLA-DQ8-linked severe cutaneous reactions.
- A 35-year-old woman has a long-standing dark brown streak running the full length of one fingernail that has recently widened, with brown pigment now extending onto the adjacent nail fold and cuticle. Which evaluation is most appropriate given the concern these findings raise?
- Reassurance that pigmented nail bands are always benign
- Topical antifungal therapy for presumed onychomycosis
- Biopsy of the nail matrix to evaluate for subungual melanoma
- Trimming the nail short and observing for one year
Correct answer: Biopsy of the nail matrix to evaluate for subungual melanoma
Biopsy of the nail matrix to evaluate for subungual melanoma is most appropriate because a widening longitudinal pigmented band with extension of pigment onto the surrounding nail fold, known as the Hutchinson sign, is a red flag for melanoma of the nail unit and requires histologic diagnosis. Reassurance is unsafe because not all pigmented bands are benign, antifungal therapy treats fungal infection rather than a melanocytic lesion, and simply trimming and observing delays diagnosis of a potentially lethal cancer.
- A 55-year-old Black man is diagnosed with a melanoma on the sole of his foot, presenting as an irregular dark patch with an area of ulceration. Which melanoma subtype is most characteristic of this location and is the form most commonly seen in people with darker skin?
- Superficial spreading melanoma
- Lentigo maligna melanoma
- Nodular melanoma of the back
- Acral lentiginous melanoma
Correct answer: Acral lentiginous melanoma
Acral lentiginous melanoma is most characteristic because it arises on the palms, soles, and nail units and is the subtype most commonly diagnosed in individuals with darker skin, often presenting late as an irregular pigmented patch on the sole. Superficial spreading melanoma typically appears on the trunk and legs of lighter-skinned individuals, lentigo maligna melanoma develops on chronically sun-damaged facial skin of older adults, and nodular melanoma is a rapidly growing dome-shaped lesion rather than a sole-based macular lesion.
- A patient with a melanoma on the upper arm has the lesion definitively excised. The pathology report gives a Breslow thickness, and the surgeon explains that this number directly determines how wide a margin of normal skin must be removed around the scar. Which principle correctly links tumor thickness to the recommended wide local excision margin?
- Thicker melanomas require progressively wider excision margins
- Excision margins are the same regardless of Breslow thickness
- Thinner melanomas require the widest margins to prevent recurrence
- Margins are chosen solely by the diameter of the original lesion
Correct answer: Thicker melanomas require progressively wider excision margins
Thicker melanomas require progressively wider excision margins because the recommended width of wide local excision scales with Breslow depth, so in situ and very thin lesions need only narrow margins while thicker invasive tumors call for wider margins to reduce local recurrence. A fixed margin regardless of thickness is incorrect, the relationship is not inverted so that thin lesions need the widest margins, and margins are determined by histologic thickness rather than by the surface diameter of the original lesion.
- A 6-year-old boy has honey-colored crusted erosions around the nose and mouth that began as small blisters and have spread over a few days, and several classmates have similar lesions. He is afebrile and otherwise well. Which is the most appropriate management for this localized nonbullous impetigo?
- Oral antiviral therapy
- A topical antibiotic such as mupirocin
- A high-potency topical corticosteroid
- A topical antifungal cream
Correct answer: A topical antibiotic such as mupirocin
A topical antibiotic such as mupirocin is the most appropriate management because limited nonbullous impetigo, recognized by its honey-colored crusts and caused by staphylococci or streptococci, responds well to topical antibacterial therapy without the need for systemic treatment. An antiviral does not treat this bacterial infection, a topical corticosteroid is immunosuppressive and would worsen an active infection, and an antifungal addresses dermatophytes rather than the bacteria responsible for impetigo.
- A 30-year-old man presents with intense generalized itching that is worst at night, along with thin, wavy, grayish burrows and excoriated papules in the finger webs, wrists, and around the waistline. Several household members are also itching. Which treatment is the most appropriate first-line therapy for this infestation?
- Oral antihistamines alone
- A topical corticosteroid applied to the burrows
- Topical permethrin applied to the whole body, with treatment of close contacts
- An oral antibiotic for presumed bacterial folliculitis
Correct answer: Topical permethrin applied to the whole body, with treatment of close contacts
Topical permethrin applied from the neck down over the entire body, together with simultaneous treatment of close contacts and laundering of bedding and clothing, is the most appropriate first-line therapy because the nocturnal itching, web-space burrows, and household clustering are classic for scabies, which requires a scabicide and contact treatment to eradicate. Antihistamines may ease itch but do not kill the mite, a topical corticosteroid does not treat the infestation, and antibiotics address bacterial infection rather than the mite causing scabies.
- A 45-year-old woman from the Mediterranean region has multiple well-demarcated patches of complete pigment loss on the hands, around the mouth, and on the elbows, with no scale, atrophy, or symptoms, and the depigmented areas glow bright on examination with a Wood lamp. Which condition best explains this depigmentation, and what underlying association should be considered?
- Tinea versicolor, associated with humid climates
- Vitiligo, associated with other autoimmune conditions such as thyroid disease
- Postinflammatory hypopigmentation, associated with prior trauma only
- Pityriasis alba, associated with atopic dermatitis in children
Correct answer: Vitiligo, associated with other autoimmune conditions such as thyroid disease
Vitiligo best explains the findings because sharply demarcated patches of complete depigmentation that accentuate under a Wood lamp reflect autoimmune destruction of melanocytes, and it is associated with other autoimmune disorders, most commonly autoimmune thyroid disease, which should be screened for. Tinea versicolor produces fine scaling patches of altered, not absent, pigment with hyphae and spores on microscopy, postinflammatory hypopigmentation follows specific prior skin injury and is usually incomplete, and pityriasis alba is a mild hypopigmented scaly facial dermatosis of atopic children rather than the complete depigmentation described.
- A 52-year-old woman with poorly controlled type 2 diabetes presents with redness, marked swelling, warmth, and tenderness spreading up the lower leg over two days, with poorly defined borders and an associated fever. There is no fluctuant abscess or crepitus. Which is the most appropriate initial management of this cellulitis?
- Topical antibiotic ointment to the affected skin
- Empiric systemic antibiotics covering streptococci and staphylococci, with limb elevation
- Incision and drainage of the inflamed area
- A topical corticosteroid to reduce the redness and swelling
Correct answer: Empiric systemic antibiotics covering streptococci and staphylococci, with limb elevation
Empiric systemic antibiotics directed against streptococci and staphylococci, combined with limb elevation, are the most appropriate initial management because cellulitis is a deeper bacterial infection of the dermis and subcutaneous tissue that requires systemic therapy, particularly in a diabetic patient with fever. Topical antibiotics do not penetrate adequately to treat this depth of infection, incision and drainage is reserved for a drainable abscess that is not present here, and a topical corticosteroid would suppress the inflammatory response without treating the underlying infection.
- A patient with diabetic ketoacidosis has an initial serum potassium of 5.4 mEq/L, yet the team plans to begin potassium replacement soon after starting insulin. Which statement best explains why the total-body potassium is actually depleted despite this normal-to-high measured level?
- Acidosis and insulin deficiency shift potassium out of cells into the blood while urinary losses deplete total stores
- Ketones bind potassium and falsely raise the serum level
- Insulin deficiency causes the kidney to retain potassium avidly
- Hyperglycemia destroys intracellular potassium directly
Correct answer: Acidosis and insulin deficiency shift potassium out of cells into the blood while urinary losses deplete total stores
Acidosis and insulin deficiency shifting potassium out of cells while urinary losses deplete total stores is correct. In diabetic ketoacidosis, transcellular shifts mask a large whole-body deficit caused by osmotic diuresis, so the measured value looks normal or high even though stores are low. Ketones do not bind potassium, insulin deficiency promotes potassium loss rather than retention, and hyperglycemia does not destroy intracellular potassium.
- During treatment of diabetic ketoacidosis, the serum potassium is reported as 3.2 mEq/L before insulin has been started. What is the most appropriate immediate action?
- Begin the insulin infusion immediately at full dose
- Give bicarbonate to correct the acidosis first
- Hold insulin and replace potassium until it rises into a safe range
- Administer a potassium-wasting diuretic
Correct answer: Hold insulin and replace potassium until it rises into a safe range
Holding insulin and replacing potassium until it rises into a safe range is correct. Starting insulin while potassium is below roughly 3.3 mEq/L would drive potassium into cells and precipitate life-threatening hypokalemia and arrhythmia, so potassium is repleted first. Giving full-dose insulin immediately is dangerous, bicarbonate is not the priority, and a diuretic would worsen the deficit.
- A 23-year-old with diabetic ketoacidosis is found to have a bedside beta-hydroxybutyrate that is markedly elevated, but the urine ketone dipstick is only weakly positive early in the course. Which feature of ketone testing best explains this discrepancy?
- Urine dipsticks overestimate ketones in acidosis
- The urine dipstick mainly detects acetoacetate and underdetects the predominant beta-hydroxybutyrate
- Beta-hydroxybutyrate is not a true ketone body
- Blood ketone meters cross-react with glucose
Correct answer: The urine dipstick mainly detects acetoacetate and underdetects the predominant beta-hydroxybutyrate
The urine dipstick mainly detecting acetoacetate and underdetecting beta-hydroxybutyrate is correct. Early in ketoacidosis the dominant ketone is beta-hydroxybutyrate, which the nitroprusside-based urine test does not measure well, so blood beta-hydroxybutyrate better reflects severity. Dipsticks do not overestimate ketones, beta-hydroxybutyrate is a genuine ketone body, and blood meters do not cross-react with glucose.
- A 19-year-old presents in diabetic ketoacidosis and the team debates giving sodium bicarbonate. According to current management principles, when is bicarbonate therapy generally considered in adult diabetic ketoacidosis?
- Routinely for every patient to speed gap closure
- Whenever the glucose exceeds 500 mg/dL
- Only when the arterial pH is very low, such as below 6.9
- As soon as any acidemia is detected on the first gas
Correct answer: Only when the arterial pH is very low, such as below 6.9
Only when the arterial pH is very low, such as below 6.9, is correct. Bicarbonate is reserved for extreme acidemia because insulin and fluids correct the acidosis in most patients and routine bicarbonate can worsen hypokalemia and delay ketone clearance. It is not given routinely, is not based on the glucose level, and is not indicated for mild acidemia.
- A 27-year-old recovering from diabetic ketoacidosis is ready to transition from the intravenous insulin infusion to subcutaneous insulin. To prevent rebound ketoacidosis, how should this transition be managed?
- Stop the infusion and start subcutaneous insulin at the same moment
- Stop the infusion several hours before giving any subcutaneous insulin
- Switch directly to oral agents once the gap closes
- Give the first subcutaneous long-acting dose and overlap it with the infusion for a period before stopping the drip
Correct answer: Give the first subcutaneous long-acting dose and overlap it with the infusion for a period before stopping the drip
Overlapping subcutaneous long-acting insulin with the infusion before stopping the drip is correct. Because intravenous insulin clears within minutes, the subcutaneous dose must be given and allowed to take effect before the infusion is discontinued to avoid a gap in coverage and recurrent ketoacidosis. Stopping abruptly or delaying subcutaneous insulin leaves the patient uncovered, and oral agents cannot replace insulin here.
- A 60-year-old man with a toxic adenoma of the thyroid has overt hyperthyroidism. On a radioactive iodine scan, which pattern is most characteristic of a solitary toxic adenoma?
- A single focal area of intense uptake with suppression of the rest of the gland
- Diffusely increased uptake throughout the gland
- Globally absent uptake
- Multiple scattered hot and cold areas
Correct answer: A single focal area of intense uptake with suppression of the rest of the gland
A single focal area of intense uptake with suppression of the rest of the gland is correct. An autonomously functioning adenoma concentrates iodine while suppressing TSH and therefore the surrounding normal tissue, producing one hot focus. Diffuse uptake suggests Graves disease, absent uptake suggests thyroiditis, and scattered hot and cold areas suggest a toxic multinodular goiter.
- A 35-year-old woman has neck pain radiating to the jaw, fever, a tender thyroid, and transient thyrotoxicosis after a viral illness, with a very low radioactive iodine uptake and an elevated sedimentation rate. Which is the most appropriate treatment for her painful thyroiditis?
- Methimazole to block hormone synthesis
- Radioactive iodine ablation
- Nonsteroidal anti-inflammatory drugs or corticosteroids with a beta-blocker for symptoms
- High-dose levothyroxine
Correct answer: Nonsteroidal anti-inflammatory drugs or corticosteroids with a beta-blocker for symptoms
Nonsteroidal anti-inflammatory drugs or corticosteroids with a beta-blocker is correct. Subacute (de Quervain) thyroiditis is a self-limited inflammatory release of stored hormone, so treatment targets pain and adrenergic symptoms rather than hormone synthesis. Thionamides and radioactive iodine do not help a destructive process with low uptake, and levothyroxine would worsen the thyrotoxic phase.
- A 45-year-old woman with newly diagnosed Graves disease is started on methimazole. Which serious adverse effect should prompt her to stop the drug immediately and seek care if she develops a fever and sore throat?
- Hyperkalemia
- Agranulocytosis
- Pulmonary fibrosis
- Acute pancreatitis
Correct answer: Agranulocytosis
Agranulocytosis is correct. Thionamides such as methimazole can rarely cause a sudden severe drop in neutrophils, so a fever and sore throat must trigger immediate cessation and a white blood cell count. Hyperkalemia, pulmonary fibrosis, and pancreatitis are not the characteristic dangerous reactions to methimazole that this warning addresses.
- A 58-year-old man presents with weight loss, atrial fibrillation, and proximal muscle weakness but lacks the classic adrenergic features of thyrotoxicosis, and is ultimately diagnosed with hyperthyroidism. This presentation in an older adult is best described by which term?
- Euthyroid sick syndrome
- Thyroid storm
- Apathetic hyperthyroidism
- Subclinical hyperthyroidism
Correct answer: Apathetic hyperthyroidism
Apathetic hyperthyroidism is correct. Older adults can present with thyrotoxicosis that is dominated by cardiovascular and constitutional features such as atrial fibrillation, weight loss, and weakness, without the hyperadrenergic signs seen in younger patients. Euthyroid sick syndrome occurs in acute illness, thyroid storm is a hypermetabolic crisis, and subclinical disease has a normal free T4.
- A 32-year-old woman with hyperthyroidism has a low TSH, an elevated free T4, and a high radioactive iodine uptake. Which single test result, when combined with this picture, would most strongly confirm Graves disease as the cause?
- A low erythrocyte sedimentation rate
- An elevated serum thyroglobulin
- A normal serum calcium
- A positive thyrotropin receptor antibody
Correct answer: A positive thyrotropin receptor antibody
A positive thyrotropin receptor antibody is correct. Detecting the stimulating autoantibody directed at the TSH receptor confirms the autoimmune basis of Graves disease, complementing the diffuse high uptake. A low sedimentation rate, an elevated thyroglobulin, and a normal calcium do not specifically establish the diagnosis.
- A 55-year-old woman is incidentally found to have a TSH of 0.1 mIU/L with normal free T4 and free T3 and no symptoms. After confirming the result is persistent, which initial step is most appropriate to evaluate this subclinical hyperthyroidism?
- Begin methimazole empirically
- Determine the underlying cause, often with a radioactive iodine uptake and scan
- Start levothyroxine to normalize the TSH
- Schedule immediate thyroidectomy
Correct answer: Determine the underlying cause, often with a radioactive iodine uptake and scan
Determining the underlying cause with a radioactive iodine uptake and scan is correct. Identifying whether autonomy (such as nodular disease) or another process is responsible guides whether and how to treat persistent subclinical hyperthyroidism. Empiric methimazole and surgery are premature before the cause is known, and levothyroxine would worsen the low TSH.
- A 40-year-old woman with Graves disease wishes to avoid both surgery and radioactive iodine and chooses antithyroid drug therapy. Approximately how long is a typical initial course of methimazole given before assessing for possible remission?
- About 2 weeks
- About 12 to 18 months
- About 5 years minimum
- A single loading dose
Correct answer: About 12 to 18 months
About 12 to 18 months is correct. A course of roughly a year to 18 months gives the best chance of achieving a durable remission of Graves disease before therapy is tapered and the patient reassessed. Two weeks is far too short to evaluate remission, a fixed 5-year minimum is not the standard, and a single dose is not a treatment course.
- A 50-year-old woman with longstanding untreated hypothyroidism is found unresponsive with hypothermia, bradycardia, hyponatremia, and hypercapnia. Which is the most appropriate emergent management of this myxedema coma?
- Oral levothyroxine at a low dose with passive rewarming only
- A beta-blocker and a thionamide
- Intravenous thyroid hormone, stress-dose glucocorticoids, and supportive care
- Aggressive active external rewarming alone
Correct answer: Intravenous thyroid hormone, stress-dose glucocorticoids, and supportive care
Intravenous thyroid hormone, stress-dose glucocorticoids, and supportive care is correct. Myxedema coma is a life-threatening decompensation requiring parenteral thyroid hormone, empiric glucocorticoids to cover possible coexisting adrenal insufficiency, and management of hypothermia and hypoventilation. Low-dose oral therapy is inadequate, thionamides treat the opposite problem, and rewarming alone does not address the hormone deficit.
- A 60-year-old woman taking a stable levothyroxine dose is hospitalized with sepsis, and routine labs show a low TSH, low total T3, and low-normal free T4. She is clinically euthyroid at baseline. What is the most appropriate interpretation?
- New central hypothyroidism requiring a dose increase
- Overtreatment requiring an immediate dose reduction
- Nonthyroidal illness syndrome, best rechecked after recovery
- Onset of Graves disease
Correct answer: Nonthyroidal illness syndrome, best rechecked after recovery
Nonthyroidal illness syndrome, best rechecked after recovery, is correct. Acute severe illness alters thyroid function tests without true thyroid disease, so abnormal values during the acute phase should be reinterpreted once the patient recovers rather than triggering dose changes. The pattern does not indicate central hypothyroidism, overtreatment, or Graves disease.
- A 34-year-old woman who is 8 weeks pregnant has been on levothyroxine for Hashimoto hypothyroidism. What adjustment to her thyroid hormone management is most appropriate in early pregnancy?
- Stop levothyroxine until after delivery
- Switch to liothyronine monotherapy
- Reduce the dose to avoid fetal thyrotoxicosis
- Increase the levothyroxine dose and check TSH frequently with a lower trimester-specific target
Correct answer: Increase the levothyroxine dose and check TSH frequently with a lower trimester-specific target
Increasing the dose with frequent TSH monitoring and a lower trimester-specific target is correct. Pregnancy raises thyroid hormone requirements early, so the dose is typically increased and TSH followed closely to meet pregnancy-specific goals that support fetal development. Stopping or reducing therapy risks maternal and fetal hypothyroidism, and liothyronine monotherapy is not appropriate.
- A 45-year-old woman has symptoms of hypothyroidism, and her clinician orders the single best initial screening test for primary thyroid dysfunction. Which test is the most appropriate first step?
- Serum TSH
- Total T3
- Thyroglobulin
- Reverse T3
Correct answer: Serum TSH
Serum TSH is correct. Because of the sensitive negative-feedback relationship, TSH is the most useful initial screening test for primary thyroid dysfunction, rising early in hypothyroidism before free T4 falls. Total T3, thyroglobulin, and reverse T3 are not appropriate first-line screening tests for suspected hypothyroidism.
- A 52-year-old man taking chronic high-dose prednisone for an autoimmune disease is admitted for surgery and becomes hypotensive perioperatively. Which mechanism explains his risk for adrenal insufficiency in this setting?
- Autoimmune destruction of the adrenal cortex
- Suppression of the hypothalamic-pituitary-adrenal axis by long-term exogenous steroids
- A pituitary hemorrhage from surgery
- Mineralocorticoid receptor blockade
Correct answer: Suppression of the hypothalamic-pituitary-adrenal axis by long-term exogenous steroids
Suppression of the hypothalamic-pituitary-adrenal axis by long-term exogenous steroids is correct. Prolonged glucocorticoid therapy suppresses endogenous ACTH and cortisol production, so the axis cannot mount a stress response, producing tertiary adrenal insufficiency that requires perioperative stress dosing. This is not autoimmune adrenal destruction, pituitary hemorrhage, or mineralocorticoid blockade.
- A patient with suspected adrenal insufficiency has a cosyntropin stimulation test that shows an appropriate cortisol rise, yet the baseline ACTH is low and the morning cortisol is low. Which diagnosis does this combination most support?
- Primary adrenal insufficiency (Addison disease)
- Secondary (central) adrenal insufficiency
- Cushing syndrome
- Pheochromocytoma
Correct answer: Secondary (central) adrenal insufficiency
Secondary (central) adrenal insufficiency is correct. A low ACTH with a low cortisol but a preserved response to cosyntropin indicates the adrenal glands are intact but understimulated because of pituitary or hypothalamic ACTH deficiency. Primary adrenal insufficiency raises ACTH and fails the stimulation test, while Cushing syndrome and pheochromocytoma present quite differently.
- A patient with confirmed primary adrenal insufficiency is established on hydrocortisone and fludrocortisone. Which monitoring parameter best reflects adequacy of the mineralocorticoid component of replacement?
- Serum TSH
- Hemoglobin A1c
- Blood pressure, serum potassium, and plasma renin activity
- Serum calcium
Correct answer: Blood pressure, serum potassium, and plasma renin activity
Blood pressure, serum potassium, and plasma renin activity is correct. Mineralocorticoid replacement is titrated to keep blood pressure, potassium, and renin in target ranges because fludrocortisone controls sodium and volume balance. TSH, A1c, and calcium do not assess mineralocorticoid sufficiency.
- A 30-year-old woman with autoimmune primary adrenal insufficiency should be evaluated for which commonly associated coexisting endocrine disorder?
- Acromegaly
- Primary hyperaldosteronism
- Carcinoid syndrome
- Autoimmune thyroid disease
Correct answer: Autoimmune thyroid disease
Autoimmune thyroid disease is correct. Autoimmune Addison disease frequently clusters with other autoimmune endocrinopathies, particularly thyroid disease and type 1 diabetes, as part of an autoimmune polyglandular syndrome. Acromegaly, primary hyperaldosteronism, and carcinoid syndrome are not part of this autoimmune association.
- A 55-year-old man with type 2 diabetes and stage 3 chronic kidney disease has an A1c above goal. Which oral agent is contraindicated or requires discontinuation once the estimated GFR falls below about 30 mL/min because of accumulation risk?
- Metformin
- A DPP-4 inhibitor with dose adjustment
- An SGLT2 inhibitor for glycemic benefit
- Pioglitazone
Correct answer: Metformin
Metformin is correct. Metformin is cleared renally and is contraindicated when the estimated GFR falls below roughly 30 mL/min because accumulation raises the risk of lactic acidosis. DPP-4 inhibitors can be dose-adjusted, SGLT2 inhibitors have efficacy thresholds but are used for kidney benefit, and pioglitazone is not contraindicated by low GFR in the same way.
- A 48-year-old man with type 2 diabetes and albuminuric chronic kidney disease is already on metformin and an ACE inhibitor. Which add-on glucose-lowering class is preferred specifically to slow progression of his diabetic kidney disease?
- A sulfonylurea
- A DPP-4 inhibitor
- An SGLT2 inhibitor
- An alpha-glucosidase inhibitor
Correct answer: An SGLT2 inhibitor
An SGLT2 inhibitor is correct. In type 2 diabetes with albuminuric chronic kidney disease, SGLT2 inhibitors slow decline in kidney function and reduce albuminuria beyond glucose lowering, making them the preferred add-on. Sulfonylureas, DPP-4 inhibitors, and alpha-glucosidase inhibitors do not provide this kidney protection.
- A 60-year-old man with type 2 diabetes asks why his clinician orders a urine albumin-to-creatinine ratio and an estimated GFR every year. Which is the primary purpose of this annual testing?
- To screen for diabetic kidney disease so treatment can begin early
- To adjust his insulin carbohydrate ratio
- To diagnose diabetic retinopathy
- To monitor his thyroid function
Correct answer: To screen for diabetic kidney disease so treatment can begin early
Screening for diabetic kidney disease so treatment can begin early is correct. Annual urine albumin and estimated GFR detect early diabetic nephropathy, allowing renoprotective therapy before significant function is lost. These tests do not set insulin ratios, diagnose retinopathy, or monitor the thyroid.
- A 50-year-old woman with type 2 diabetes has a fasting glucose at goal but a persistently elevated A1c, and her postprandial readings are high. Which therapeutic adjustment most directly targets her postprandial hyperglycemia?
- Increasing the basal (long-acting) insulin
- Adding a mealtime rapid-acting insulin or a short-acting prandial agent
- Adding a bedtime sedative
- Reducing her total daily insulin
Correct answer: Adding a mealtime rapid-acting insulin or a short-acting prandial agent
Adding a mealtime rapid-acting insulin or short-acting prandial agent is correct. When fasting glucose is controlled but postprandial values and A1c remain high, prandial coverage targets the mealtime excursions driving the elevated A1c. Increasing basal insulin would risk fasting hypoglycemia, a sedative is irrelevant, and reducing insulin would worsen control.
- A 42-year-old woman started on a GLP-1 receptor agonist for type 2 diabetes reports nausea and early satiety in the first weeks. Which mechanism of the drug class most directly accounts for these gastrointestinal effects?
- Inhibition of intestinal glucose absorption
- Slowing of gastric emptying
- Increased renal glucose excretion
- Stimulation of hepatic gluconeogenesis
Correct answer: Slowing of gastric emptying
Slowing of gastric emptying is correct. GLP-1 receptor agonists delay gastric emptying and increase satiety, which commonly causes early nausea that often improves with gradual dose escalation. Inhibiting glucose absorption, increasing renal glucose excretion, and stimulating gluconeogenesis are not the mechanisms behind these symptoms.
- A 58-year-old man with type 2 diabetes well controlled on metformin and an SGLT2 inhibitor is scheduled for a major elective surgery requiring prolonged fasting. Which periprocedural medication instruction is most appropriate to reduce the risk of euglycemic ketoacidosis?
- Continue all agents through the morning of surgery
- Hold the SGLT2 inhibitor several days before the procedure
- Double the SGLT2 inhibitor dose preoperatively
- Add a sulfonylurea the night before
Correct answer: Hold the SGLT2 inhibitor several days before the procedure
Holding the SGLT2 inhibitor several days before the procedure is correct. Because SGLT2 inhibitors can precipitate euglycemic ketoacidosis during fasting, illness, or surgical stress, they are stopped a few days before major procedures. Continuing or doubling the drug raises the ketoacidosis risk, and adding a sulfonylurea does not address this concern.
- A 65-year-old man with type 2 diabetes and a recent acute coronary syndrome is reviewed for additional glucose-lowering therapy. Which two drug classes are specifically favored for patients with established cardiovascular disease because of demonstrated reductions in cardiovascular events?
- Sulfonylureas and thiazolidinediones
- DPP-4 inhibitors and alpha-glucosidase inhibitors
- GLP-1 receptor agonists and SGLT2 inhibitors with proven benefit
- Basal insulin and meglitinides
Correct answer: GLP-1 receptor agonists and SGLT2 inhibitors with proven benefit
GLP-1 receptor agonists and SGLT2 inhibitors with proven benefit is correct. These two classes have trial evidence of reducing major adverse cardiovascular events and are preferred in patients with established atherosclerotic cardiovascular disease regardless of A1c. Sulfonylureas, thiazolidinediones, DPP-4 inhibitors, alpha-glucosidase inhibitors, insulin, and meglitinides lack comparable cardiovascular outcome benefit.
- A 55-year-old man with type 2 diabetes has not had a dilated eye examination since diagnosis 5 years ago. According to current preventive care, how often should a patient with type 2 diabetes generally undergo a comprehensive dilated retinal examination if no retinopathy is present?
- Every month
- At least every 1 to 2 years
- Only if vision changes occur
- Once in a lifetime
Correct answer: At least every 1 to 2 years
At least every 1 to 2 years is correct. Regular dilated retinal examinations detect diabetic retinopathy early, and screening at intervals of one to two years is recommended when no retinopathy is present, with more frequent exams if disease is found. Monthly exams are excessive, waiting for symptoms misses early disease, and a single lifetime exam is inadequate.
- A 70-year-old woman with primary hyperparathyroidism, a calcium of 11.1 mg/dL, and no symptoms is being evaluated for whether to pursue surgery. Which finding would most strongly support proceeding with parathyroidectomy rather than observation?
- Age over 65 alone
- A reduced bone mineral density with osteoporosis on a DXA scan
- A family history of hypertension
- A normal 24-hour urine calcium
Correct answer: A reduced bone mineral density with osteoporosis on a DXA scan
A reduced bone mineral density with osteoporosis on DXA is correct. Documented osteoporosis is an established indication for parathyroidectomy in asymptomatic primary hyperparathyroidism, along with significant hypercalcemia, reduced kidney function, kidney stones, and younger age. Age over 65 alone, a family history of hypertension, and a normal urine calcium do not on their own justify surgery.
- A patient with severe symptomatic hypercalcemia from malignancy has received intravenous fluids, and the team adds a medication to durably lower calcium over the next several days by inhibiting bone resorption. Which agent works through this mechanism?
- A loop diuretic
- Oral calcium carbonate
- An intravenous bisphosphonate
- A thiazide diuretic
Correct answer: An intravenous bisphosphonate
An intravenous bisphosphonate is correct. Bisphosphonates inhibit osteoclast-mediated bone resorption, providing a sustained reduction in calcium that takes a few days to take full effect after initial fluid resuscitation. A loop diuretic alone is not the durable answer, oral calcium would raise calcium, and thiazides reduce calcium excretion and worsen hypercalcemia.
- A patient with hypercalcemia of malignancy has calcium that remains elevated despite saline and a bisphosphonate. Which agent provides rapid calcium lowering by directly inhibiting osteoclast activity within hours, useful as a bridge?
- Calcitonin
- Hydrochlorothiazide
- Vitamin D
- Spironolactone
Correct answer: Calcitonin
Calcitonin is correct. Calcitonin lowers calcium quickly by inhibiting osteoclasts and increasing renal calcium excretion, serving as a short-term bridge while a bisphosphonate takes effect, though tachyphylaxis limits prolonged use. A thiazide and vitamin D raise calcium, and spironolactone does not lower it.
- A 62-year-old man is found to have hypercalcemia with a suppressed PTH, a low PTH-related protein, and an elevated 1,25-dihydroxyvitamin D level. Which category of disease most likely underlies this finding?
- Primary hyperparathyroidism
- Familial hypocalciuric hypercalcemia
- A thiazide effect
- A granulomatous disease such as sarcoidosis
Correct answer: A granulomatous disease such as sarcoidosis
A granulomatous disease such as sarcoidosis is correct. Granulomas produce extra-renal 1-alpha-hydroxylase that raises active vitamin D, causing PTH-independent hypercalcemia with a suppressed PTH and a low PTH-related protein. Primary hyperparathyroidism shows a non-suppressed PTH, familial hypocalciuric hypercalcemia has a normal PTH with low urine calcium, and a thiazide does not raise active vitamin D.
- A clinician evaluating hypercalcemia wants to determine quickly whether the cause is PTH-dependent or PTH-independent. Which single test best makes this initial distinction?
- 24-hour urine calcium
- An intact parathyroid hormone level measured at the same time as calcium
- A vitamin D level
- A serum phosphate level
Correct answer: An intact parathyroid hormone level measured at the same time as calcium
An intact parathyroid hormone level measured with calcium is correct. A simultaneous PTH separates PTH-dependent causes, in which PTH is high or inappropriately normal, from PTH-independent causes, in which PTH is suppressed, directing the rest of the workup. Urine calcium, vitamin D, and phosphate are useful later but do not make this primary branch-point distinction.
- A 70-year-old woman with hyperthyroidism from a toxic multinodular goiter is not a surgical candidate and has cardiac comorbidities. Which definitive therapy is generally preferred for toxic nodular disease in such a patient?
- Lifelong methimazole as the definitive cure
- Radioactive iodine
- Levothyroxine
- Observation without treatment
Correct answer: Radioactive iodine
Radioactive iodine is correct. For toxic nodular goiter in a patient who is not a surgical candidate, radioactive iodine ablates the autonomous tissue and is a preferred definitive treatment, since nodular autonomy does not remit on drugs. Lifelong methimazole is control rather than cure for nodular disease, levothyroxine would worsen thyrotoxicosis, and observation leaves the hyperthyroidism untreated.
- A 24-year-old with type 1 diabetes asks how to prevent diabetic ketoacidosis during a viral gastroenteritis with poor oral intake. Which sick-day instruction is most appropriate?
- Stop all insulin until eating returns to normal
- Take only mealtime insulin and skip basal insulin
- Continue basal insulin, monitor glucose and ketones frequently, and stay hydrated
- Double all insulin doses regardless of glucose
Correct answer: Continue basal insulin, monitor glucose and ketones frequently, and stay hydrated
Continuing basal insulin while monitoring glucose and ketones and staying hydrated is correct. During illness, people with type 1 diabetes must keep taking background insulin to suppress ketogenesis, check glucose and ketones often, and maintain fluids to prevent ketoacidosis. Stopping insulin or omitting basal insulin precipitates ketoacidosis, and blindly doubling doses risks hypoglycemia.
- A 48-year-old woman with type 2 diabetes asks how her A1c relates to her average blood glucose. Approximately what estimated average glucose corresponds to an A1c of 7 percent?
- About 90 mg/dL
- About 154 mg/dL
- About 250 mg/dL
- About 350 mg/dL
Correct answer: About 154 mg/dL
About 154 mg/dL is correct. An A1c of 7 percent corresponds to an estimated average glucose of roughly 154 mg/dL, a relationship used to help patients interpret their A1c in terms of day-to-day readings. An average near 90 would reflect a much lower A1c, while 250 and 350 mg/dL correspond to substantially higher A1c values.
- A 33-year-old woman with Graves disease that recurred after a course of methimazole is counseled on definitive options. She has no significant orbitopathy and is not pregnant. Compared with radioactive iodine, which is the main advantage of total thyroidectomy as definitive treatment in a patient who prefers immediate, certain resolution?
- It avoids the need for any lifelong thyroid hormone replacement
- It rapidly and reliably eliminates the thyrotoxicosis in a single procedure
- It prevents the need for any preoperative control of hyperthyroidism
- It carries no risk to the parathyroid glands or recurrent laryngeal nerve
Correct answer: It rapidly and reliably eliminates the thyrotoxicosis in a single procedure
Rapidly and reliably eliminating the thyrotoxicosis in a single procedure is correct. Surgery removes the overactive gland immediately and definitively, which appeals to patients wanting prompt, certain resolution. It still requires lifelong levothyroxine, demands preoperative euthyroidism to avoid storm, and carries risks to the parathyroid glands and recurrent laryngeal nerve.
- A 26-year-old woman with type 1 diabetes presents with abdominal pain, vomiting, glucose of 480 mg/dL, and an anion-gap acidosis with ketones. After confirming the diagnosis, which is the cornerstone initial intervention before insulin is started in most protocols?
- Intravenous isotonic fluid resuscitation
- A bolus of subcutaneous long-acting insulin
- Empiric broad-spectrum antibiotics
- Sodium bicarbonate infusion
Correct answer: Intravenous isotonic fluid resuscitation
Intravenous isotonic fluid resuscitation is correct. Patients in diabetic ketoacidosis are profoundly volume depleted, so isotonic fluids are started first to restore perfusion and begin lowering glucose, with potassium assessed before and during the insulin infusion. A long-acting subcutaneous bolus is not the acute approach, antibiotics are given only if infection is found, and bicarbonate is reserved for extreme acidemia.
- A 28-year-old woman has 6 months of bloody diarrhea, urgency, and lower abdominal cramping. Colonoscopy shows continuous inflammation extending from the rectum proximally to the splenic flexure with no skip areas, and biopsies show crypt abscesses limited to the mucosa. Which feature best supports ulcerative colitis rather than Crohn disease in this patient?
- Transmural inflammation with noncaseating granulomas
- Continuous mucosal inflammation beginning at the rectum without intervening normal segments
- Perianal fistulas and rectal sparing
- Patchy small-bowel involvement on imaging
Correct answer: Continuous mucosal inflammation beginning at the rectum without intervening normal segments
Continuous mucosal inflammation starting at the rectum and extending proximally without skip lesions is the answer because ulcerative colitis is a mucosal disease that begins in the rectum and spreads contiguously. Transmural inflammation with granulomas, perianal fistulas with rectal sparing, and patchy small-bowel disease are hallmarks of Crohn disease, which characteristically spares the rectum and produces skip lesions.
- A 34-year-old man with Crohn disease involving the terminal ileum has had recurrent flares despite maximized mesalamine and is now requiring frequent corticosteroid courses to control symptoms. He has no abscess on imaging. Which therapy is most appropriate to achieve steroid-free maintenance of remission?
- Long-term daily prednisone
- Empiric metronidazole alone indefinitely
- An anti-tumor necrosis factor biologic such as infliximab
- Loperamide scheduled around the clock
Correct answer: An anti-tumor necrosis factor biologic such as infliximab
An anti-tumor necrosis factor agent such as infliximab is the answer because steroid-dependent Crohn disease warrants escalation to a biologic to induce and maintain steroid-free remission. Chronic prednisone causes cumulative toxicity and is not a maintenance strategy, metronidazole treats perianal disease rather than maintaining luminal remission, and loperamide is only symptomatic and does not modify the inflammatory process.
- A 45-year-old woman with long-standing ulcerative colitis involving the entire colon for 12 years presents for routine care. She is currently in remission. Beyond symptom control, which surveillance intervention is most important to recommend because of her disease history?
- Annual upper endoscopy to screen for varices
- Routine small-bowel capsule endoscopy yearly
- Serial abdominal ultrasound for gallstones
- Surveillance colonoscopy with biopsies to detect dysplasia
Correct answer: Surveillance colonoscopy with biopsies to detect dysplasia
Surveillance colonoscopy with biopsies for dysplasia is the answer because long-standing extensive colitis substantially raises colorectal cancer risk, and periodic colonoscopy beginning roughly 8 years after diagnosis is recommended to detect dysplasia early. Variceal screening, capsule endoscopy, and gallstone ultrasound are unrelated to the cancer risk that defines this patient's surveillance need.
- A 50-year-old man with a history of heavy alcohol use presents with severe 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 initial management step is most appropriate?
- Aggressive intravenous fluid resuscitation and analgesia
- Immediate emergent ERCP regardless of biliary findings
- Empiric broad-spectrum antibiotics for all patients
- Urgent surgical pancreatic resection
Correct answer: Aggressive intravenous fluid resuscitation and analgesia
Aggressive intravenous fluid resuscitation with analgesia is the answer because early goal-directed fluids and pain control are the cornerstone of acute pancreatitis management and reduce complications. Emergent ERCP is reserved for cholangitis or biliary obstruction, prophylactic antibiotics are not indicated in uncomplicated pancreatitis, and early surgery is not part of initial management.
- A 62-year-old woman presents with acute epigastric pain, an elevated lipase, and laboratory testing notable for elevated alkaline phosphatase and direct bilirubin. Right upper quadrant ultrasound shows cholelithiasis and a dilated common bile duct. What is the most likely etiology of her acute pancreatitis?
- Hypertriglyceridemia
- Gallstone obstruction of the pancreatic duct
- Autoimmune pancreatitis
- Anatomic pancreas divisum
Correct answer: Gallstone obstruction of the pancreatic duct
Gallstone obstruction is the answer because cholelithiasis with a dilated bile duct and a cholestatic pattern of liver tests points to a stone obstructing the common channel and triggering pancreatitis. Hypertriglyceridemia would show markedly elevated triglycerides, autoimmune pancreatitis presents with a different imaging and serologic picture, and pancreas divisum is a less common congenital cause not suggested by these findings.
- A 55-year-old man with alcohol-related cirrhosis presents with hematemesis and melena. He is tachycardic and hypotensive. After resuscitation with intravenous fluids and blood products, which combination of interventions is most appropriate for suspected variceal bleeding?
- Oral proton pump inhibitor alone and discharge
- Immediate transjugular intrahepatic portosystemic shunt before endoscopy in all patients
- A vasoactive agent such as octreotide plus urgent endoscopy and prophylactic antibiotics
- Nasogastric lavage with cold saline as definitive therapy
Correct answer: A vasoactive agent such as octreotide plus urgent endoscopy and prophylactic antibiotics
A vasoactive agent such as octreotide combined with urgent endoscopy and prophylactic antibiotics is the answer because octreotide lowers portal pressure, endoscopic band ligation controls the source, and antibiotics reduce infection and mortality in cirrhotic GI bleeding. An oral proton pump inhibitor alone is inadequate, TIPS is a rescue measure after failed endoscopy, and cold saline lavage is not therapeutic.
- A 60-year-old man presents with coffee-ground emesis and melena. He takes daily naproxen for arthritis. He is hemodynamically stable. Endoscopy reveals a gastric ulcer with a clean base and no active bleeding. Which long-term step most directly reduces his risk of recurrent ulcer bleeding?
- Switching from naproxen to a higher dose of the same drug
- Discontinuing the nonsteroidal anti-inflammatory drug and starting a proton pump inhibitor
- Beginning chronic aspirin therapy
- Starting scheduled sucralfate as monotherapy without stopping naproxen
Correct answer: Discontinuing the nonsteroidal anti-inflammatory drug and starting a proton pump inhibitor
Stopping the nonsteroidal anti-inflammatory drug and starting a proton pump inhibitor is the answer because NSAID-induced ulcers heal and recur far less when the offending drug is removed and acid suppression is given. Increasing the NSAID dose or adding aspirin raises bleeding risk, and sucralfate without removing the NSAID does not address the underlying cause.
- A 70-year-old woman presents with painless passage of bright red blood per rectum and clots. She is hemodynamically stable after fluids. Vital signs normalize and bleeding slows. Which is the most appropriate next diagnostic step to localize the source?
- Upper endoscopy as the first study
- Empiric segmental colectomy
- Colonoscopy after bowel preparation
- Barium enema
Correct answer: Colonoscopy after bowel preparation
Colonoscopy after a bowel preparation is the answer because in a stable patient with lower GI bleeding, colonoscopy both identifies common sources such as diverticulosis or angiodysplasia and allows therapy. Upper endoscopy is first only when an upper source is suspected, surgery is reserved for uncontrolled bleeding, and barium enema obscures the mucosa and prevents intervention.
- A 65-year-old man with cirrhosis is found to have a hemoglobin of 7 g/dL and ongoing GI bleeding. There is no active cardiac ischemia. According to current evidence, what is the most appropriate red blood cell transfusion strategy?
- A liberal threshold transfusing to keep hemoglobin above 10 g/dL
- Withholding transfusion until hemoglobin falls below 5 g/dL
- Transfusing platelets instead of red cells regardless of platelet count
- A restrictive threshold transfusing around a hemoglobin of 7 g/dL
Correct answer: A restrictive threshold transfusing around a hemoglobin of 7 g/dL
A restrictive transfusion threshold near 7 g/dL is the answer because in acute upper GI bleeding a restrictive strategy improves survival compared with liberal transfusion, partly by avoiding rises in portal pressure that worsen variceal bleeding. A liberal goal of 10 g/dL, waiting until below 5 g/dL, and substituting platelets are all inappropriate for this scenario.
- A 58-year-old man with cirrhosis presents with increasing abdominal distension. Paracentesis of ascitic fluid reveals an absolute neutrophil count of 350 cells per microliter. He is afebrile but has mild abdominal tenderness. What is the most appropriate diagnosis and management?
- Uncomplicated ascites managed with diuretics alone
- Spontaneous bacterial peritonitis requiring empiric intravenous antibiotics
- Secondary peritonitis requiring urgent laparotomy
- Chylous ascites requiring a low-fat diet only
Correct answer: Spontaneous bacterial peritonitis requiring empiric intravenous antibiotics
Spontaneous bacterial peritonitis treated with empiric intravenous antibiotics is the answer because an ascitic neutrophil count of 250 cells per microliter or higher establishes the diagnosis and mandates prompt antibiotics such as a third-generation cephalosporin. Diuretics alone do not treat infection, surgical peritonitis has a different fluid profile, and chylous ascites does not present with neutrophilia.
- A 64-year-old woman with cirrhosis becomes confused and somnolent over two days. She has asterixis and an elevated ammonia level, and a urinary tract infection is identified as a precipitant. After treating the precipitant, which medication is first-line to reduce her hepatic encephalopathy?
- Intravenous mannitol
- High-protein nutritional supplementation
- Lactulose titrated to two to three soft stools per day
- Chronic benzodiazepine sedation
Correct answer: Lactulose titrated to two to three soft stools per day
Lactulose titrated to two to three soft stools daily is the answer because it traps and eliminates ammonia in the gut and is the cornerstone of hepatic encephalopathy treatment. Mannitol treats cerebral edema not encephalopathy, severe protein restriction is no longer recommended, and benzodiazepines worsen encephalopathy.
- A 59-year-old man with cirrhosis and large esophageal varices that have never bled is evaluated for primary prophylaxis. He has no contraindications to standard therapy. Which intervention is most appropriate to reduce his risk of a first variceal hemorrhage?
- Daily aspirin
- A loop diuretic alone
- Empiric antibiotics indefinitely
- A nonselective beta-blocker such as nadolol or carvedilol
Correct answer: A nonselective beta-blocker such as nadolol or carvedilol
A nonselective beta-blocker such as nadolol or carvedilol is the answer because lowering portal pressure with a nonselective beta-blocker is established primary prophylaxis for large varices, with endoscopic band ligation as an alternative. Aspirin increases bleeding risk, a loop diuretic treats ascites rather than varices, and chronic antibiotics are not used for primary variceal prophylaxis.
- A 41-year-old woman reports heartburn and acid regurgitation several times weekly for 3 months, worse when lying down after meals. She has no dysphagia, weight loss, anemia, or GI bleeding. What is the most appropriate initial management?
- An empiric trial of a once-daily proton pump inhibitor with lifestyle modification
- Immediate upper endoscopy before any therapy
- Empiric antibiotics for Helicobacter pylori without testing
- Surgical fundoplication as first-line treatment
Correct answer: An empiric trial of a once-daily proton pump inhibitor with lifestyle modification
An empiric proton pump inhibitor trial with lifestyle changes is the answer because typical reflux symptoms without alarm features are managed initially with acid suppression and weight, dietary, and positional modification. Endoscopy is reserved for alarm features or treatment failure, empiric H. pylori therapy without testing is inappropriate, and surgery is not first-line.
- A 55-year-old man with a 10-year history of chronic reflux undergoes upper endoscopy that reveals salmon-colored mucosa extending above the gastroesophageal junction, and biopsies confirm intestinal metaplasia without dysplasia. What does this finding represent and how should it be managed?
- Eosinophilic esophagitis requiring topical steroids
- An infectious esophagitis requiring antifungal therapy
- Barrett esophagus requiring proton pump inhibitor therapy and periodic endoscopic surveillance
- A normal variant requiring no follow-up
Correct answer: Barrett esophagus requiring proton pump inhibitor therapy and periodic endoscopic surveillance
Barrett esophagus managed with a proton pump inhibitor and periodic surveillance is the answer because intestinal metaplasia replacing the normal squamous mucosa is the defining feature of Barrett esophagus, which carries a risk of progression to esophageal adenocarcinoma and warrants endoscopic surveillance. Eosinophilic esophagitis, infectious esophagitis, and a normal variant do not match this histology.
- A 47-year-old man has recurrent epigastric pain that improves with eating. Testing for Helicobacter pylori with a stool antigen test is positive, and endoscopy shows a duodenal ulcer. Which treatment approach is most appropriate?
- A proton pump inhibitor alone without antibiotics
- Combination antibiotic therapy plus a proton pump inhibitor to eradicate Helicobacter pylori
- Indefinite NSAID therapy for pain control
- Surgical vagotomy as initial therapy
Correct answer: Combination antibiotic therapy plus a proton pump inhibitor to eradicate Helicobacter pylori
Combination antibiotics with a proton pump inhibitor to eradicate Helicobacter pylori is the answer because eradication heals the ulcer and prevents recurrence in H. pylori-associated peptic ulcer disease. A proton pump inhibitor alone leaves the infection untreated, NSAIDs worsen ulcers, and surgery is reserved for refractory or complicated disease.
- A 38-year-old woman is treated for a Helicobacter pylori-associated peptic ulcer with a standard eradication regimen. She has no ongoing symptoms after completing therapy. Which step best confirms successful eradication?
- Serum H. pylori IgG antibody testing immediately after treatment
- No confirmatory testing because symptom resolution proves cure
- A urea breath test or stool antigen test performed at least four weeks after completing therapy
- Repeating the same antibiotic regimen empirically
Correct answer: A urea breath test or stool antigen test performed at least four weeks after completing therapy
A urea breath test or stool antigen test at least four weeks after therapy is the answer because these tests detect active infection and confirm eradication once antibiotics and acid suppression have been stopped long enough to avoid false negatives. Serology stays positive after cure, symptom resolution does not prove eradication, and repeating treatment empirically is not confirmation.
- A 32-year-old woman has chronic diarrhea, bloating, iron deficiency anemia, and an itchy vesicular rash on the elbows. Serologic testing shows elevated tissue transglutaminase IgA antibodies while she is consuming gluten. Which test best confirms the suspected diagnosis?
- Colonoscopy with random colonic biopsies
- Hydrogen breath test for lactose intolerance
- Stool culture for enteric pathogens
- Duodenal biopsy showing villous atrophy
Correct answer: Duodenal biopsy showing villous atrophy
Duodenal biopsy showing villous atrophy is the answer because celiac disease is confirmed by small-bowel histology demonstrating villous blunting, intraepithelial lymphocytosis, and crypt hyperplasia in a patient with positive serology eating gluten. Colonic biopsy, lactose breath testing, and stool culture do not evaluate the small-bowel mucosa where celiac damage occurs.
- A 26-year-old woman has recurrent crampy abdominal pain relieved by defecation, with alternating constipation and loose stools for over a year. She has no weight loss, rectal bleeding, anemia, or nocturnal symptoms, and her examination and basic labs are normal. Which diagnosis and approach is most appropriate?
- Colon cancer requiring immediate resection
- Irritable bowel syndrome diagnosed clinically with dietary and symptom-directed management
- Acute mesenteric ischemia requiring angiography
- Clostridioides difficile colitis requiring oral vancomycin
Correct answer: Irritable bowel syndrome diagnosed clinically with dietary and symptom-directed management
Irritable bowel syndrome diagnosed clinically is the answer because chronic abdominal pain related to defecation with altered bowel habits and no alarm features meets symptom-based criteria, allowing diagnosis without extensive testing and management with diet and symptom-targeted therapy. The absence of alarm features and normal findings make cancer, mesenteric ischemia, and C. difficile colitis unlikely.
- A 67-year-old man presents with left lower quadrant pain, low-grade fever, and a mild leukocytosis. CT shows sigmoid colonic wall thickening with pericolic fat stranding and no abscess or perforation. He tolerates oral intake. What is the most appropriate management of this uncomplicated diverticulitis?
- Emergent sigmoid colectomy
- Immediate colonoscopy during the acute episode
- Supportive care with close follow-up, with selective rather than routine antibiotics in mild cases
- Long-term daily corticosteroids
Correct answer: Supportive care with close follow-up, with selective rather than routine antibiotics in mild cases
Supportive care with close follow-up and selective antibiotic use is the answer because mild uncomplicated diverticulitis is increasingly managed without routine antibiotics in appropriately selected, immunocompetent patients with adequate follow-up. Emergent surgery is for complicated disease, colonoscopy is deferred until after resolution to evaluate for malignancy, and steroids have no role.
- A 44-year-old man is found to have an alanine aminotransferase and aspartate aminotransferase elevated to roughly two times normal on routine testing. He is obese with type 2 diabetes, drinks minimal alcohol, and has negative viral hepatitis serologies. Ultrasound shows a fatty liver. What is the most likely diagnosis?
- Acute hepatitis A infection
- Wilson disease
- Primary biliary cholangitis
- Nonalcoholic fatty liver disease
Correct answer: Nonalcoholic fatty liver disease
Nonalcoholic fatty liver disease is the answer because hepatic steatosis with mild transaminase elevation in a patient with obesity and diabetes and negative viral serologies and minimal alcohol use is the classic presentation. Acute hepatitis A causes a much higher transaminase rise with symptoms, Wilson disease presents in younger patients with neuropsychiatric findings, and primary biliary cholangitis produces a cholestatic pattern.
- A 36-year-old woman is found to have a positive hepatitis C antibody on screening. Which test most appropriately confirms active, ongoing infection?
- Hepatitis C antibody repeated in three months
- Hepatitis C virus RNA by polymerase chain reaction
- Hepatitis B surface antigen
- Serum alpha-fetoprotein
Correct answer: Hepatitis C virus RNA by polymerase chain reaction
Hepatitis C virus RNA testing is the answer because a positive antibody indicates exposure but cannot distinguish active from cleared infection, so a quantitative RNA assay confirms ongoing viremia and guides treatment. Repeating the antibody does not establish active infection, hepatitis B surface antigen tests a different virus, and alpha-fetoprotein screens for hepatocellular carcinoma rather than confirming infection.
- A 29-year-old man who is hepatitis B surface antigen positive is being evaluated. Which laboratory pattern indicates that he is in a phase requiring closer monitoring or treatment consideration because of active viral replication?
- Isolated hepatitis B surface antibody positivity
- Hepatitis A IgG positivity alone
- Hepatitis B e antigen positive with high HBV DNA and elevated ALT
- Negative hepatitis B surface antigen with positive core IgG only
Correct answer: Hepatitis B e antigen positive with high HBV DNA and elevated ALT
Hepatitis B e antigen positivity with high HBV DNA and elevated ALT is the answer because this combination signals active viral replication and hepatic inflammation, marking a phase that warrants closer monitoring and possible antiviral therapy. Isolated surface antibody indicates immunity, hepatitis A IgG reflects a different virus, and resolved infection shows surface antigen negativity with core IgG.
- A 52-year-old woman has fatigue and intense pruritus, and labs show a markedly elevated alkaline phosphatase with normal aminotransferases. Antimitochondrial antibody is strongly positive. What is the most likely diagnosis?
- Alcoholic hepatitis
- Hemochromatosis
- Acute cholecystitis
- Primary biliary cholangitis
Correct answer: Primary biliary cholangitis
Primary biliary cholangitis is the answer because a cholestatic pattern with elevated alkaline phosphatase, pruritus, and a positive antimitochondrial antibody in a middle-aged woman is the characteristic presentation, and ursodeoxycholic acid is the treatment. Alcoholic hepatitis raises aminotransferases in a hepatocellular pattern, hemochromatosis causes iron overload, and acute cholecystitis presents with acute right upper quadrant pain.
- A 58-year-old man with newly diagnosed cirrhosis has serum bilirubin, albumin, and INR measured along with assessment for ascites and encephalopathy. Which scoring system uses bilirubin, INR, and creatinine to estimate prognosis and prioritize liver transplant allocation?
- The CHA2DS2-VASc score
- The Model for End-Stage Liver Disease score
- The Wells score
- The CURB-65 score
Correct answer: The Model for End-Stage Liver Disease score
The Model for End-Stage Liver Disease score is the answer because it combines bilirubin, INR, and creatinine to quantify short-term mortality risk in advanced liver disease and prioritize transplant listing. The CHA2DS2-VASc, Wells, and CURB-65 scores assess stroke risk in atrial fibrillation, venous thromboembolism probability, and pneumonia severity, respectively.
- A 60-year-old woman presents with right upper quadrant pain, fever, and jaundice. She is hypotensive. Imaging shows a dilated common bile duct with an obstructing stone. After resuscitation and antibiotics, which intervention is most appropriate?
- Outpatient observation with oral antibiotics
- Elective cholecystectomy in six weeks without decompression
- Long-term ursodeoxycholic acid alone
- Urgent endoscopic retrograde cholangiopancreatography for biliary decompression
Correct answer: Urgent endoscopic retrograde cholangiopancreatography for biliary decompression
Urgent endoscopic retrograde cholangiopancreatography for biliary decompression is the answer because the triad of right upper quadrant pain, fever, and jaundice with hypotension indicates ascending cholangitis with obstruction, which requires prompt antibiotics and urgent drainage of the infected biliary tree. Outpatient observation, deferred surgery without decompression, and ursodeoxycholic acid do not relieve the life-threatening obstruction.
- A 45-year-old obese woman presents with several hours of constant severe right upper quadrant pain after a fatty meal, fever, and a positive Murphy sign. Ultrasound shows gallbladder wall thickening, pericholecystic fluid, and gallstones. What is the most likely diagnosis?
- Uncomplicated biliary colic
- Acute cholecystitis
- Acute viral hepatitis
- Gastroesophageal reflux disease
Correct answer: Acute cholecystitis
Acute cholecystitis is the answer because constant prolonged right upper quadrant pain with fever, a positive Murphy sign, and ultrasound showing wall thickening and pericholecystic fluid indicates inflammation of the gallbladder rather than transient biliary colic. Biliary colic resolves within hours without inflammatory signs, viral hepatitis causes diffuse hepatocellular injury, and reflux produces retrosternal burning.
- A 55-year-old man with cirrhosis and tense ascites refractory to maximal diuretics undergoes a large-volume paracentesis of 6 liters. Which adjunctive measure reduces the risk of post-paracentesis circulatory dysfunction?
- Aggressive normal saline boluses
- Immediate restart of high-dose diuretics
- Intravenous albumin infusion
- Fresh frozen plasma for every paracentesis
Correct answer: Intravenous albumin infusion
Intravenous albumin infusion is the answer because giving albumin after a large-volume paracentesis (generally over 5 liters) supports effective circulating volume and prevents the renal and hemodynamic compromise of post-paracentesis circulatory dysfunction. Saline boluses are less effective, restarting high-dose diuretics worsens volume depletion, and fresh frozen plasma is not routinely indicated.
- A 48-year-old man with decompensated cirrhosis develops a progressive rise in creatinine. Workup shows no shock, no nephrotoxic drugs, a benign urinalysis without significant proteinuria, and no improvement after stopping diuretics and giving albumin. What is the most likely diagnosis?
- Acute tubular necrosis from contrast
- Postrenal obstruction
- Acute glomerulonephritis
- Hepatorenal syndrome
Correct answer: Hepatorenal syndrome
Hepatorenal syndrome is the answer because progressive kidney failure in advanced cirrhosis with a bland urine sediment, minimal proteinuria, and no response to volume expansion after diuretic withdrawal is the defining picture of this functional renal failure. Acute tubular necrosis shows granular casts, obstruction shows hydronephrosis, and glomerulonephritis produces an active sediment with proteinuria.
- A 70-year-old man with atrial fibrillation presents with sudden severe, diffuse abdominal pain that is markedly out of proportion to a relatively benign abdominal examination. Lactate is elevated. Which diagnosis must be urgently considered?
- Functional dyspepsia
- Acute mesenteric ischemia
- Chronic constipation
- Lactose intolerance
Correct answer: Acute mesenteric ischemia
Acute mesenteric ischemia is the answer because pain out of proportion to examination in a patient with atrial fibrillation and an elevated lactate strongly suggests an embolic occlusion of mesenteric arterial flow, a surgical emergency requiring urgent CT angiography and revascularization. Functional dyspepsia, constipation, and lactose intolerance do not cause this acute ischemic syndrome.
- A 30-year-old man has intermittent solid-food dysphagia and episodes of food impaction. Upper endoscopy shows concentric rings and linear furrows, and esophageal biopsies reveal more than 15 eosinophils per high-power field despite acid suppression. What is the most likely diagnosis?
- Achalasia
- Esophageal candidiasis
- Eosinophilic esophagitis
- Diffuse esophageal spasm
Correct answer: Eosinophilic esophagitis
Eosinophilic esophagitis is the answer because a young patient with solid-food dysphagia and food impaction whose endoscopy shows rings and furrows and whose biopsies show dense eosinophilia despite proton pump inhibitor therapy fits this allergic-mediated condition. Achalasia shows aperistalsis and a tight lower sphincter, candidiasis shows white plaques, and esophageal spasm shows a motility pattern without eosinophilia.
- A 58-year-old woman has progressive dysphagia to both solids and liquids and regurgitation of undigested food. Barium esophagram shows a dilated esophagus with a smooth tapering bird-beak narrowing at the gastroesophageal junction. Which test best confirms the diagnosis?
- Twenty-four hour ambulatory pH monitoring
- Helicobacter pylori stool antigen testing
- Gastric emptying scintigraphy
- Esophageal manometry showing absent peristalsis and incomplete lower esophageal sphincter relaxation
Correct answer: Esophageal manometry showing absent peristalsis and incomplete lower esophageal sphincter relaxation
Esophageal manometry showing absent peristalsis with incomplete lower esophageal sphincter relaxation is the answer because achalasia is confirmed manometrically, consistent with the bird-beak appearance and dysphagia to solids and liquids. Ambulatory pH testing evaluates reflux, H. pylori testing assesses ulcer disease, and gastric scintigraphy assesses gastroparesis rather than esophageal motility.
- A 45-year-old man with poorly controlled type 1 diabetes has early satiety, postprandial nausea, vomiting of undigested food, and bloating. Upper endoscopy is normal and shows no obstruction. Which test best confirms the suspected diagnosis?
- Colonoscopy with biopsies
- A gastric emptying scintigraphy study showing delayed emptying
- Right upper quadrant ultrasound
- Esophageal pH monitoring
Correct answer: A gastric emptying scintigraphy study showing delayed emptying
Gastric emptying scintigraphy showing delayed emptying is the answer because diabetic gastroparesis is confirmed by demonstrating delayed solid emptying after mechanical obstruction has been excluded by normal endoscopy. Colonoscopy evaluates the colon, ultrasound assesses the biliary tree, and esophageal pH monitoring evaluates reflux, none of which assess gastric motility.
- A 73-year-old man on a proton pump inhibitor and recent broad-spectrum antibiotics develops profuse watery diarrhea and abdominal cramping. Stool testing is positive for toxigenic Clostridioides difficile. For this initial nonsevere episode, which oral therapy is preferred first-line?
- Intravenous metronidazole as the sole agent
- Loperamide alone
- Oral fidaxomicin or oral vancomycin
- A broad-spectrum fluoroquinolone
Correct answer: Oral fidaxomicin or oral vancomycin
Oral fidaxomicin or oral vancomycin is the answer because current guidance favors these agents over metronidazole even for an initial nonsevere Clostridioides difficile episode given superior cure and lower recurrence. Intravenous metronidazole alone is inferior for luminal disease, antimotility agents alone risk toxic megacolon, and additional antibiotics worsen the dysbiosis.
- A 25-year-old woman has chronic diarrhea, bloating, and flatulence that worsen after consuming dairy products and improve with dairy avoidance. She has no weight loss, anemia, or blood in the stool. Which test most directly confirms the suspected condition?
- Tissue transglutaminase antibody testing
- Colonoscopy with random biopsies
- A hydrogen breath test after a lactose load
- Fecal occult blood testing
Correct answer: A hydrogen breath test after a lactose load
A hydrogen breath test after a lactose load is the answer because lactose intolerance is confirmed by a rise in breath hydrogen from unabsorbed lactose fermented by colonic bacteria, matching the symptom-trigger pattern. Tissue transglutaminase testing screens for celiac disease, colonoscopy evaluates structural disease, and fecal occult blood testing screens for bleeding rather than malabsorption.
- A 55-year-old man with cirrhosis and known esophageal varices that previously bled has completed an endoscopic band ligation program. Which combination is most appropriate for secondary prophylaxis against recurrent variceal bleeding?
- Aspirin plus clopidogrel
- A proton pump inhibitor alone
- Scheduled large-volume paracentesis
- A nonselective beta-blocker plus repeated endoscopic band ligation until varices are obliterated
Correct answer: A nonselective beta-blocker plus repeated endoscopic band ligation until varices are obliterated
A nonselective beta-blocker combined with serial band ligation is the answer because the most effective secondary prophylaxis after a variceal bleed pairs pharmacologic portal pressure reduction with endoscopic eradication of varices. Dual antiplatelet therapy increases bleeding, a proton pump inhibitor alone does not address portal hypertension, and paracentesis treats ascites not varices.
- A 40-year-old woman presents with painless jaundice, pale stools, dark urine, and pruritus, and labs show a cholestatic pattern with markedly elevated alkaline phosphatase and direct bilirubin. Which finding distinguishes cholestatic (obstructive) jaundice from a hepatocellular process?
- Predominant marked aminotransferase elevation with normal alkaline phosphatase
- Elevated indirect bilirubin with normal liver enzymes
- Isolated elevation of lactate dehydrogenase
- Predominant elevation of alkaline phosphatase and direct bilirubin with relatively lower aminotransferases
Correct answer: Predominant elevation of alkaline phosphatase and direct bilirubin with relatively lower aminotransferases
A predominant rise in alkaline phosphatase and direct bilirubin with comparatively modest aminotransferases is the answer because this cholestatic pattern indicates impaired bile flow, prompting imaging for biliary obstruction. A marked aminotransferase rise indicates hepatocellular injury, isolated indirect hyperbilirubinemia suggests hemolysis or Gilbert syndrome, and isolated lactate dehydrogenase elevation is nonspecific.
- A 38-year-old man with alcohol use disorder is admitted with jaundice, tender hepatomegaly, fever, and an aspartate aminotransferase that is roughly twice the alanine aminotransferase, with both under 300 units per liter. Bilirubin is markedly elevated. What is the most likely diagnosis?
- Alcoholic hepatitis
- Acute viral hepatitis C
- Choledocholithiasis
- Hemochromatosis
Correct answer: Alcoholic hepatitis
Alcoholic hepatitis is the answer because jaundice, tender hepatomegaly, fever, and an AST-to-ALT ratio greater than 2 with transaminases typically below 300 in a patient with heavy alcohol use is the characteristic biochemical and clinical picture. Acute hepatitis C usually causes higher and ALT-predominant transaminases, choledocholithiasis gives a cholestatic pattern, and hemochromatosis is a chronic iron-overload disorder.
- A 68-year-old woman with severe constipation and abdominal distension is found to have a markedly dilated colon on imaging without a mechanical obstruction, in the setting of recent surgery and opioids. Which condition does this represent?
- Acute colonic pseudo-obstruction
- Sigmoid volvulus
- Toxic megacolon from infection
- Small-bowel obstruction from adhesions
Correct answer: Acute colonic pseudo-obstruction
Acute colonic pseudo-obstruction is the answer because massive colonic dilation without a mechanical cause in a hospitalized postoperative patient on opioids is the classic setting for this motility disorder, managed by correcting precipitants, decompression, and neostigmine when needed. Volvulus shows a twisted segment, toxic megacolon involves severe colitis, and small-bowel obstruction shows mechanical small-bowel findings.
- A 42-year-old woman with heavy menstrual bleeding reports fatigue and exertional dyspnea. Her hemoglobin is low, the mean corpuscular volume is reduced, the serum ferritin is markedly low, and the total iron-binding capacity is elevated. Which diagnosis best fits this pattern?
- Anemia of chronic disease
- Sideroblastic anemia
- Iron deficiency anemia
- Folate deficiency anemia
Correct answer: Iron deficiency anemia
Iron deficiency anemia best fits because a low mean corpuscular volume, a low ferritin, and an elevated total iron-binding capacity together indicate depleted body iron stores, classically from chronic blood loss such as heavy menses. Low ferritin is the most specific marker of iron depletion. Anemia of chronic disease typically shows a low or normal iron-binding capacity with a normal or high ferritin, sideroblastic anemia features iron overload rather than depletion, and folate deficiency produces a macrocytic rather than microcytic anemia.
- A 68-year-old man is newly diagnosed with iron deficiency anemia. He has no overt bleeding source and reports no menstrual losses. Which evaluation is most appropriate to identify the underlying cause?
- Bone marrow biopsy as the initial test
- Empiric lifelong oral iron without further workup
- Endoscopic evaluation of the gastrointestinal tract to exclude a bleeding lesion or malignancy
- Measurement of erythropoietin levels
Correct answer: Endoscopic evaluation of the gastrointestinal tract to exclude a bleeding lesion or malignancy
Endoscopic evaluation of the gastrointestinal tract is most appropriate because in an older adult without an obvious source, iron deficiency anemia is presumed to result from occult gastrointestinal blood loss until proven otherwise, and colorectal cancer is an important consideration. Identifying the source can be lifesaving. A bone marrow biopsy is rarely needed for straightforward iron deficiency, empiric iron without investigation could mask a malignancy, and erythropoietin measurement does not localize the bleeding source.
- A patient with iron deficiency anemia is started on oral ferrous sulfate. Which laboratory change is expected to appear earliest as a sign that the marrow is responding to therapy?
- Normalization of ferritin within 48 hours
- An immediate increase in mean corpuscular volume
- A rise in the reticulocyte count within about one to two weeks
- A prompt drop in total iron-binding capacity within one day
Correct answer: A rise in the reticulocyte count within about one to two weeks
A rise in the reticulocyte count within about one to two weeks is the earliest sign of a marrow response because effective iron repletion allows the bone marrow to accelerate red cell production before the hemoglobin fully normalizes. Reticulocytosis precedes the correction of hemoglobin. Ferritin reflects stores and recovers gradually rather than within two days, the mean corpuscular volume corrects slowly over weeks, and the iron-binding capacity does not fall within a single day.
- A 55-year-old woman is found to have a microcytic anemia. To distinguish iron deficiency from beta-thalassemia trait, which laboratory finding most strongly favors iron deficiency anemia?
- A normal or elevated red cell count with mild anemia
- An elevated hemoglobin A2 on electrophoresis
- A low serum ferritin
- A normal red cell distribution width
Correct answer: A low serum ferritin
A low serum ferritin most strongly favors iron deficiency anemia because depleted iron stores are the defining feature, whereas thalassemia trait has normal or increased iron stores. Ferritin is the key discriminator between the two microcytic anemias. A normal or high red cell count with only mild anemia and an elevated hemoglobin A2 both point toward thalassemia trait, and iron deficiency typically widens rather than normalizes the red cell distribution width.
- A 28-year-old previously healthy woman presents with petechiae, gum bleeding, and an isolated platelet count of 12,000 per microliter. Her hemoglobin, white count, peripheral smear, and coagulation studies are otherwise normal, and she has no splenomegaly. Which diagnosis is most likely?
- Disseminated intravascular coagulation
- Thrombotic thrombocytopenic purpura
- Aplastic anemia
- Immune thrombocytopenia
Correct answer: Immune thrombocytopenia
Immune thrombocytopenia is most likely because isolated severe thrombocytopenia with mucocutaneous bleeding, a normal smear apart from low platelets, and no other cytopenias or organomegaly reflects autoantibody-mediated platelet destruction. It is a diagnosis of exclusion in an otherwise well patient. Disseminated intravascular coagulation would show abnormal coagulation studies, thrombotic thrombocytopenic purpura features microangiopathic hemolysis with schistocytes, and aplastic anemia involves pancytopenia rather than isolated thrombocytopenia.
- A 40-year-old woman presents with fever, confusion, anemia, thrombocytopenia, and renal dysfunction. The peripheral smear shows numerous schistocytes, and coagulation studies are normal. Which diagnosis must be recognized urgently and treated with plasma exchange?
- Immune thrombocytopenia
- Vitamin B12 deficiency
- Hereditary spherocytosis
- Thrombotic thrombocytopenic purpura
Correct answer: Thrombotic thrombocytopenic purpura
Thrombotic thrombocytopenic purpura must be recognized urgently because microangiopathic hemolytic anemia with schistocytes, thrombocytopenia, neurologic changes, and renal involvement with normal coagulation studies reflects a deficiency of ADAMTS13 and platelet-rich microthrombi, and plasma exchange is lifesaving. Prompt treatment dramatically reduces mortality. Immune thrombocytopenia lacks hemolysis and organ dysfunction, vitamin B12 deficiency causes macrocytic anemia without schistocytes, and hereditary spherocytosis produces spherocytes rather than the pentad of thrombotic microangiopathy.
- A hospitalized patient receiving unfractionated heparin develops a fall in the platelet count to less than half of baseline about six days after starting the drug, along with a new lower-extremity arterial clot. Which condition is most likely responsible?
- Disseminated intravascular coagulation
- Dilutional thrombocytopenia
- Heparin-induced thrombocytopenia
- Immune thrombocytopenia
Correct answer: Heparin-induced thrombocytopenia
Heparin-induced thrombocytopenia is most likely because a platelet drop of roughly 50 percent occurring five to ten days after heparin exposure, paradoxically accompanied by new thrombosis, reflects antibodies against platelet factor 4-heparin complexes that activate platelets. Heparin must be stopped and a nonheparin anticoagulant started. Disseminated intravascular coagulation shows consumptive coagulopathy with abnormal clotting tests, dilutional thrombocytopenia follows massive transfusion, and immune thrombocytopenia is not triggered by this heparin-timed pattern with thrombosis.
- A clinician evaluating a patient with a low platelet count reviews the peripheral blood smear and finds platelet clumping. The patient has no bleeding. Which explanation should be considered before initiating any treatment?
- Active disseminated intravascular coagulation
- Thrombotic thrombocytopenic purpura
- Pseudothrombocytopenia from EDTA-induced platelet clumping
- Bone marrow failure
Correct answer: Pseudothrombocytopenia from EDTA-induced platelet clumping
Pseudothrombocytopenia from EDTA-induced platelet clumping should be considered because antibodies that agglutinate platelets in the presence of the EDTA anticoagulant produce a falsely low automated platelet count without any true bleeding risk. Repeating the count in a citrate tube confirms the artifact. Disseminated intravascular coagulation and thrombotic thrombocytopenic purpura cause genuine thrombocytopenia with systemic illness, and bone marrow failure produces real cytopenias rather than an in-vitro clumping artifact.
- A 24-year-old woman with newly diagnosed immune thrombocytopenia has a platelet count of 8,000 per microliter with wet purpura and mucosal bleeding. Which initial treatment is most appropriate to rapidly raise the platelet count?
- Platelet transfusion as definitive therapy
- Corticosteroids, often with intravenous immunoglobulin for severe bleeding
- Splenectomy as the first-line intervention
- Observation alone regardless of bleeding
Correct answer: Corticosteroids, often with intravenous immunoglobulin for severe bleeding
Corticosteroids, often combined with intravenous immunoglobulin when bleeding is severe, are the most appropriate initial treatment because they suppress autoantibody-mediated platelet destruction and immunoglobulin rapidly blocks splenic clearance to boost the count. This addresses the immune mechanism. Routine platelet transfusion is largely ineffective as transfused platelets are destroyed, splenectomy is reserved for refractory disease rather than initial therapy, and observation is inappropriate with active significant bleeding.
- A 64-year-old man presents with bone pain, fatigue, and recurrent infections. Laboratory studies show anemia, hypercalcemia, an elevated creatinine, and a monoclonal protein spike on serum electrophoresis. A skeletal survey reveals multiple lytic lesions. Which diagnosis is most consistent with these findings?
- Chronic lymphocytic leukemia
- Hodgkin lymphoma
- Multiple myeloma
- Polycythemia vera
Correct answer: Multiple myeloma
Multiple myeloma is most consistent because the CRAB features of hypercalcemia, renal insufficiency, anemia, and lytic bone lesions together with a monoclonal protein reflect a clonal plasma cell proliferation. These end-organ findings define symptomatic disease. Chronic lymphocytic leukemia produces a lymphocytosis without lytic lesions or an M-protein, Hodgkin lymphoma presents with lymphadenopathy and B symptoms, and polycythemia vera causes erythrocytosis rather than anemia and bone destruction.
- Which set of clinical findings is captured by the CRAB criteria used to define end-organ damage in multiple myeloma?
- Cough, rash, arthralgia, and bradycardia
- Hypercalcemia, renal insufficiency, anemia, and lytic bone lesions
- Chest pain, reflux, ascites, and bruising
- Cyanosis, rigors, alopecia, and bleeding
Correct answer: Hypercalcemia, renal insufficiency, anemia, and lytic bone lesions
Hypercalcemia, renal insufficiency, anemia, and bone lesions are the CRAB criteria, each representing a form of end-organ damage that distinguishes symptomatic multiple myeloma requiring treatment from asymptomatic precursor states. These features drive the decision to treat. The other options list unrelated symptoms that do not correspond to the established myeloma-defining end-organ events, and they are not used in staging or diagnostic criteria for plasma cell myeloma.
- A 70-year-old man with suspected multiple myeloma has a monoclonal protein detected in serum. Which test is most appropriate to confirm the diagnosis by demonstrating the clonal plasma cell burden?
- Peripheral blood smear alone
- Bone marrow biopsy showing increased clonal plasma cells
- Erythrocyte sedimentation rate
- Serum ferritin measurement
Correct answer: Bone marrow biopsy showing increased clonal plasma cells
A bone marrow biopsy showing an increased percentage of clonal plasma cells is most appropriate because the diagnosis of multiple myeloma requires direct demonstration of the malignant plasma cell population in the marrow alongside the M-protein and end-organ damage. The marrow quantifies the clonal burden. A peripheral smear may show rouleaux but does not establish the diagnosis, the erythrocyte sedimentation rate is nonspecific, and serum ferritin assesses iron stores rather than plasma cell clonality.
- A patient with multiple myeloma develops worsening renal function. Which mechanism most directly explains the kidney injury characteristic of this plasma cell disorder?
- Bilateral renal artery thrombosis
- Acute glomerulonephritis from anti-GBM antibodies
- Obstructing bladder stones
- Deposition of monoclonal free light chains causing cast nephropathy
Correct answer: Deposition of monoclonal free light chains causing cast nephropathy
Deposition of monoclonal free light chains causing cast nephropathy most directly explains the renal injury because the excess immunoglobulin light chains produced by malignant plasma cells precipitate in the renal tubules, obstructing and damaging them. Hypercalcemia and dehydration can compound this injury. Renal artery thrombosis is not a typical myeloma mechanism, anti-glomerular basement membrane antibodies cause a distinct pulmonary-renal syndrome, and obstructing bladder stones reflect a different anatomic problem unrelated to plasma cell disease.
- A 58-year-old asymptomatic man is found incidentally to have a small monoclonal protein with less than 10 percent clonal plasma cells in the marrow and no anemia, hypercalcemia, renal failure, or bone lesions. Which term best describes this condition?
- Symptomatic multiple myeloma
- Monoclonal gammopathy of undetermined significance
- Waldenstrom macroglobulinemia
- Amyloid light-chain amyloidosis
Correct answer: Monoclonal gammopathy of undetermined significance
Monoclonal gammopathy of undetermined significance best describes this condition because a low-level M-protein with fewer than 10 percent marrow plasma cells and no CRAB end-organ damage represents a premalignant state that requires monitoring rather than treatment. It carries a small annual risk of progression to myeloma. Symptomatic myeloma requires end-organ damage, Waldenstrom macroglobulinemia involves an IgM paraprotein with lymphoplasmacytic infiltration, and amyloidosis features organ deposition of misfolded light chains.
- A 56-year-old man presents with unilateral leg swelling, calf tenderness, and warmth that developed over two days after a long-haul flight. A compression ultrasound shows a noncompressible femoral vein. Which diagnosis is most consistent with these findings?
- Cellulitis
- Deep vein thrombosis
- Lymphedema
- Ruptured Baker cyst
Correct answer: Deep vein thrombosis
Deep vein thrombosis is most consistent because acute unilateral leg swelling, tenderness, and warmth after prolonged immobility, with a noncompressible vein on ultrasound, indicate an obstructing venous clot. The ultrasound finding confirms the diagnosis. Cellulitis presents with spreading erythema and skin findings rather than a noncompressible vein, lymphedema develops gradually and is usually painless, and a ruptured Baker cyst causes posterior knee and calf symptoms without an intraluminal venous thrombus.
- A 60-year-old woman is diagnosed with an acute proximal lower-extremity deep vein thrombosis without renal impairment or active cancer. Which treatment is the preferred initial anticoagulant for most such patients?
- Aspirin alone
- A direct oral anticoagulant such as apixaban or rivaroxaban
- Intravenous unfractionated heparin for lifelong therapy
- An inferior vena cava filter instead of anticoagulation
Correct answer: A direct oral anticoagulant such as apixaban or rivaroxaban
A direct oral anticoagulant such as apixaban or rivaroxaban is the preferred initial therapy for most patients with deep vein thrombosis because these agents provide effective anticoagulation with predictable dosing and no required monitoring, and they are favored over warfarin in patients without contraindications. They simplify outpatient management. Aspirin is inadequate for acute treatment, lifelong intravenous heparin is impractical, and an inferior vena cava filter is reserved for patients in whom anticoagulation is contraindicated.
- A 34-year-old man with no provoking factors develops a spontaneous deep vein thrombosis and reports that his father and sister both had clots at young ages. Which underlying condition is the most common inherited thrombophilia to consider?
- Hemophilia A
- Von Willebrand disease
- Glucose-6-phosphate dehydrogenase deficiency
- Factor V Leiden mutation
Correct answer: Factor V Leiden mutation
Factor V Leiden mutation is the most common inherited thrombophilia and a leading consideration in a young patient with unprovoked venous thrombosis and a strong family history of clotting. The mutation makes factor V resistant to inactivation by activated protein C, promoting clot formation. Hemophilia A and von Willebrand disease are bleeding disorders rather than prothrombotic states, and glucose-6-phosphate dehydrogenase deficiency causes hemolysis rather than thrombosis.
- A clinician uses the Wells criteria to assess a patient with possible deep vein thrombosis and calculates a low pretest probability. Which next step is most appropriate to safely exclude the diagnosis?
- Immediately start lifelong anticoagulation
- Obtain a D-dimer, and if negative the diagnosis can be reasonably excluded
- Proceed directly to venography in all patients
- Order a ventilation-perfusion scan
Correct answer: Obtain a D-dimer, and if negative the diagnosis can be reasonably excluded
Obtaining a D-dimer is most appropriate because in a patient with a low pretest probability of deep vein thrombosis, a negative high-sensitivity D-dimer has a strong negative predictive value and can reasonably exclude the diagnosis without imaging. This avoids unnecessary testing. Starting lifelong anticoagulation before confirming a clot is inappropriate, invasive venography is not a first-line approach, and a ventilation-perfusion scan evaluates the lungs for pulmonary embolism rather than leg veins.
- A 19-year-old man with known sickle cell disease presents with acute severe pain in his back, chest, and long bones after a respiratory infection and cold exposure. He is afebrile with stable vital signs and a normal chest examination. Which complication is most consistent with this presentation?
- Acute chest syndrome
- Aplastic crisis
- Splenic sequestration
- Acute vaso-occlusive pain crisis
Correct answer: Acute vaso-occlusive pain crisis
An acute vaso-occlusive pain crisis is most consistent because sudden severe pain in the back, chest wall, and long bones triggered by infection or cold, without pulmonary findings, reflects microvascular occlusion by sickled erythrocytes causing tissue ischemia. Management centers on hydration and analgesia. Acute chest syndrome requires a new pulmonary infiltrate with respiratory symptoms, aplastic crisis presents with a sudden drop in hemoglobin and low reticulocytes, and splenic sequestration causes a rapidly enlarging spleen with falling hemoglobin.
- A 22-year-old woman with sickle cell disease develops fever, chest pain, hypoxia, and a new pulmonary infiltrate on chest imaging. Which complication does this presentation most likely represent?
- Uncomplicated vaso-occlusive crisis
- Iron deficiency anemia
- Hereditary spherocytosis
- Acute chest syndrome
Correct answer: Acute chest syndrome
Acute chest syndrome most likely represents this presentation because fever, chest pain, hypoxemia, and a new pulmonary infiltrate in a patient with sickle cell disease define this life-threatening complication caused by pulmonary vaso-occlusion, infection, or fat embolism. It requires prompt oxygen, antibiotics, and often transfusion. An uncomplicated pain crisis lacks a new infiltrate and hypoxia, iron deficiency anemia does not cause acute pulmonary infiltrates, and hereditary spherocytosis is an unrelated hemolytic disorder.
- A patient with sickle cell disease is started on a medication to reduce the frequency of pain crises and acute chest syndrome by increasing fetal hemoglobin. Which agent is this?
- Hydroxyurea
- Warfarin
- Methotrexate
- Allopurinol
Correct answer: Hydroxyurea
Hydroxyurea is correct because it increases fetal hemoglobin, which interferes with the polymerization of sickle hemoglobin and thereby reduces the frequency of vaso-occlusive pain crises and acute chest syndrome. It is a cornerstone of disease-modifying therapy. Warfarin is an anticoagulant without a role in raising fetal hemoglobin, methotrexate is an immunosuppressant used for other conditions, and allopurinol lowers uric acid and does not modify sickle hemoglobin polymerization.
- A young adult with sickle cell disease develops a sudden, profound drop in hemoglobin with an inappropriately low reticulocyte count after a viral illness. Which infection is the classic precipitant of this aplastic crisis?
- Parvovirus B19
- Hepatitis C virus
- Cytomegalovirus
- Respiratory syncytial virus
Correct answer: Parvovirus B19
Parvovirus B19 is the classic precipitant because it transiently infects and shuts down erythroid precursors in the bone marrow, causing a sudden fall in hemoglobin with reticulocytopenia in patients whose chronic hemolysis already shortens red cell survival. The marrow cannot compensate during the suppression. Hepatitis C, cytomegalovirus, and respiratory syncytial virus do not characteristically cause the pure red cell aplasia that produces an aplastic crisis in sickle cell disease.
- A 30-year-old man with sickle cell disease asks about preventive care. Which intervention is most important to reduce his risk of life-threatening infection given his functional asplenia?
- Routine vaccination against encapsulated organisms such as pneumococcus and meningococcus
- Daily oral iron supplementation
- Avoidance of all childhood vaccines
- Lifelong therapeutic anticoagulation
Correct answer: Routine vaccination against encapsulated organisms such as pneumococcus and meningococcus
Routine vaccination against encapsulated organisms such as pneumococcus and meningococcus is most important because repeated splenic infarction leaves patients functionally asplenic and highly susceptible to overwhelming infection from encapsulated bacteria. Immunization, often with penicillin prophylaxis in childhood, is central to prevention. Daily iron is unnecessary and risks overload in a hemolytic state, avoiding vaccines would increase infection risk, and lifelong anticoagulation is not a standard preventive measure for sickle cell disease.
- A 72-year-old man presents with fatigue and is found to have a hemoglobin that is low with a mean corpuscular volume above 110 femtoliters. The peripheral smear shows hypersegmented neutrophils and oval macrocytes. Which deficiency should be suspected as the cause of this macrocytic anemia?
- Vitamin B12 or folate deficiency
- Iron deficiency
- Copper deficiency
- Vitamin K deficiency
Correct answer: Vitamin B12 or folate deficiency
Vitamin B12 or folate deficiency should be suspected because a markedly elevated mean corpuscular volume with hypersegmented neutrophils and oval macrocytes is characteristic of megaloblastic anemia caused by impaired DNA synthesis. Measuring both vitamin levels guides treatment. Iron deficiency causes a microcytic rather than macrocytic anemia, copper deficiency can cause cytopenias but not classic megaloblastic features, and vitamin K deficiency produces a coagulopathy rather than anemia.
- A 65-year-old man undergoes routine bloodwork and is found to have a markedly elevated white blood cell count with a predominance of mature small lymphocytes, and the smear shows numerous smudge cells. He is asymptomatic. Which diagnosis is most consistent with these findings?
- Chronic lymphocytic leukemia
- Acute myeloid leukemia
- Multiple myeloma
- Hairy cell leukemia
Correct answer: Chronic lymphocytic leukemia
Chronic lymphocytic leukemia is most consistent because a sustained lymphocytosis of mature-appearing small lymphocytes with smudge cells on the smear in an older, often asymptomatic adult reflects an indolent clonal B-cell proliferation. Flow cytometry confirms the clonal phenotype. Acute myeloid leukemia presents with blasts and acute marrow failure, multiple myeloma involves plasma cells and an M-protein rather than lymphocytosis, and hairy cell leukemia features characteristic cytoplasmic projections with pancytopenia and splenomegaly.
- A 50-year-old woman is found to have polycythemia with an elevated hemoglobin and hematocrit, splenomegaly, and aquagenic pruritus. Her erythropoietin level is low, and testing reveals a JAK2 V617F mutation. Which diagnosis is most consistent with these findings?
- Polycythemia vera
- Secondary polycythemia from chronic hypoxia
- Relative polycythemia from dehydration
- Iron deficiency anemia
Correct answer: Polycythemia vera
Polycythemia vera is most consistent because an absolute erythrocytosis with a low erythropoietin level, splenomegaly, itching after warm water, and a JAK2 mutation reflects a clonal myeloproliferative neoplasm with autonomous red cell production. The suppressed erythropoietin distinguishes it from secondary causes. Secondary polycythemia from hypoxia raises erythropoietin, relative polycythemia from dehydration reflects plasma contraction with a normal red cell mass, and iron deficiency causes anemia rather than erythrocytosis.
- A 26-year-old man with hemophilia A presents after a minor injury with a markedly swollen, painful knee from spontaneous bleeding. His prothrombin time is normal but the activated partial thromboplastin time is prolonged. Which clotting factor deficiency explains this presentation?
- Factor VIII deficiency
- Factor VII deficiency
- Von Willebrand factor excess
- Protein C deficiency
Correct answer: Factor VIII deficiency
Factor VIII deficiency explains this presentation because hemophilia A is an X-linked disorder characterized by deficient factor VIII, producing spontaneous deep tissue and joint bleeding (hemarthrosis) with an isolated prolongation of the activated partial thromboplastin time and a normal prothrombin time. Replacement of factor VIII treats and prevents bleeding. Factor VII deficiency prolongs the prothrombin time instead, an excess of von Willebrand factor does not cause bleeding, and protein C deficiency is a thrombotic rather than bleeding disorder.
- A 19-year-old college student presents with fatigue, jaundice, and dark urine after starting an antimalarial medication. Laboratory studies show a low hemoglobin, elevated indirect bilirubin, low haptoglobin, and bite cells with Heinz bodies on the peripheral smear. Which enzyme deficiency best explains this episode of hemolysis?
- Pyruvate kinase deficiency
- Hexokinase deficiency
- Adenosine deaminase deficiency
- Glucose-6-phosphate dehydrogenase deficiency
Correct answer: Glucose-6-phosphate dehydrogenase deficiency
Glucose-6-phosphate dehydrogenase deficiency best explains this episode because the X-linked enzyme defect leaves red cells unable to withstand oxidative stress, so an oxidant drug triggers acute hemolysis marked by bite cells, Heinz bodies, a low haptoglobin, and an indirect hyperbilirubinemia. The exposure-triggered, episodic hemolysis is characteristic. Pyruvate kinase deficiency causes a chronic nonspherocytic hemolytic anemia without Heinz bodies, hexokinase deficiency is rare and not oxidant-triggered in this way, and adenosine deaminase deficiency causes severe combined immunodeficiency rather than hemolysis.
- A 60-year-old man with chronic obstructive pulmonary disease is admitted with severe community-acquired pneumonia requiring intensive care. The treating team wants empiric coverage that includes atypical pathogens. Which empiric regimen best meets the standard recommendation for an inpatient with severe community-acquired pneumonia and no specific risk factors for resistant organisms?
- A beta-lactam such as ceftriaxone plus a macrolide such as azithromycin
- Oral amoxicillin alone
- Oral doxycycline alone
- Vancomycin plus aztreonam
Correct answer: A beta-lactam such as ceftriaxone plus a macrolide such as azithromycin
The correct choice is a beta-lactam such as ceftriaxone combined with a macrolide such as azithromycin. For severe community-acquired pneumonia in the inpatient and intensive care setting, guidelines recommend a beta-lactam plus either a macrolide or a respiratory fluoroquinolone to cover both typical organisms like Streptococcus pneumoniae and atypicals like Legionella and Mycoplasma. Oral amoxicillin or doxycycline monotherapy is reserved for low-risk outpatients and is inadequate for severe disease. Vancomycin plus aztreonam targets resistant organisms and does not reliably cover atypicals, so it is not the standard empiric base.
- A 45-year-old previously healthy man is treated as an outpatient for community-acquired pneumonia. He has no comorbidities, no recent antibiotics, and no risk factors for drug-resistant Streptococcus pneumoniae. Which oral monotherapy is an appropriate first-line option for this low-risk outpatient?
- Vancomycin
- Amoxicillin at a high dose
- Intravenous piperacillin-tazobactam
- Oral metronidazole
Correct answer: Amoxicillin at a high dose
High-dose amoxicillin is the appropriate first-line option here. For a healthy outpatient with community-acquired pneumonia and no comorbidities or resistance risk factors, current guidelines endorse high-dose amoxicillin, doxycycline, or a macrolide where pneumococcal resistance is low. Vancomycin and piperacillin-tazobactam are intravenous agents reserved for hospitalized patients with resistant-organism risk and are inappropriate for a low-risk outpatient. Metronidazole covers anaerobes and has no role as monotherapy for typical pneumonia.
- A 70-year-old man with poorly controlled diabetes develops cellulitis of the leg with no abscess, no purulent drainage, and no systemic toxicity. He has no risk factors that suggest methicillin-resistant Staphylococcus aureus. Which pathogen group is the most likely cause of nonpurulent cellulitis and should drive empiric therapy?
- Beta-hemolytic streptococci
- Anaerobic gram-negative rods
- Pseudomonas aeruginosa
- Candida species
Correct answer: Beta-hemolytic streptococci
Beta-hemolytic streptococci are the most likely cause and should drive empiric therapy. Nonpurulent cellulitis is predominantly streptococcal, so empiric coverage targets streptococci with agents such as cephalexin; methicillin-resistant Staphylococcus aureus coverage is reserved for purulent infections or specific risk factors. Pseudomonas and anaerobic gram-negative rods are not typical causes of uncomplicated nonpurulent cellulitis. Candida does not cause routine cellulitis in immunocompetent hosts.
- A 58-year-old man with a chronic lower-extremity wound develops cellulitis. His clinician wants to decide whether empiric coverage against methicillin-resistant Staphylococcus aureus is warranted. Which single feature most strongly justifies adding methicillin-resistant Staphylococcus aureus coverage to the empiric regimen?
- Sharp demarcation of the erythema
- Involvement of the lower extremity rather than the upper extremity
- The patient reports mild pruritus over the area
- The presence of purulent drainage or a drainable abscess
Correct answer: The presence of purulent drainage or a drainable abscess
Purulent drainage or a drainable abscess is the feature that most justifies methicillin-resistant Staphylococcus aureus coverage. Purulent skin and soft tissue infections are commonly staphylococcal, including methicillin-resistant strains, so they warrant agents such as trimethoprim-sulfamethoxazole or doxycycline after drainage. Sharp demarcation actually suggests streptococcal erysipelas, and the affected limb or mild pruritus does not predict the organism. The purulence is the decisive clue.
- A 50-year-old man with a prosthetic aortic valve develops infective endocarditis caused by methicillin-resistant Staphylococcus aureus. After surgical evaluation, which antibiotic is the recommended backbone for treating methicillin-resistant staphylococcal prosthetic valve endocarditis?
- Vancomycin
- Ceftriaxone
- Ampicillin
- Azithromycin
Correct answer: Vancomycin
Vancomycin is the recommended backbone for methicillin-resistant staphylococcal endocarditis, and for prosthetic valve disease it is typically combined with rifampin and gentamicin. Ceftriaxone and ampicillin are beta-lactams that do not reliably cover methicillin-resistant Staphylococcus aureus. Azithromycin is a macrolide with no role in endocarditis treatment. The need to cover a resistant staphylococcus on a prosthetic valve makes vancomycin the cornerstone.
- A 55-year-old man is being evaluated for possible infective endocarditis. Blood cultures and an echocardiogram are pending. The team applies a validated diagnostic framework. Which diagnostic criteria are used to classify the likelihood of infective endocarditis based on major and minor findings?
- The Wells criteria
- The modified Duke criteria
- The Light criteria
- The Ranson criteria
Correct answer: The modified Duke criteria
The modified Duke criteria are used to classify the likelihood of infective endocarditis, combining major criteria such as typical organisms in blood cultures and echocardiographic evidence with minor criteria such as fever, predisposing conditions, and vascular phenomena. The Wells criteria estimate venous thromboembolism risk, the Light criteria distinguish exudative from transudative pleural effusions, and the Ranson criteria assess pancreatitis severity. Only the Duke framework addresses endocarditis.
- A 34-year-old man with newly diagnosed HIV and a CD4 count of 90 cells per microliter is started on antiretroviral therapy. Which opportunistic infection prophylaxis is indicated at this CD4 count to prevent Pneumocystis pneumonia?
- Trimethoprim-sulfamethoxazole
- Fluconazole
- Azithromycin weekly
- Valganciclovir
Correct answer: Trimethoprim-sulfamethoxazole
Trimethoprim-sulfamethoxazole is indicated for Pneumocystis pneumonia prophylaxis once the CD4 count falls below 200 cells per microliter, as in this patient at 90. Weekly azithromycin is used for Mycobacterium avium complex prophylaxis at much lower counts and is no longer routinely needed when antiretroviral therapy is promptly started, fluconazole is not standard primary prophylaxis at this count, and valganciclovir is reserved for cytomegalovirus disease. The decisive trigger here is the CD4 below 200.
- A 40-year-old woman with HIV that has been virologically suppressed for over a year on antiretroviral therapy now has a sustained CD4 count of 260 cells per microliter, up from a nadir of 80. She has been taking trimethoprim-sulfamethoxazole for Pneumocystis prophylaxis. What is the appropriate next step regarding her Pneumocystis prophylaxis?
- Continue prophylaxis indefinitely regardless of CD4 recovery
- Switch to lifelong azithromycin
- Double the dose of trimethoprim-sulfamethoxazole
- Discontinue prophylaxis because the CD4 count is sustained above 200
Correct answer: Discontinue prophylaxis because the CD4 count is sustained above 200
Discontinuing prophylaxis is appropriate because Pneumocystis prophylaxis can be stopped once the CD4 count is sustained above 200 cells per microliter for at least three months on effective therapy. Continuing it indefinitely is unnecessary once immune reconstitution occurs, switching to azithromycin targets a different organism, and increasing the dose has no rationale. Immune recovery on antiretroviral therapy is what permits safe discontinuation.
- A 65-year-old man who completed therapy for an initial episode of Clostridioides difficile infection develops a first recurrence three weeks later with watery diarrhea. He was originally treated with oral vancomycin. Which approach is most appropriate for this first recurrence?
- Repeat the identical short course of oral metronidazole
- Treat with fidaxomicin or a prolonged tapered-and-pulsed oral vancomycin regimen
- Begin lifelong daily oral vancomycin
- Start intravenous vancomycin
Correct answer: Treat with fidaxomicin or a prolonged tapered-and-pulsed oral vancomycin regimen
Fidaxomicin or a tapered-and-pulsed oral vancomycin regimen is appropriate for a first recurrence of Clostridioides difficile infection. Metronidazole is no longer favored even for initial disease and is inadequate for recurrence. Lifelong daily vancomycin is not standard, and intravenous vancomycin does not achieve luminal colonic concentrations and is ineffective for this infection. Targeting the recurrence with fidaxomicin or a vancomycin taper reflects current guidance.
- A clinician is reviewing testing for suspected Clostridioides difficile infection in a patient with new diarrhea. Which factor must be present before stool is tested, to avoid detecting asymptomatic colonization?
- Clinically significant diarrhea, generally three or more unformed stools in 24 hours
- Resolution of diarrhea before sampling
- A formed stool sample collected after antibiotics are stopped
- A negative abdominal imaging study
Correct answer: Clinically significant diarrhea, generally three or more unformed stools in 24 hours
Clinically significant diarrhea, typically three or more unformed stools in 24 hours, must be present before testing for Clostridioides difficile. Testing formed stool or patients without diarrhea detects colonization rather than infection and leads to overtreatment, which is why guidelines discourage it. Imaging is not a prerequisite for testing. Restricting testing to symptomatic patients with true diarrhea is the key principle.
- A 35-year-old man with a positive interferon-gamma release assay, no symptoms, and a normal chest radiograph is diagnosed with latent tuberculosis infection after active disease is excluded. Which is an acceptable shorter-course treatment regimen for latent tuberculosis?
- Twelve months of daily ethambutol
- Two weeks of azithromycin
- Six months of daily streptomycin
- Three months of weekly isoniazid plus rifapentine
Correct answer: Three months of weekly isoniazid plus rifapentine
Three months of once-weekly isoniazid plus rifapentine is an accepted, preferred shorter-course regimen for latent tuberculosis, alongside options such as four months of daily rifampin. Twelve months of ethambutol, two weeks of azithromycin, and six months of streptomycin are not latent tuberculosis regimens. The combination of isoniazid and rifapentine over three months reflects modern guideline-endorsed treatment.
- A patient on standard four-drug therapy for active pulmonary tuberculosis develops new joint pains, and laboratory testing shows an elevated serum uric acid. Which drug in the regimen is the most likely cause of asymptomatic hyperuricemia and arthralgias?
- Ethambutol
- Pyrazinamide
- Isoniazid
- Rifampin
Correct answer: Pyrazinamide
Pyrazinamide is the most likely cause; it reduces renal urate excretion and characteristically produces hyperuricemia, sometimes with arthralgias. Ethambutol is classically associated with optic neuritis, isoniazid with peripheral neuropathy and hepatotoxicity, and rifampin with orange body fluids and drug interactions. The hyperuricemia and joint pains point specifically to pyrazinamide.
- A 68-year-old man develops fever, headache, and progressive confusion in late summer. Cerebrospinal fluid shows a lymphocytic pleocytosis, and he reports recent mosquito bites in an area with reported cases. Which arboviral infection is the most likely cause of his meningoencephalitis?
- West Nile virus infection
- Rotavirus infection
- Influenza A infection
- Respiratory syncytial virus infection
Correct answer: West Nile virus infection
West Nile virus infection is the most likely cause. It is a mosquito-borne flavivirus that peaks in late summer and can cause meningoencephalitis, especially in older adults, with a lymphocytic cerebrospinal fluid profile and occasional flaccid paralysis; management is supportive. Influenza causes respiratory illness, while rotavirus and respiratory syncytial virus do not cause arboviral meningoencephalitis. The seasonal mosquito exposure and neuroinvasive picture point to West Nile virus.
- A 72-year-old man with diabetes develops fever and meningismus, and cerebrospinal fluid analysis is consistent with bacterial meningitis. Because of his age, empiric coverage is broadened beyond the typical agents. Which organism, particularly important at the extremes of age and in immunocompromised hosts, prompts the addition of ampicillin to empiric therapy?
- Listeria monocytogenes
- Haemophilus ducreyi
- Neisseria gonorrhoeae
- Bordetella pertussis
Correct answer: Listeria monocytogenes
Listeria monocytogenes is the organism that prompts adding ampicillin, because cephalosporins do not cover it and it is an important cause of bacterial meningitis in adults over 50 and in immunocompromised patients. Neisseria gonorrhoeae and Haemophilus ducreyi cause sexually transmitted disease, and Bordetella pertussis causes whooping cough. The age-related Listeria risk is what drives the ampicillin addition.
- A 45-year-old man undergoing chemotherapy develops a single fever of 38.5 degrees Celsius and is found to have an absolute neutrophil count of 300 cells per microliter. He appears stable. What is the most appropriate immediate management of this febrile neutropenia?
- Withhold antibiotics until a source is confirmed on imaging
- Start oral acyclovir alone and observe
- Administer a single dose of acetaminophen and discharge
- Obtain blood cultures and start empiric broad-spectrum antibacterial therapy promptly
Correct answer: Obtain blood cultures and start empiric broad-spectrum antibacterial therapy promptly
Obtaining cultures and starting empiric broad-spectrum antibacterial therapy promptly is correct; febrile neutropenia is a medical emergency, and high-risk patients typically receive an antipseudomonal beta-lactam such as cefepime or piperacillin-tazobactam without delay. Waiting for imaging, using acyclovir alone, or discharging the patient could be fatal because gram-negative bacteremia can progress rapidly in neutropenic hosts. Empiric antibacterial coverage is the priority.
- A 30-year-old man underwent splenectomy after trauma several years ago. To reduce his lifelong risk of overwhelming infection, vaccination against which group of organisms is the highest priority in asplenic patients?
- Encapsulated bacteria such as Streptococcus pneumoniae, Haemophilus influenzae type b, and Neisseria meningitidis
- Rotavirus
- Hepatitis A virus only
- Tetanus toxoid alone
Correct answer: Encapsulated bacteria such as Streptococcus pneumoniae, Haemophilus influenzae type b, and Neisseria meningitidis
Vaccination against encapsulated bacteria, namely Streptococcus pneumoniae, Haemophilus influenzae type b, and Neisseria meningitidis, is the highest priority because the spleen is critical for clearing encapsulated organisms and asplenic patients are at risk for overwhelming post-splenectomy sepsis. Hepatitis A, rotavirus, and tetanus vaccines do not address the encapsulated-organism risk that defines asplenia. Protecting against these three encapsulated pathogens is the cornerstone of asplenic care.
- A 55-year-old farmer in the Ohio River Valley develops several weeks of fever, cough, weight loss, and fatigue, and a chest radiograph shows mediastinal lymphadenopathy with pulmonary infiltrates. He has extensive exposure to soil contaminated with bird and bat droppings. Which endemic fungal infection is the most likely cause?
- Aspergillosis
- Histoplasmosis
- Candidiasis
- Mucormycosis
Correct answer: Histoplasmosis
Histoplasmosis is the most likely cause. Histoplasma capsulatum is endemic to the Ohio and Mississippi River valleys and is associated with exposure to soil enriched by bird and bat droppings, producing a subacute pulmonary illness with mediastinal adenopathy. Invasive aspergillosis and mucormycosis chiefly affect immunocompromised hosts, and candidiasis is not an inhalational endemic mycosis. The geography and exposure strongly indicate histoplasmosis.
- A 50-year-old man who recently traveled through Arizona and the San Joaquin Valley of California develops fever, cough, fatigue, and erythema nodosum, with a chest radiograph showing a focal infiltrate. Which endemic fungal infection should be strongly considered given his desert southwest exposure?
- Cryptococcosis
- Pneumocystis pneumonia
- Nocardiosis
- Coccidioidomycosis
Correct answer: Coccidioidomycosis
Coccidioidomycosis should be strongly considered. Coccidioides species are endemic to the desert southwest, including Arizona and California's San Joaquin Valley, and cause a flu-like pulmonary illness sometimes accompanied by erythema nodosum, often called Valley fever. Cryptococcosis and Pneumocystis pneumonia are more typical of immunocompromised hosts, and nocardiosis has a different presentation and risk profile. The southwestern exposure with erythema nodosum points to coccidioidomycosis.
- A 60-year-old man with neutropenia from leukemia develops candidemia, with Candida species growing in blood cultures. Which class of antifungal agents is the recommended first-line therapy for candidemia in most patients?
- Oral nystatin
- Topical clotrimazole
- Griseofulvin
- An echinocandin such as micafungin or caspofungin
Correct answer: An echinocandin such as micafungin or caspofungin
An echinocandin such as micafungin or caspofungin is recommended first-line for candidemia, given broad activity against Candida species including many azole-resistant strains and a favorable safety profile. Oral nystatin and topical clotrimazole treat only mucocutaneous candidiasis and do not reach the bloodstream, and griseofulvin treats dermatophytes, not Candida. Systemic echinocandin therapy is the standard for bloodstream Candida infection.
- A 28-year-old woman who is 14 weeks pregnant is found on routine prenatal screening to have asymptomatic bacteriuria with a significant colony count. What is the most appropriate management?
- Withhold antibiotics because she has no symptoms
- Repeat the culture in the third trimester only
- Treat only if she develops fever
- Treat with a pregnancy-safe antibiotic to reduce the risk of pyelonephritis and complications
Correct answer: Treat with a pregnancy-safe antibiotic to reduce the risk of pyelonephritis and complications
Treating asymptomatic bacteriuria with a pregnancy-safe antibiotic is correct, because in pregnancy untreated bacteriuria carries a substantial risk of progressing to pyelonephritis and is linked to preterm birth and low birth weight. Pregnancy is one of the few situations in which asymptomatic bacteriuria warrants treatment, unlike most nonpregnant adults in whom it should not be treated. Waiting for symptoms or fever would forgo the proven benefit of treatment in pregnancy.
- A surgical team is preparing a patient for an elective procedure and wants to minimize surgical site infection. To be most effective, when should a single dose of prophylactic antibiotics generally be administered relative to the surgical incision?
- Within 60 minutes before the incision
- Only after the wound is closed
- Twenty-four hours before surgery
- When the patient first develops postoperative fever
Correct answer: Within 60 minutes before the incision
Surgical prophylaxis is most effective when administered within 60 minutes before the incision, so that adequate tissue concentrations are present at the time of contamination. Giving antibiotics only after closure, a full day before surgery, or waiting for postoperative fever fails to provide protection during the contamination window. Timely preincision dosing is the key principle of surgical antimicrobial prophylaxis.
- A 35-year-old man returns from a multi-week trip through rural sub-Saharan Africa and develops fever. He did not take malaria chemoprophylaxis. Beyond ordering blood smears, which initial step is most important in the febrile returning traveler to guide the differential diagnosis?
- Immediately begin empiric broad-spectrum antibiotics for all such patients
- Obtain a detailed travel itinerary, exposures, and incubation-period history
- Defer any workup until symptoms persist for two weeks
- Order only a chest radiograph and discharge
Correct answer: Obtain a detailed travel itinerary, exposures, and incubation-period history
Obtaining a detailed travel itinerary, exposures, and incubation-period history is most important, because the geography, activities, and timing relative to return narrow a broad differential that includes malaria, enteric fever, dengue, and rickettsial disease. Empiric antibiotics for everyone, delaying workup, or limiting evaluation to a chest radiograph would miss time-sensitive and serious diagnoses such as malaria. A structured travel and exposure history drives the workup.
- A 40-year-old man develops watery diarrhea, low-grade fever, and abdominal cramping a few days after consuming undercooked poultry. Stool studies identify a curved, motile, comma-shaped gram-negative rod that grows best at 42 degrees Celsius. Which organism is the most likely cause?
- Giardia lamblia
- Campylobacter jejuni
- Entamoeba histolytica
- Norovirus
Correct answer: Campylobacter jejuni
Campylobacter jejuni is the most likely cause, a curved gram-negative rod that grows at 42 degrees Celsius, is commonly acquired from undercooked poultry, and is a leading cause of bacterial gastroenteritis; it is also associated with later Guillain-Barre syndrome. Giardia and Entamoeba are protozoa with different morphology and risk factors, and norovirus is a virus, not a gram-negative rod. The microbiologic and exposure details point to Campylobacter.
- A 55-year-old man with cirrhosis eats raw shellfish and within two days develops fever, hypotension, and rapidly progressive hemorrhagic bullous skin lesions on the legs, with sepsis. Which organism is the most likely cause of this fulminant infection in a patient with liver disease?
- Clostridioides difficile
- Streptococcus pneumoniae
- Vibrio vulnificus
- Helicobacter pylori
Correct answer: Vibrio vulnificus
Vibrio vulnificus is the most likely cause; it is acquired from raw shellfish or seawater and causes fulminant sepsis with hemorrhagic bullae, especially in patients with cirrhosis or iron overload. Clostridioides difficile causes antibiotic-associated colitis, Streptococcus pneumoniae causes pneumonia and meningitis, and Helicobacter pylori causes peptic ulcer disease. The shellfish exposure, liver disease, and hemorrhagic bullae are classic for Vibrio vulnificus.
- A 25-year-old immigrant who has not been vaccinated develops high fever, cough, coryza, conjunctivitis, and then a descending maculopapular rash. Examination reveals small white spots with a bluish center on the buccal mucosa. Which infection is the most likely diagnosis?
- Influenza
- Acute HIV infection
- Measles
- Scarlet fever
Correct answer: Measles
Measles is the most likely diagnosis. The triad of cough, coryza, and conjunctivitis followed by a descending rash, along with Koplik spots, which are the pathognomonic buccal white lesions, is classic for measles in an unvaccinated person. Influenza lacks Koplik spots and the descending rash, acute HIV produces a nonspecific mononucleosis-like illness, and scarlet fever causes a sandpaper rash with strawberry tongue rather than Koplik spots. The Koplik spots clinch measles.
- A 60-year-old hospitalized patient has a central venous catheter and develops new fever and rigors. Blood cultures drawn simultaneously from the catheter and a peripheral vein both grow Staphylococcus aureus, with the catheter sample turning positive substantially earlier. After deciding the catheter is the source, what is the most appropriate management of the catheter in Staphylococcus aureus catheter-related bloodstream infection?
- Leave the catheter in place and treat through it
- Exchange the catheter over a guidewire at the same site
- Lock the catheter with heparin alone
- Remove the infected catheter
Correct answer: Remove the infected catheter
Removing the infected catheter is most appropriate, because Staphylococcus aureus catheter-related bloodstream infection should prompt catheter removal along with systemic antibiotics to control the source and reduce complications such as endocarditis. Leaving the catheter, exchanging it over a guidewire at the same site, or relying on a heparin lock does not adequately address staphylococcal device infection. Source control through removal is the standard.
- A 30-year-old man develops a painful vesicular rash limited to one thoracic dermatome with no crossing of the midline, consistent with herpes zoster. He presents within 48 hours of onset. What is the primary benefit of starting antiviral therapy such as valacyclovir promptly in this setting?
- Eradicating the latent virus from the dorsal root ganglia
- Reducing the severity and duration of the acute episode and lowering the risk of complications
- Preventing all future episodes permanently
- Curing established postherpetic neuralgia that is already present
Correct answer: Reducing the severity and duration of the acute episode and lowering the risk of complications
The primary benefit is reducing the severity and duration of the acute herpes zoster episode and lowering the risk of complications when started within about 72 hours of rash onset. Antivirals do not eradicate the latent virus, which persists in the dorsal root ganglia, nor do they guarantee no future episodes or cure established postherpetic neuralgia. Early antiviral treatment modifies the acute illness, which is the key reason to start promptly.
- A 67-year-old immunocompetent adult is seen for routine preventive care. To prevent shingles and its complications, which vaccine is currently recommended for immunocompetent adults aged 50 years and older?
- A single dose of the live attenuated influenza vaccine
- The recombinant zoster vaccine given as a two-dose series
- The hepatitis B vaccine series
- No vaccine, because shingles cannot be prevented
Correct answer: The recombinant zoster vaccine given as a two-dose series
The recombinant zoster vaccine given as a two-dose series is recommended for immunocompetent adults 50 years and older and is more effective and durable than the older live vaccine. The live attenuated influenza vaccine prevents influenza, not zoster, and the hepatitis B series addresses a different pathogen. Shingles is preventable with the recombinant zoster vaccine, making the two-dose series the correct preventive choice.
- A 35-year-old man hiking in the upper Midwest in summer develops fever, fatigue, headache, and myalgias. Laboratory studies show leukopenia, thrombocytopenia, and elevated transaminases, and a blood smear reveals morulae within granulocytes. Which tick-borne infection is the most likely cause?
- Lyme disease
- Babesiosis
- Human granulocytic anaplasmosis
- Rocky Mountain spotted fever
Correct answer: Human granulocytic anaplasmosis
Human granulocytic anaplasmosis is the most likely cause; it presents with a nonspecific febrile illness, leukopenia, thrombocytopenia, and transaminitis, with morulae seen in granulocytes, and is treated with doxycycline. Lyme disease classically causes erythema migrans, babesiosis causes hemolysis with intraerythrocytic parasites, and Rocky Mountain spotted fever features a rash spreading from wrists and ankles. The granulocytic morulae and cytopenias indicate anaplasmosis.
- A 50-year-old asplenic man develops high fever, fatigue, dark urine, and jaundice after a summer in coastal New England. Laboratory studies show hemolytic anemia, and a blood smear reveals intraerythrocytic ring forms with occasional tetrad arrangements. Which tick-borne infection is the most likely cause?
- Influenza
- Streptococcal pharyngitis
- Babesiosis
- Tuberculosis
Correct answer: Babesiosis
Babesiosis is the most likely cause; Babesia microti is a tick-borne intraerythrocytic parasite endemic to the northeastern United States that causes hemolytic anemia with characteristic ring forms and the classic Maltese cross tetrad, and it is especially severe in asplenic patients. Influenza, streptococcal pharyngitis, and tuberculosis do not produce intraerythrocytic parasites or this hemolytic picture. The smear findings and asplenia point to babesiosis.
- A 30-year-old man who recently returned from freshwater rafting in a tropical region, with reported flooding, develops fever, severe myalgias, conjunctival suffusion, and jaundice with acute kidney injury. Which spirochetal infection acquired through water contaminated by animal urine is the most likely cause?
- Legionellosis
- Influenza
- Leptospirosis
- Histoplasmosis
Correct answer: Leptospirosis
Leptospirosis is the most likely cause; it is a spirochetal infection acquired through freshwater or soil contaminated by animal urine, classically presenting with fever, myalgias, conjunctival suffusion, and in severe Weil disease, jaundice and kidney injury. Legionellosis is a respiratory infection, influenza does not cause conjunctival suffusion with hepatorenal involvement, and histoplasmosis is a fungal pulmonary infection. The water exposure and conjunctival suffusion with hepatorenal disease point to leptospirosis.
- A 40-year-old slaughterhouse worker develops an acute febrile illness with atypical pneumonia, and serologic testing later confirms a zoonotic infection associated with exposure to parturient livestock and their birth products. Which organism is the most likely cause of this Q fever presentation?
- Mycobacterium tuberculosis
- Neisseria meningitidis
- Candida albicans
- Coxiella burnetii
Correct answer: Coxiella burnetii
Coxiella burnetii is the most likely cause of Q fever, a zoonosis acquired by inhaling aerosols from parturient livestock, presenting with an acute febrile illness, atypical pneumonia, or hepatitis, and treated with doxycycline. Mycobacterium tuberculosis, Neisseria meningitidis, and Candida albicans do not fit this livestock-associated zoonotic syndrome. The occupational exposure to birthing animals identifies Coxiella burnetii.
- A 45-year-old man with poorly controlled HIV and a CD4 count of 50 cells per microliter develops several weeks of headache, low-grade fever, and malaise. Lumbar puncture shows elevated opening pressure, and cryptococcal antigen is positive in the cerebrospinal fluid. Which combination is the recommended initial induction therapy for cryptococcal meningitis?
- Oral fluconazole monotherapy at a low dose
- Vancomycin plus ceftriaxone
- Liposomal amphotericin B plus flucytosine
- Acyclovir alone
Correct answer: Liposomal amphotericin B plus flucytosine
Liposomal amphotericin B plus flucytosine is the recommended induction therapy for cryptococcal meningitis, followed by fluconazole consolidation and maintenance, along with management of elevated intracranial pressure through serial lumbar punctures. Low-dose fluconazole monotherapy is inadequate for induction, vancomycin plus ceftriaxone targets bacterial meningitis, and acyclovir treats herpes infections. The amphotericin and flucytosine combination is the standard induction.
- A 30-year-old man with advanced untreated HIV and a CD4 count of 60 cells per microliter develops several weeks of headache and new-onset focal neurologic deficits. Brain imaging shows multiple ring-enhancing lesions, and serology is positive for Toxoplasma. Which is the recommended first-line treatment for cerebral toxoplasmosis?
- Oral vancomycin
- Isoniazid monotherapy
- Single-agent metronidazole
- Pyrimethamine plus sulfadiazine with leucovorin
Correct answer: Pyrimethamine plus sulfadiazine with leucovorin
Pyrimethamine plus sulfadiazine with leucovorin is the recommended first-line treatment for cerebral toxoplasmosis, which classically presents with multiple ring-enhancing brain lesions in patients with advanced HIV; leucovorin is added to mitigate marrow toxicity from pyrimethamine. Oral vancomycin treats Clostridioides difficile, isoniazid treats tuberculosis, and metronidazole alone does not treat Toxoplasma. The pyrimethamine and sulfadiazine combination is standard.
- A 38-year-old returning traveler from Southeast Asia develops fever, headache, and severe retro-orbital pain, with diffuse myalgias and a maculopapular rash; laboratory studies show leukopenia and thrombocytopenia. Which class of medication should specifically be avoided during the acute febrile phase because of bleeding risk in this mosquito-borne illness?
- Nonsteroidal anti-inflammatory drugs and aspirin
- Acetaminophen
- Oral rehydration solution
- Antiemetics
Correct answer: Nonsteroidal anti-inflammatory drugs and aspirin
Nonsteroidal anti-inflammatory drugs and aspirin should be avoided during acute dengue because of the risk of hemorrhage and platelet dysfunction in a disease already marked by thrombocytopenia and capillary leak; acetaminophen is preferred for fever and pain. Oral rehydration and antiemetics are supportive and appropriate. Avoiding antiplatelet and nonsteroidal agents is the key safety principle in suspected dengue.
- A 45-year-old man with poorly controlled diabetes and ketoacidosis develops facial pain, black necrotic eschar on the nasal turbinates and palate, and orbital swelling. Which invasive fungal infection should be suspected immediately, given its propensity for angioinvasion in this host?
- Oral candidiasis
- Tinea versicolor
- Mucormycosis
- Dermatophytosis
Correct answer: Mucormycosis
Mucormycosis should be suspected immediately. Rhino-orbital-cerebral mucormycosis is an angioinvasive mold infection that classically affects patients with diabetic ketoacidosis or immunosuppression, producing black necrotic eschars and rapid tissue invasion, and it requires urgent surgical debridement and amphotericin B. Oral candidiasis, tinea versicolor, and dermatophytosis are superficial and not angioinvasive. The ketoacidosis and necrotic eschar point to mucormycosis.
- A 25-year-old immunocompetent adult develops sudden fever, low back and joint pains, and a fine erythematous rash, and the clinician needs to update routine immunizations. Which live attenuated vaccine is contraindicated in pregnancy and in significantly immunocompromised patients?
- Recombinant hepatitis B vaccine
- Measles, mumps, and rubella vaccine
- Inactivated influenza vaccine
- Tetanus, diphtheria, and pertussis vaccine
Correct answer: Measles, mumps, and rubella vaccine
The measles, mumps, and rubella vaccine is a live attenuated vaccine that is contraindicated in pregnancy and in significantly immunocompromised patients because of the risk of disease from the vaccine strain. The recombinant hepatitis B vaccine, the inactivated influenza vaccine, and the tetanus-diphtheria-pertussis vaccine are not live and are generally safe in these populations. The live nature of the measles-mumps-rubella vaccine drives the contraindication.
- A 33-year-old man returns from rural travel and develops one week of rising fevers, headache, abdominal pain, and constipation, with relative bradycardia and faint rose-colored spots on the trunk. Blood cultures are obtained. Which organism is the most likely cause of this enteric fever syndrome?
- Norovirus
- Rotavirus
- Salmonella enterica serotype Typhi
- Staphylococcus epidermidis
Correct answer: Salmonella enterica serotype Typhi
Salmonella enterica serotype Typhi is the most likely cause; typhoid fever classically presents with stepwise fevers, abdominal symptoms with constipation or diarrhea, relative bradycardia, and rose spots, and is confirmed by blood culture. Norovirus and rotavirus cause acute self-limited gastroenteritis, and Staphylococcus epidermidis is a skin commensal and common contaminant. The travel history with rose spots and relative bradycardia identifies typhoid fever.
- A 70-year-old nursing home resident develops watery diarrhea during an outbreak affecting several residents and staff over a short period, with nausea and vomiting and a brief, self-limited course lasting about two days. Which pathogen is the most likely cause of this highly contagious outbreak of acute gastroenteritis?
- Mycobacterium tuberculosis
- Treponema pallidum
- Norovirus
- Plasmodium falciparum
Correct answer: Norovirus
Norovirus is the most likely cause; it is the leading cause of explosive, highly contagious gastroenteritis outbreaks in closed settings such as nursing homes and cruise ships, producing short, self-limited vomiting and diarrhea, with management focused on hydration and contact precautions. Mycobacterium tuberculosis, Treponema pallidum, and Plasmodium falciparum do not cause acute outbreak gastroenteritis. The institutional outbreak with brief, self-limited illness points to norovirus.
- A 65-year-old man receiving long-term corticosteroids develops a subacute pneumonia with cavitation, and a Gram stain of sputum shows branching, beaded, weakly acid-fast filamentous gram-positive rods; he also has a brain lesion. Which organism is the most likely cause of this pulmonary infection with central nervous system spread?
- Streptococcus pyogenes
- Escherichia coli
- Nocardia species
- Bacteroides fragilis
Correct answer: Nocardia species
Nocardia species are the most likely cause; nocardiosis affects immunocompromised hosts, including those on chronic corticosteroids, presenting as a cavitary pneumonia with a tendency to disseminate to the brain, and the organism appears as branching, beaded, weakly acid-fast filamentous gram-positive rods treated with trimethoprim-sulfamethoxazole. Streptococcus pyogenes, Escherichia coli, and Bacteroides fragilis do not show this morphology or this pulmonary-to-brain pattern. The filamentous weakly acid-fast appearance identifies Nocardia.
- A 34-year-old man with newly diagnosed HIV is started on antiretroviral therapy. Which laboratory parameter is the best measure of the long-term success of therapy in suppressing viral replication?
- A sustained undetectable plasma HIV RNA viral load
- A normal serum sodium level
- A negative HIV antibody test
- A normal serum creatinine
Correct answer: A sustained undetectable plasma HIV RNA viral load
A sustained undetectable plasma HIV RNA viral load is the best measure of therapeutic success, because effective antiretroviral therapy is defined by viral suppression below the limit of detection, which then permits immune recovery reflected in rising CD4 counts. A normal sodium or creatinine reflects general health rather than viral control, and the HIV antibody test remains positive after infection regardless of treatment. Viral load is the direct marker of antiretroviral efficacy.
- A 60-year-old man with diabetes develops nonpurulent cellulitis of the leg with mild systemic signs but no abscess. He is admitted for intravenous therapy. Which intravenous antibiotic provides appropriate empiric coverage of beta-hemolytic streptococci for nonpurulent cellulitis?
- Oral fluconazole
- Intravenous metronidazole alone
- Intravenous acyclovir
- Intravenous cefazolin
Correct answer: Intravenous cefazolin
Intravenous cefazolin provides appropriate empiric coverage for nonpurulent cellulitis, which is predominantly streptococcal and also covers methicillin-susceptible staphylococci. Fluconazole is an antifungal, metronidazole covers only anaerobes, and acyclovir is an antiviral, none of which address the beta-hemolytic streptococci responsible for nonpurulent cellulitis. Cefazolin is a standard parenteral choice for this infection.
- A 52-year-old man with a native mitral valve has infective endocarditis, and blood cultures grow viridans group streptococci that are highly penicillin-susceptible. Which antibiotic class is the recommended backbone for treating penicillin-susceptible streptococcal native valve endocarditis?
- An oral fluoroquinolone
- Penicillin or ceftriaxone
- Oral metronidazole
- An inhaled aminoglycoside
Correct answer: Penicillin or ceftriaxone
Penicillin or ceftriaxone is the recommended backbone for penicillin-susceptible viridans group streptococcal native valve endocarditis, often given for several weeks and sometimes combined with gentamicin to shorten therapy. Oral fluoroquinolones and oral metronidazole are not standard endocarditis therapy, and aminoglycosides are given intravenously as adjuncts rather than inhaled. The penicillin susceptibility makes a penicillin or ceftriaxone regimen the standard.
- A patient with active pulmonary tuberculosis is started on standard four-drug therapy including isoniazid. To reduce a common neurologic adverse effect of isoniazid, which supplement should be co-administered?
- Vitamin B12
- Folic acid
- Pyridoxine, which is vitamin B6
- Vitamin D
Correct answer: Pyridoxine, which is vitamin B6
Pyridoxine, vitamin B6, should be co-administered to prevent isoniazid-induced peripheral neuropathy, which results from isoniazid interfering with pyridoxine metabolism. Vitamin B12 and folic acid address other anemias, and vitamin D addresses bone metabolism, none of which prevent isoniazid neuropathy. Pyridoxine supplementation is the targeted preventive measure during isoniazid therapy.
- A 63-year-old man with diabetes who is otherwise healthy presents to update his immunizations. He has never received any pneumococcal vaccine and his diabetes is his only chronic condition. According to current adult immunization recommendations, how does his diabetes affect the age at which pneumococcal vaccination is advised?
- Diabetes has no effect, so he should wait until the routine older-adult age
- Diabetes is a chronic condition that makes pneumococcal vaccination indicated even before the routine older-adult age
- Diabetes is a contraindication to pneumococcal vaccination
- Diabetes requires only the polysaccharide vaccine and never a conjugate vaccine
Correct answer: Diabetes is a chronic condition that makes pneumococcal vaccination indicated even before the routine older-adult age
Diabetes is a chronic condition that makes pneumococcal vaccination indicated even before the routine older-adult age because adult schedules recommend pneumococcal vaccination for younger adults who have qualifying chronic illnesses such as diabetes, rather than waiting for the age-based trigger. The chronic condition advances eligibility. Saying diabetes has no effect ignores the risk-based recommendation, calling it a contraindication is incorrect since the vaccine is encouraged, and restricting him to only the polysaccharide product misstates the current conjugate-based approach.
- A 70-year-old woman with well-controlled hypertension and good exercise tolerance is scheduled for elective cataract surgery under local anesthesia. She has no cardiac symptoms. Regarding routine preoperative laboratory and cardiac testing for this procedure, which approach is most appropriate?
- Order a full panel of preoperative labs, an electrocardiogram, and a stress test for completeness
- Require coronary angiography because she is over 65
- Proceed without routine preoperative testing because cataract surgery is very low risk
- Cancel the procedure unless a cardiologist clears her in person
Correct answer: Proceed without routine preoperative testing because cataract surgery is very low risk
Proceeding without routine preoperative testing is most appropriate because cataract surgery is a very low-risk procedure for which routine preoperative laboratory studies, electrocardiograms, and cardiac stress testing do not improve outcomes in an asymptomatic patient. Avoiding low-value testing is the recommended approach. Ordering a comprehensive panel for completeness, requiring angiography based on age alone, and mandating in-person cardiology clearance all add cost and delay without benefit for this minimal-risk operation.
- A clinician reads a meta-analysis pooling several randomized trials of a blood pressure drug. The forest plot shows a high I-squared statistic. What does this finding most directly indicate about the included studies?
- The pooled treatment effect is statistically significant
- There is substantial statistical heterogeneity among the study results
- The studies have a low risk of publication bias
- The sample size of each trial was adequate
Correct answer: There is substantial statistical heterogeneity among the study results
A high I-squared statistic most directly indicates substantial statistical heterogeneity among the study results because I-squared estimates the proportion of variability across studies that is due to genuine differences rather than chance, and a high value signals that the trials differ meaningfully. It quantifies inconsistency, not significance. A high I-squared does not tell you whether the pooled effect is significant, says nothing about publication bias, and does not reflect whether individual trials were adequately powered.
- A 55-year-old man is found unresponsive and pulseless in a hospital corridor. A passerby clinician confirms no pulse and no normal breathing. According to current basic life support priorities for an adult in cardiac arrest, what is the most important immediate action?
- Begin high-quality chest compressions and activate the emergency response system
- Spend two minutes checking the airway before any compressions
- Administer rescue breaths first and delay compressions
- Wait for a defibrillator before doing anything else
Correct answer: Begin high-quality chest compressions and activate the emergency response system
Beginning high-quality chest compressions and activating the emergency response system is the most important immediate action because in adult cardiac arrest, prompt activation of help and early, effective compressions are the priorities that most influence survival. Compressions maintain perfusion until definitive care arrives. Spending two minutes on the airway delays circulation, leading with rescue breaths reverses the current compression-first sequence for adults, and waiting passively for a defibrillator wastes critical time when compressions can start immediately.
- A 48-year-old construction worker reports that the same insurer denies coverage for a medication his physician believes is the best option, requiring a different drug be tried first. The physician completes paperwork documenting why the preferred agent is needed before the insurer will approve it. Which administrative process does this describe?
- Medication reconciliation at a care transition
- Therapeutic substitution by the pharmacy
- Prior authorization required by the payer
- A formulary exclusion appeal to a licensing board
Correct answer: Prior authorization required by the payer
Prior authorization required by the payer is the process described because it is the insurer-driven requirement that a clinician justify and obtain approval for a specific medication, often after a step-therapy requirement, before coverage is granted. It is an administrative gate controlled by the payer. Medication reconciliation compares medication lists at transitions, therapeutic substitution is a pharmacy swap to an equivalent agent, and the scenario involves the insurer rather than an appeal to a licensing board.
- A 76-year-old man with metastatic cancer has decided he wants comfort-focused care and no resuscitation. His clinician documents this discussion thoroughly. Months later he is admitted for an unrelated, fully reversible urinary tract infection and is alert and clearly states he wants antibiotics and supportive treatment. How should his do-not-resuscitate status affect the treatment of this infection?
- His do-not-resuscitate order means all active treatments, including antibiotics, must be withheld
- His do-not-resuscitate order applies only to attempted resuscitation in cardiac or respiratory arrest and does not preclude treating the infection
- His do-not-resuscitate order must be revoked entirely before any antibiotic can be given
- His do-not-resuscitate order automatically transfers all decisions to the family
Correct answer: His do-not-resuscitate order applies only to attempted resuscitation in cardiac or respiratory arrest and does not preclude treating the infection
His do-not-resuscitate order applies only to attempted resuscitation in cardiac or respiratory arrest and does not preclude treating the infection, because a do-not-resuscitate order limits only cardiopulmonary resuscitation and does not by itself restrict other indicated, goal-concordant care such as antibiotics for a reversible infection. The order is narrow in scope. It does not require withholding all active treatment, does not need to be revoked to give antibiotics, and does not strip a capacitated patient of his own decision-making by handing choices to the family.
- A 58-year-old man undergoing a preoperative evaluation for elective major vascular surgery is found to have an active cardiac condition. Which of the following is considered an active cardiac condition that warrants evaluation and management before proceeding with elective noncardiac surgery?
- Well-controlled hypertension on a single agent
- A remote myocardial infarction five years ago with no current symptoms
- Decompensated heart failure with worsening dyspnea and edema
- Stable hyperlipidemia treated with a statin
Correct answer: Decompensated heart failure with worsening dyspnea and edema
Decompensated heart failure with worsening dyspnea and edema is an active cardiac condition that warrants evaluation and management before elective noncardiac surgery because unstable, decompensated heart failure substantially raises perioperative risk and should be optimized first. Active instability takes priority over proceeding. Well-controlled hypertension, a remote asymptomatic infarction, and stable treated hyperlipidemia are chronic stable conditions rather than active states that mandate delay of an elective operation.
- A hospital introduces a checklist that pauses the team to confirm the patient's identity, the surgical site, and the planned procedure immediately before incision. After one year, wrong-site surgeries fall to zero. Which patient safety concept does this preprocedure checklist best exemplify?
- A standardized safety process designed to prevent never events
- A retrospective outcome audit of completed cases
- A cost-containment measure to shorten operating time
- A patient satisfaction survey of the surgical experience
Correct answer: A standardized safety process designed to prevent never events
The preprocedure checklist best exemplifies a standardized safety process designed to prevent never events because confirming identity, site, and procedure before incision is a proactive systems-based safeguard intended to eliminate catastrophic, preventable errors such as wrong-site surgery. It builds reliability into the workflow. It is not a retrospective outcome audit, it is not aimed at shortening operating time, and it differs fundamentally from a patient satisfaction survey, which measures experience rather than prevents harm.
- A 67-year-old woman who immigrated recently asks which vaccines she should receive now that she lives in the United States. She has documentation of a complete childhood series but no record of influenza or pneumococcal vaccination as an adult. Beyond influenza and pneumococcal vaccines, which additional vaccine is routinely recommended for adults at her age to prevent reactivation of a latent virus?
- Yellow fever vaccine for all older adults
- Recombinant zoster (shingles) vaccine
- Bacille Calmette-Guerin vaccine
- A repeat measles-mumps-rubella series
Correct answer: Recombinant zoster (shingles) vaccine
The recombinant zoster vaccine is routinely recommended because adult schedules advise zoster vaccination for adults at and beyond the recommended starting age to prevent shingles, the reactivation of latent varicella-zoster virus, making it appropriate for a 67-year-old. Her age meets the recommendation. Yellow fever vaccine is given only for travel to endemic areas, Bacille Calmette-Guerin is not part of routine United States adult immunization, and a repeat measles-mumps-rubella series is unnecessary for an adult with a documented complete childhood series.
- A 78-year-old man on a thiazide diuretic for hypertension is admitted with lethargy. Serum sodium is 122 mmol/L, he is clinically hypovolemic with dry mucous membranes and flat neck veins, urine sodium is 12 mmol/L, and his blood urea nitrogen to creatinine ratio is elevated. Which is the most appropriate initial treatment for his hyponatremia?
- Free water restriction alone
- A vasopressin receptor antagonist
- Isotonic saline volume repletion
- Hypertonic saline by continuous infusion without monitoring
Correct answer: Isotonic saline volume repletion
Isotonic saline volume repletion is correct because this patient has hypovolemic hypotonic hyponatremia, signaled by the physical findings of volume depletion, a low urine sodium showing avid renal sodium retention, and an elevated urea-to-creatinine ratio; restoring volume turns off the appropriate antidiuretic hormone response and allows water excretion. Water restriction alone treats euvolemic causes, vaptans are for euvolemic or hypervolemic states, and unmonitored hypertonic saline risks dangerous overcorrection.
- A 65-year-old man has a measured serum sodium of 125 mmol/L. He also has a markedly elevated blood glucose of 800 mg/dL from uncontrolled diabetes, and his measured serum osmolality is normal. Which best explains the low measured sodium?
- True hypotonic hyponatremia from water retention
- Cerebral salt wasting
- Pseudohyponatremia from severe hyperlipidemia
- Translocational (hypertonic) hyponatremia from hyperglycemia
Correct answer: Translocational (hypertonic) hyponatremia from hyperglycemia
Translocational hyponatremia from hyperglycemia is correct because a high extracellular glucose draws water out of cells, diluting the measured sodium even though the serum is hypertonic, so the corrected sodium is actually near normal. True hypotonic hyponatremia would show a low measured osmolality, pseudohyponatremia from lipids is an artifact with normal osmolality but no osmotic shift, and cerebral salt wasting causes volume depletion rather than a glucose effect.
- A 60-year-old woman with confirmed euvolemic hyponatremia from the syndrome of inappropriate antidiuretic hormone secretion has a serum sodium of 126 mmol/L and only mild symptoms. Her underlying cause cannot be removed immediately. Which is the most appropriate first-line management?
- Fluid restriction
- Intravenous dextrose in water
- A loop diuretic alone without sodium intake
- Rapid bolus of hypertonic saline
Correct answer: Fluid restriction
Fluid restriction is correct because in mildly symptomatic chronic SIADH the cornerstone of treatment is restricting free water intake so that intake falls below the obligate electrolyte-free water loss, allowing the sodium to rise slowly and safely. Dextrose in water adds free water and worsens the disorder, an isolated loop diuretic without solute is inadequate, and a hypertonic bolus is reserved for severe symptomatic hyponatremia.
- A 50-year-old man is brought to the emergency department with a witnessed generalized seizure and a serum sodium of 110 mmol/L that developed over the past day after a large water-drinking contest. Which is the most appropriate immediate treatment?
- Oral salt tablets
- Slow isotonic saline over 24 hours
- A small bolus of 3 percent hypertonic saline
- Strict fluid restriction alone
Correct answer: A small bolus of 3 percent hypertonic saline
A small bolus of 3 percent hypertonic saline is correct because acute severe symptomatic hyponatremia with seizures is a neurologic emergency that requires a prompt, modest rise in sodium using hypertonic saline to reduce cerebral edema, and the acute time course makes rapid initial correction safe. Oral salt and fluid restriction act too slowly, and isotonic saline raises the sodium too little for life-threatening symptoms.
- A 33-year-old woman with type 1 diabetes presents with Kussmaul breathing. Her arterial blood gas shows pH 7.20 and carbon dioxide partial pressure of 22 mmHg, with bicarbonate of 9 mmol/L. Using the expected compensation for a metabolic acidosis, how should the respiratory response be characterized?
- No compensation has occurred
- Superimposed primary respiratory acidosis
- Superimposed primary respiratory alkalosis
- Appropriate respiratory compensation
Correct answer: Appropriate respiratory compensation
Appropriate respiratory compensation is correct because the Winter formula predicts an expected carbon dioxide of about 21 to 25 mmHg for a bicarbonate of 9, and the measured value of 22 falls within that range, indicating the lungs are compensating as expected for the metabolic acidosis. A measured carbon dioxide above the range would mean a concurrent respiratory acidosis, a value below it would mean a concurrent respiratory alkalosis, and the low carbon dioxide here proves compensation has occurred.
- A 45-year-old man with chronic diarrhea has a serum sodium of 140, chloride 115, and bicarbonate of 15 mmol/L, with an arterial pH of 7.30. His urine anion gap is negative. Which acid-base disorder is present and what does the urine finding indicate?
- High anion gap acidosis from lactate
- Normal anion gap acidosis with appropriate renal acid excretion
- Metabolic alkalosis from volume contraction
- Normal anion gap acidosis from distal renal tubular acidosis
Correct answer: Normal anion gap acidosis with appropriate renal acid excretion
Normal anion gap acidosis with appropriate renal acid excretion is correct because the serum anion gap of 10 is normal, diarrhea causes gastrointestinal bicarbonate loss, and a negative urine anion gap indicates the kidney is excreting ammonium normally to compensate. A high gap would point to lactate or ketoacids, alkalosis would raise the bicarbonate, and distal renal tubular acidosis produces a positive urine anion gap from impaired ammonium excretion.
- A 24-year-old woman is found to have hypokalemia, metabolic alkalosis, low blood pressure, and a high urine chloride, with normal renin and aldosterone-driven physiology but no diuretic use detected. Genetic testing reveals a defect in the sodium-potassium-2-chloride transporter in the loop of Henle. Which inherited tubular disorder is this?
- Gitelman syndrome
- Liddle syndrome
- Bartter syndrome
- Type 1 distal renal tubular acidosis
Correct answer: Bartter syndrome
Bartter syndrome is correct because a defect in the sodium-potassium-2-chloride cotransporter of the thick ascending limb mimics chronic loop diuretic use, producing hypokalemic metabolic alkalosis with salt wasting, a high urine chloride, and normal-to-low blood pressure. Gitelman syndrome affects the distal thiazide-sensitive transporter, Liddle syndrome causes hypertension with low aldosterone, and distal renal tubular acidosis produces acidosis rather than alkalosis.
- A 55-year-old woman in septic shock has an arterial pH of 7.31, bicarbonate of 14 mmol/L, sodium 138, and chloride 104, giving an anion gap of 20. Her lactate is 6 mmol/L. Which acid-base process is the primary contributor?
- Normal anion gap metabolic acidosis
- Chloride-responsive metabolic alkalosis
- Respiratory alkalosis
- Lactic (high anion gap) metabolic acidosis
Correct answer: Lactic (high anion gap) metabolic acidosis
Lactic high anion gap metabolic acidosis is correct because tissue hypoperfusion in shock generates lactate, which is an unmeasured anion that widens the gap to 20 and lowers the bicarbonate, and the elevated lactate level confirms the source. A normal gap acidosis would keep the gap near 12, respiratory alkalosis would not lower the bicarbonate this way, and metabolic alkalosis raises rather than lowers the bicarbonate.
- A 48-year-old man is hospitalized and develops a rising creatinine, a maculopapular rash, low-grade fever, and peripheral eosinophilia one week after starting a proton pump inhibitor. Urinalysis shows white cells and white cell casts without bacteria. Which cause of acute kidney injury is most likely?
- Acute interstitial nephritis
- Acute tubular necrosis
- Prerenal azotemia
- Postrenal obstruction
Correct answer: Acute interstitial nephritis
Acute interstitial nephritis is correct because a recently introduced drug producing the combination of acute kidney injury, rash, fever, eosinophilia, and sterile pyuria with white cell casts is the classic allergic interstitial reaction, and proton pump inhibitors are well-recognized triggers. Tubular necrosis shows granular casts without allergic features, prerenal disease has bland urine, and obstruction is identified on imaging.
- A 70-year-old man with new oliguric acute kidney injury has a fractional excretion of sodium of 0.5 percent, a urine osmolality of 620 mOsm/kg, and a blood urea nitrogen to creatinine ratio of 25 to 1, with bland urinary sediment. Which category of acute kidney injury do these indices most strongly support?
- Intrinsic acute tubular necrosis
- Prerenal azotemia
- Acute interstitial nephritis
- Glomerulonephritis
Correct answer: Prerenal azotemia
Prerenal azotemia is correct because a fractional excretion of sodium below 1 percent, concentrated urine well above plasma osmolality, an elevated urea-to-creatinine ratio, and bland sediment all indicate intact tubules avidly reabsorbing salt and water in response to renal hypoperfusion. Acute tubular necrosis shows a fractional excretion above 2 percent with isosthenuric urine, interstitial nephritis shows pyuria, and glomerulonephritis shows red cell casts.
- A 68-year-old man develops acute kidney injury several days after cardiac catheterization, with livedo reticularis on the legs, transient eosinophilia, and a low complement level. Urinalysis is relatively bland. Which cause of acute kidney injury is most consistent with this presentation?
- Contrast-induced nephropathy
- Rhabdomyolysis
- Atheroembolic (cholesterol embolization) disease
- Minimal change disease
Correct answer: Atheroembolic (cholesterol embolization) disease
Atheroembolic disease is correct because dislodged cholesterol crystals after an arterial procedure embolize to the kidneys and skin, producing a subacute, often stepwise kidney injury with livedo reticularis, eosinophilia, and hypocomplementemia. Contrast nephropathy peaks within a few days and resolves without skin findings, rhabdomyolysis shows a high creatine kinase and pigmenturia, and minimal change disease causes nephrotic-range proteinuria.
- A 58-year-old woman with metastatic cancer develops oliguric acute kidney injury, and renal ultrasound shows bilateral hydronephrosis. Her bladder is not distended. Which is the most appropriate next step in management?
- Start a loop diuretic infusion
- Restrict fluids and observe
- Begin empiric corticosteroids
- Relieve the obstruction with ureteral stents or percutaneous nephrostomy
Correct answer: Relieve the obstruction with ureteral stents or percutaneous nephrostomy
Relieving the obstruction with ureteral stents or nephrostomy is correct because bilateral hydronephrosis with a non-distended bladder indicates ureteral obstruction above the bladder, and restoring urine drainage is required to reverse the postrenal acute kidney injury. Diuretics do not bypass a mechanical blockage, corticosteroids do not treat obstruction, and observation risks permanent loss of renal function.
- A 62-year-old woman with chronic kidney disease at an estimated glomerular filtration rate of 28 mL/min/1.73m2 is fatigued and pale, with a hemoglobin of 9 g/dL, a low transferrin saturation, and low ferritin. Which is the most appropriate first step before considering an erythropoiesis-stimulating agent?
- Begin a blood transfusion
- Repletion of iron stores
- Start an erythropoiesis-stimulating agent immediately
- Add a phosphate binder
Correct answer: Repletion of iron stores
Repletion of iron stores is correct because anemia of chronic kidney disease requires adequate iron before erythropoiesis-stimulating agents will work, and the low transferrin saturation and low ferritin here indicate true iron deficiency that must be corrected first. Transfusion is reserved for severe or symptomatic anemia, starting an erythropoiesis agent without iron is ineffective, and phosphate binders do not treat anemia.
- A 60-year-old man with chronic kidney disease and a stable estimated glomerular filtration rate of 35 mL/min/1.73m2 has a blood pressure of 150/90 mmHg and a urine albumin-to-creatinine ratio of 600 mg/g. Which antihypertensive is the most appropriate first choice to slow progression?
- An angiotensin-converting enzyme inhibitor or angiotensin receptor blocker
- A dihydropyridine calcium channel blocker
- A peripheral alpha-1 blocker
- Hydralazine
Correct answer: An angiotensin-converting enzyme inhibitor or angiotensin receptor blocker
An angiotensin-converting enzyme inhibitor or angiotensin receptor blocker is correct because in chronic kidney disease with significant albuminuria these agents lower intraglomerular pressure and reduce proteinuria, slowing progression beyond their blood pressure effect. Calcium channel blockers, alpha blockers, and hydralazine lower pressure but lack the specific antiproteinuric, renoprotective benefit needed here.
- A 55-year-old woman with chronic kidney disease at an estimated glomerular filtration rate of 25 mL/min/1.73m2 has a venous bicarbonate of 16 mmol/L on repeated testing, with no acute illness. Which intervention is recommended to address this finding and help slow kidney disease progression?
- A proton pump inhibitor
- A loop diuretic
- Increased dietary protein
- Oral sodium bicarbonate supplementation
Correct answer: Oral sodium bicarbonate supplementation
Oral sodium bicarbonate supplementation is correct because chronic metabolic acidosis is common in advanced kidney disease, and correcting a persistently low bicarbonate toward the normal range can slow the decline in renal function and reduce muscle and bone catabolism. A loop diuretic does not raise bicarbonate, higher protein intake increases the acid load, and a proton pump inhibitor does not treat metabolic acidosis.
- A 50-year-old man with type 2 diabetes, chronic kidney disease, and persistent albuminuria is already taking a maximally dosed angiotensin receptor blocker and a sodium-glucose cotransporter 2 inhibitor, yet albuminuria remains elevated and potassium is normal. Which additional agent has been shown to further reduce kidney and cardiovascular events in this diabetic kidney disease setting?
- A nondihydropyridine calcium channel blocker
- A nonsteroidal mineralocorticoid receptor antagonist such as finerenone
- A thiazide diuretic
- An alpha-glucosidase inhibitor
Correct answer: A nonsteroidal mineralocorticoid receptor antagonist such as finerenone
A nonsteroidal mineralocorticoid receptor antagonist such as finerenone is correct because in diabetic kidney disease with residual albuminuria on renin-angiotensin blockade it reduces progression and cardiovascular events while being added when potassium permits. A nondihydropyridine calcium channel blocker, a thiazide, and an alpha-glucosidase inhibitor do not provide this proven additional renoprotection.
- A 45-year-old man with diabetes and chronic kidney disease is found to have an estimated glomerular filtration rate of 58 mL/min/1.73m2 and a urine albumin-to-creatinine ratio of 250 mg/g, both confirmed and persistent over three months. According to current staging that combines filtration and albuminuria, how should his disease be classified?
- He does not have chronic kidney disease because filtration is above 60
- Acute kidney injury
- Chronic kidney disease defined by persistent moderately increased albuminuria despite filtration above 60
- End-stage kidney disease
Correct answer: Chronic kidney disease defined by persistent moderately increased albuminuria despite filtration above 60
Chronic kidney disease defined by persistent albuminuria is correct because the diagnosis requires either a reduced filtration rate or a marker of kidney damage such as albuminuria present for at least three months, so sustained moderately increased albuminuria qualifies even when filtration exceeds 60. Calling it normal ignores the albuminuria marker, this is chronic not acute given the three-month course, and end-stage disease requires far lower filtration or dialysis.
- A 26-year-old man with no diabetes develops sudden anasarca, a serum albumin of 2.0 g/dL, heavy proteinuria, and normal renal function. A biopsy shows normal glomeruli on light microscopy with diffuse foot process effacement on electron microscopy. Which is the most appropriate initial treatment?
- High-dose corticosteroids
- Plasma exchange
- A calcineurin inhibitor as first-line
- Rituximab as first-line
Correct answer: High-dose corticosteroids
High-dose corticosteroids are correct because the biopsy showing normal light microscopy with foot process effacement defines minimal change disease, which is highly steroid-responsive and treated first with corticosteroids in adults. Plasma exchange has no role here, and calcineurin inhibitors or rituximab are reserved for steroid-dependent, frequently relapsing, or steroid-resistant cases rather than initial therapy.
- A 40-year-old Black man with poorly controlled hypertension and obesity develops nephrotic-range proteinuria, and a renal biopsy shows segmental scarring affecting only portions of some glomeruli. Which diagnosis does this pattern represent?
- Membranoproliferative glomerulonephritis
- Membranous nephropathy
- Minimal change disease
- Focal segmental glomerulosclerosis
Correct answer: Focal segmental glomerulosclerosis
Focal segmental glomerulosclerosis is correct because scarring that involves only segments of some but not all glomeruli is the defining histologic pattern, and it is a leading cause of nephrotic syndrome that is often associated with hypertension and obesity. Membranoproliferative disease shows a different proliferative pattern, minimal change disease has normal light microscopy, and membranous nephropathy shows diffuse basement membrane thickening with subepithelial deposits.
- A 58-year-old man with newly diagnosed nephrotic syndrome and a serum albumin of 1.8 g/dL suddenly develops left flank pain, gross hematuria, and a rising creatinine. Which complication of the nephrotic state should be suspected first?
- Acute interstitial nephritis
- Renal vein thrombosis
- Nephrolithiasis
- Renal artery stenosis
Correct answer: Renal vein thrombosis
Renal vein thrombosis is correct because the nephrotic state, especially with severe hypoalbuminemia, produces a hypercoagulable condition from urinary loss of anticoagulant proteins, and acute flank pain with hematuria and worsening function is the classic presentation of this thrombotic complication. Interstitial nephritis is drug-related with sterile pyuria, stones cause colicky pain without the hypercoagulable link, and renal artery stenosis presents with resistant hypertension rather than acute flank pain.
- A 30-year-old man develops gross hematuria one to two days after an upper respiratory infection, with mild proteinuria and a normal complement level. Biopsy shows mesangial immunoglobulin A deposits. Which diagnosis is most consistent?
- Post-streptococcal glomerulonephritis
- Anti-glomerular basement membrane disease
- IgA nephropathy
- Membranous nephropathy
Correct answer: IgA nephropathy
IgA nephropathy is correct because gross hematuria appearing within a day or two of a mucosal infection, normal complement levels, and mesangial immunoglobulin A deposition on biopsy are the hallmark features of this most common primary glomerulonephritis. Post-streptococcal disease occurs one to several weeks after infection with low complement, anti-glomerular basement membrane disease shows linear staining and often lung involvement, and membranous nephropathy is a nephrotic rather than nephritic process.
- A 22-year-old woman develops periorbital edema, hypertension, tea-colored urine, and a rising creatinine about two weeks after a sore throat. Laboratory testing shows a low C3 complement and elevated antistreptolysin O titers, and urinalysis reveals red cell casts. Which diagnosis is most likely?
- Post-infectious (post-streptococcal) glomerulonephritis
- IgA nephropathy
- Thin basement membrane disease
- Diabetic nephropathy
Correct answer: Post-infectious (post-streptococcal) glomerulonephritis
Post-infectious glomerulonephritis is correct because a nephritic picture of edema, hypertension, hematuria with red cell casts, and a rising creatinine appearing one to several weeks after a streptococcal throat infection, accompanied by low C3 and elevated antistreptolysin O titers, is the classic presentation. IgA nephropathy occurs within days and keeps complement normal, thin basement membrane disease causes benign isolated hematuria, and diabetic nephropathy is a chronic nephrotic process.
- A 68-year-old man with chronic kidney disease has an estimated glomerular filtration rate of 8 mL/min/1.73m2 and presents with pericardial friction rub, nausea, asterixis, and a metallic taste, without volume overload responding to medication. Which is the most appropriate indication-based next step?
- Add a second oral phosphate binder
- Start an erythropoiesis-stimulating agent
- Increase dietary protein
- Initiate dialysis
Correct answer: Initiate dialysis
Initiating dialysis is correct because uremic symptoms such as pericarditis, encephalopathy with asterixis, and intractable nausea are recognized clinical indications to start renal replacement therapy regardless of a specific filtration number. A phosphate binder does not treat uremia, more dietary protein worsens the uremic load, and an erythropoiesis-stimulating agent addresses anemia but not these acute uremic manifestations.
- A 70-year-old man reports a weak urinary stream, hesitancy, nocturia, and incomplete emptying for the past year. Examination shows a smoothly enlarged, nontender prostate, and his prostate-specific antigen is only mildly elevated with a normal post-void residual. Which is the most appropriate first-line medical therapy to relieve his symptoms?
- A 5-alpha-reductase inhibitor used alone for immediate relief
- An anticholinergic agent
- An alpha-1 adrenergic blocker
- An indwelling urethral catheter
Correct answer: An alpha-1 adrenergic blocker
An alpha-1 adrenergic blocker is correct because relaxing prostatic and bladder neck smooth muscle provides rapid symptomatic relief of bladder outlet obstruction from benign prostatic hyperplasia, which the smoothly enlarged gland and obstructive symptoms indicate. A 5-alpha-reductase inhibitor shrinks the gland only over months and is not for immediate relief, anticholinergics can worsen retention, and a catheter is not first-line management.
- A 35-year-old man has recurrent calcium oxalate kidney stones, and a 24-hour urine collection shows hypercalciuria with normal serum calcium. Beyond increasing fluid intake, which medication is most appropriate to reduce his urinary calcium and prevent further stones?
- A loop diuretic
- A thiazide diuretic
- Calcium carbonate supplementation
- Acetazolamide
Correct answer: A thiazide diuretic
A thiazide diuretic is correct because thiazides enhance distal tubular calcium reabsorption, lowering urinary calcium excretion and reducing recurrent calcium stone formation in patients with hypercalciuria. Loop diuretics increase urinary calcium and can worsen stones, extra calcium supplementation can raise urinary calcium, and acetazolamide alkalinizes the urine and may promote calcium phosphate stones.
- A 26-year-old woman with recurrent kidney stones is found to have stones composed of cystine and a characteristic hexagonal crystal on urinalysis. Which underlying mechanism explains her stone disease?
- An inherited defect in renal tubular reabsorption of cystine
- Excess dietary purine intake
- Chronic urinary tract infection with urease-producing bacteria
- Primary hyperparathyroidism
Correct answer: An inherited defect in renal tubular reabsorption of cystine
An inherited defect in renal tubular reabsorption of cystine is correct because cystinuria is an autosomal disorder of dibasic amino acid transport that causes poorly soluble cystine to precipitate into stones, producing the characteristic hexagonal crystals. Excess purines cause uric acid stones, urease-producing infection causes struvite stones, and primary hyperparathyroidism causes calcium stones, none of which form cystine crystals.
- A 72-year-old man with metastatic prostate cancer to the bone is started on therapy and asks how most prostate cancers are treated when they have spread beyond the gland. Which is the cornerstone of treatment for metastatic prostate cancer?
- Renal transplantation
- Broad-spectrum antibiotics
- A thiazide diuretic
- Androgen deprivation therapy
Correct answer: Androgen deprivation therapy
Androgen deprivation therapy is correct because prostate adenocarcinoma growth is driven by androgens, so lowering testosterone through medical or surgical castration is the foundation of treatment for metastatic disease, often combined with additional agents. Antibiotics treat infection rather than cancer, a thiazide addresses calcium handling, and transplantation has no role in treating prostate cancer.
- A 64-year-old man develops acute oliguric kidney injury after major surgery complicated by prolonged hypotension. Urinalysis shows muddy brown granular casts and renal tubular epithelial cells, the fractional excretion of sodium is 3 percent, and the urine is isosthenuric. Which cause of acute kidney injury is most likely?
- Prerenal azotemia
- Acute tubular necrosis
- Postrenal obstruction
- Minimal change disease
Correct answer: Acute tubular necrosis
Acute tubular necrosis is correct because a sustained ischemic insult from prolonged hypotension injures the tubules, producing the characteristic muddy brown granular casts, renal tubular epithelial cells, a fractional excretion of sodium above 2 percent, and isosthenuric urine that reflect lost concentrating and sodium-reabsorbing function. Prerenal azotemia shows a fractional excretion below 1 percent with concentrated urine, obstruction is seen on imaging, and minimal change disease causes nephrotic-range proteinuria rather than this picture.
