USMLE STEP 2 CK – PRACTICE QUESTIONS AND CORRECT ANSWERS (VERIFIED ANSWERS) PLUS RATIONALES 2026 Q&A |
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*Core Domains:*
*- Internal Medicine*
*- Surgery*
*- Pediatrics*
*- Obstetrics and Gynecology*
*- Psychiatry*
*- Family Medicine*
*- Emergency Medicine*
*- Epidemiology and Biostatistics*
*- Medical Ethics and Legal Compliance*
*Introduction:*
*This assessment is designed to evaluate clinical knowledge and the ability to apply foundational medical concepts essential for deliver
SECTION ONE
Question 1
A 45-year-old male presents with a 2-day history of acute, severe pain and swelling in his left first metatarsophalangeal joint. He reports no
trauma. Medical history includes hypertension, managed with hydrochlorothiazide. On examination, the joint is erythematous, warm, and
exquisitely tender. Synovial fluid analysis reveals negatively birefringent, needle-shaped crystals. What is the most appropriate initial
management for this patient's acute condition?
A. Allopurinol
B. Indomethacin
C. Colchicine and Allopurinol
D. Febuxostat
🟢 B. Indomethacin
🔴 RATIONALE: The clinical presentation and synovial fluid findings are diagnostic of acute gouty arthritis. First-line therapy for acute gout
flares includes nonsteroidal anti-inflammatory drugs (NSAIDs) such as indomethacin, systemic or intra-articular corticosteroids, or colchicine.
,Urate-lowering therapies like allopurinol and febuxostat should not be initiated during an acute flare, as rapid shifts in serum uric acid levels
can exacerbate or prolong the acute inflammation.
Question 2
A 62-year-old female with a history of chronic obstructive pulmonary disease (COPD) presents to the emergency department with worsening
shortness of breath and a productive cough over the past 3 days. Arterial blood gas on room air shows pH 7.31, PaCO2 55 mm Hg, and
PaO2 58 mm Hg. In addition to oxygen therapy and bronchodilators, which of the following interventions has been shown to reduce mortality
in an acute exacerbation of COPD?
A. Inhaled fluticasone
B. Systemic corticosteroids
C. Prophylactic azithromycin
D. Noninvasive positive pressure ventilation
🟢 D. Noninvasive positive pressure ventilation
🔴 RATIONALE: For patients with acute exacerbations of COPD causing respiratory acidosis (pH less than 7.35) and hypercapnia,
noninvasive positive pressure ventilation (NIPPV) significantly decreases the need for endotracheal intubation, shortens hospital stays, and
reduces mortality. Systemic corticosteroids and antibiotics are standard components of care that improve clinical outcomes, but NIPPV
provides immediate physical support to reverse respiratory failure.
Question 3
A 28-year-old primigravida at 34 weeks gestation presents to the labor and delivery unit with a headache and visual spots for 4 hours. Her
blood pressure is 165/110 mm Hg on two readings taken 15 minutes apart. Urinalysis shows 3+ protein. Laboratory evaluation reveals a
platelet count of 85,000/mm^3, aspartate aminotransferase (AST) 120 U/L, and creatinine 1.4 mg/dL. Which of the following is the most
appropriate next step in management?
A. Immediate cesarean delivery
B. Initiate magnesium sulfate and plan for delivery
C. Administer oral labetalol and discharge home with close follow-up
D. Administer betamethasone and delay delivery for 48 hours
🟢 B. Initiate magnesium sulfate and plan for delivery
🔴 RATIONALE: This patient meets the diagnostic criteria for preeclampsia with severe features based on her blood pressure, proteinuria,
thrombocytopenia, elevated liver enzymes, and renal insufficiency. At 34 weeks or greater gestation, immediate stabilization and delivery are
indicated to prevent maternal and fetal complications. Magnesium sulfate must be initiated immediately for seizure prophylaxis, and
antihypertensives should be given to lower blood pressure, followed by induction of labor or cesarean section based on obstetric indications.
Question 4
A 4-year-old boy is brought to the clinic due to a 5-day history of high fever, conjunctival injection without exudate, a polymorphous rash on
his trunk, and swelling of his hands and feet. On examination, he has a prominent "strawberry tongue" and unilateral cervical
lymphadenopathy measuring 1.8 cm. What is the most critical long-term complication associated with this condition if left untreated?
A. Acute rheumatic fever
B. Splenic rupture
,C. Coronary artery aneurysms
D. Chronic glomerulonephritis
🟢 C. Coronary artery aneurysms
🔴 RATIONALE: The clinical features describe Kawasaki disease, an acute febrile vasculitis of childhood. The most significant complication
of untreated Kawasaki disease is the development of coronary artery aneurysms, which occurs in up to 25% of untreated patients. Timely
administration of intravenous immunoglobulin (IVIG) and high-dose aspirin within the first 10 days of fever onset markedly reduces this risk to
less than 5%.
Question 5
A 72-year-old male is brought to the emergency department by his family because of progressive confusion, lethargy, and general weakness
over the past week. His past medical history is significant for small cell lung cancer. Laboratory evaluation reveals a serum sodium level of
118 mEq/L, serum osmolality of 250 mOsm/kg, and urine osmolality of 450 mOsm/kg. He is euvolemic on physical examination. What is the
most appropriate initial step in managing this patient's hyponatremia?
A. Intravenous bolus of 3% hypertonic saline
B. Fluid restriction
C. Intravenous normal saline infusion
D. Oral demeclocycline
🟢 B. Fluid restriction
🔴 RATIONALE: The patient has hypotonic, euvolemic hyponatremia with inappropriately concentrated urine, which is classic for the
Syndrome of Inappropriate Antidiuretic Hormone (SIADH), frequently associated with small cell lung cancer. For patients with mild-to-
moderate or chronic symptoms of SIADH, the primary therapeutic intervention is strict fluid restriction. Hypertonic saline is reserved for
patients presenting with severe, life-threatening neurological symptoms such as seizures or coma.
Question 6
A 35-year-old female presents to the clinic complaining of double vision, particularly in the evening, and difficulty chewing her food towards
the end of meals. She notes that her symptoms improve significantly after resting. Physical examination reveals bilateral ptosis that worsens
during prolonged upward gaze. No muscular atrophy is noted. Which of the following is the underlying pathophysiology of this patient's
condition?
A. Destruction of voltage-gated calcium channels
B. Autoimmune destruction of myelin in the central nervous system
C. Autoantibodies against postsynaptic acetylcholine receptors
D. Toxin-mediated inhibition of acetylcholine release
🟢 C. Autoantibodies against postsynaptic acetylcholine receptors
🔴 RATIONALE: The patient's clinical presentation is highly characteristic of myasthenia gravis, an autoimmune disorder characterized by
fluctuating skeletal muscle weakness that worsens with activity and improves with rest. The condition is caused by autoantibodies directed
against the postsynaptic nicotinic acetylcholine receptors at the neuromuscular junction, leading to a reduction in available receptors and
impaired neuromuscular transmission.
Question 7
, A 54-year-old man with a history of alcohol use disorder is brought to the emergency department after being found unresponsive on the
street. On examination, he is stuporous, cachectic, and has a respiratory rate of 8 breaths per minute. His breath smells of alcohol. Blood
glucose is 42 mg/dL. In addition to managing his airway and administering intravenous dextrose, which of the following medications must be
administered immediately to prevent neurological damage?
A. Thiamine
B. Naloxone
C. Flumazenil
D. Pyridoxine
🟢 A. Thiamine
🔴 RATIONALE: In patients with chronic alcoholism or malnutrition presenting with altered mental status and hypoglycemia, intravenous
thiamine must be administered prior to or concurrently with intravenous dextrose. Giving dextrose without thiamine can precipitate or worsen
Wernicke encephalopathy (characterized by encephalopathy, oculomotor dysfunction, and ataxia) due to rapid consumption of remaining
thiamine stores during glucose metabolism.
Question 8
A 19-year-old male college student is brought to the emergency department with a 12-hour history of severe headache, high fever, and
photophobia. On examination, his temperature is 39.2°C (102.6°F), blood pressure is 100/60 mm Hg, and heart rate is 115 beats per minute.
He has neck stiffness and a petechial rash on his lower extremities. Lumbar puncture is performed. While awaiting cerebrospinal fluid
analysis results, which empiric antibiotic regimen should be initiated immediately?
A. Ceftriaxone and Vancomycin
B. Ampicillin and Gentamicin
C. Penicillin G alone
D. Ceftriaxone, Vancomycin, and Ampicillin
🟢 A. Ceftriaxone and Vancomycin
🔴 RATIONALE: The presentation of fever, headache, altered mental status, meningismus, and a petechial rash strongly suggests acute
bacterial meningitis, most likely due to Neisseria meningitidis or Streptococcus pneumoniae. Empiric therapy for adults under 50 years of age
consists of a third-generation cephalosporin (e.g., ceftriaxone) to cover major pathogens plus vancomycin to cover penicillin-resistant
pneumococci. Ampicillin is added only for patients over 50 or those with altered cell-mediated immunity to cover Listeria monocytogenes.
Question 9
A 68-year-old male presents to his primary care physician for a routine wellness exam. He has a 40 pack-year smoking history but quit 5
years ago. He has no current symptoms. According to the United States Preventive Services Task Force (USPSTF) guidelines, which
screening intervention is specifically recommended for this patient based on his age and smoking history?
A. Screening colonoscopy
B. Low-dose computed tomography of the chest
C. Abdominal aortic ultrasound
D. Digital rectal examination and PSA testing
🟢 C. Abdominal aortic ultrasound
INSTANT DOWNLOAD PDF
*Core Domains:*
*- Internal Medicine*
*- Surgery*
*- Pediatrics*
*- Obstetrics and Gynecology*
*- Psychiatry*
*- Family Medicine*
*- Emergency Medicine*
*- Epidemiology and Biostatistics*
*- Medical Ethics and Legal Compliance*
*Introduction:*
*This assessment is designed to evaluate clinical knowledge and the ability to apply foundational medical concepts essential for deliver
SECTION ONE
Question 1
A 45-year-old male presents with a 2-day history of acute, severe pain and swelling in his left first metatarsophalangeal joint. He reports no
trauma. Medical history includes hypertension, managed with hydrochlorothiazide. On examination, the joint is erythematous, warm, and
exquisitely tender. Synovial fluid analysis reveals negatively birefringent, needle-shaped crystals. What is the most appropriate initial
management for this patient's acute condition?
A. Allopurinol
B. Indomethacin
C. Colchicine and Allopurinol
D. Febuxostat
🟢 B. Indomethacin
🔴 RATIONALE: The clinical presentation and synovial fluid findings are diagnostic of acute gouty arthritis. First-line therapy for acute gout
flares includes nonsteroidal anti-inflammatory drugs (NSAIDs) such as indomethacin, systemic or intra-articular corticosteroids, or colchicine.
,Urate-lowering therapies like allopurinol and febuxostat should not be initiated during an acute flare, as rapid shifts in serum uric acid levels
can exacerbate or prolong the acute inflammation.
Question 2
A 62-year-old female with a history of chronic obstructive pulmonary disease (COPD) presents to the emergency department with worsening
shortness of breath and a productive cough over the past 3 days. Arterial blood gas on room air shows pH 7.31, PaCO2 55 mm Hg, and
PaO2 58 mm Hg. In addition to oxygen therapy and bronchodilators, which of the following interventions has been shown to reduce mortality
in an acute exacerbation of COPD?
A. Inhaled fluticasone
B. Systemic corticosteroids
C. Prophylactic azithromycin
D. Noninvasive positive pressure ventilation
🟢 D. Noninvasive positive pressure ventilation
🔴 RATIONALE: For patients with acute exacerbations of COPD causing respiratory acidosis (pH less than 7.35) and hypercapnia,
noninvasive positive pressure ventilation (NIPPV) significantly decreases the need for endotracheal intubation, shortens hospital stays, and
reduces mortality. Systemic corticosteroids and antibiotics are standard components of care that improve clinical outcomes, but NIPPV
provides immediate physical support to reverse respiratory failure.
Question 3
A 28-year-old primigravida at 34 weeks gestation presents to the labor and delivery unit with a headache and visual spots for 4 hours. Her
blood pressure is 165/110 mm Hg on two readings taken 15 minutes apart. Urinalysis shows 3+ protein. Laboratory evaluation reveals a
platelet count of 85,000/mm^3, aspartate aminotransferase (AST) 120 U/L, and creatinine 1.4 mg/dL. Which of the following is the most
appropriate next step in management?
A. Immediate cesarean delivery
B. Initiate magnesium sulfate and plan for delivery
C. Administer oral labetalol and discharge home with close follow-up
D. Administer betamethasone and delay delivery for 48 hours
🟢 B. Initiate magnesium sulfate and plan for delivery
🔴 RATIONALE: This patient meets the diagnostic criteria for preeclampsia with severe features based on her blood pressure, proteinuria,
thrombocytopenia, elevated liver enzymes, and renal insufficiency. At 34 weeks or greater gestation, immediate stabilization and delivery are
indicated to prevent maternal and fetal complications. Magnesium sulfate must be initiated immediately for seizure prophylaxis, and
antihypertensives should be given to lower blood pressure, followed by induction of labor or cesarean section based on obstetric indications.
Question 4
A 4-year-old boy is brought to the clinic due to a 5-day history of high fever, conjunctival injection without exudate, a polymorphous rash on
his trunk, and swelling of his hands and feet. On examination, he has a prominent "strawberry tongue" and unilateral cervical
lymphadenopathy measuring 1.8 cm. What is the most critical long-term complication associated with this condition if left untreated?
A. Acute rheumatic fever
B. Splenic rupture
,C. Coronary artery aneurysms
D. Chronic glomerulonephritis
🟢 C. Coronary artery aneurysms
🔴 RATIONALE: The clinical features describe Kawasaki disease, an acute febrile vasculitis of childhood. The most significant complication
of untreated Kawasaki disease is the development of coronary artery aneurysms, which occurs in up to 25% of untreated patients. Timely
administration of intravenous immunoglobulin (IVIG) and high-dose aspirin within the first 10 days of fever onset markedly reduces this risk to
less than 5%.
Question 5
A 72-year-old male is brought to the emergency department by his family because of progressive confusion, lethargy, and general weakness
over the past week. His past medical history is significant for small cell lung cancer. Laboratory evaluation reveals a serum sodium level of
118 mEq/L, serum osmolality of 250 mOsm/kg, and urine osmolality of 450 mOsm/kg. He is euvolemic on physical examination. What is the
most appropriate initial step in managing this patient's hyponatremia?
A. Intravenous bolus of 3% hypertonic saline
B. Fluid restriction
C. Intravenous normal saline infusion
D. Oral demeclocycline
🟢 B. Fluid restriction
🔴 RATIONALE: The patient has hypotonic, euvolemic hyponatremia with inappropriately concentrated urine, which is classic for the
Syndrome of Inappropriate Antidiuretic Hormone (SIADH), frequently associated with small cell lung cancer. For patients with mild-to-
moderate or chronic symptoms of SIADH, the primary therapeutic intervention is strict fluid restriction. Hypertonic saline is reserved for
patients presenting with severe, life-threatening neurological symptoms such as seizures or coma.
Question 6
A 35-year-old female presents to the clinic complaining of double vision, particularly in the evening, and difficulty chewing her food towards
the end of meals. She notes that her symptoms improve significantly after resting. Physical examination reveals bilateral ptosis that worsens
during prolonged upward gaze. No muscular atrophy is noted. Which of the following is the underlying pathophysiology of this patient's
condition?
A. Destruction of voltage-gated calcium channels
B. Autoimmune destruction of myelin in the central nervous system
C. Autoantibodies against postsynaptic acetylcholine receptors
D. Toxin-mediated inhibition of acetylcholine release
🟢 C. Autoantibodies against postsynaptic acetylcholine receptors
🔴 RATIONALE: The patient's clinical presentation is highly characteristic of myasthenia gravis, an autoimmune disorder characterized by
fluctuating skeletal muscle weakness that worsens with activity and improves with rest. The condition is caused by autoantibodies directed
against the postsynaptic nicotinic acetylcholine receptors at the neuromuscular junction, leading to a reduction in available receptors and
impaired neuromuscular transmission.
Question 7
, A 54-year-old man with a history of alcohol use disorder is brought to the emergency department after being found unresponsive on the
street. On examination, he is stuporous, cachectic, and has a respiratory rate of 8 breaths per minute. His breath smells of alcohol. Blood
glucose is 42 mg/dL. In addition to managing his airway and administering intravenous dextrose, which of the following medications must be
administered immediately to prevent neurological damage?
A. Thiamine
B. Naloxone
C. Flumazenil
D. Pyridoxine
🟢 A. Thiamine
🔴 RATIONALE: In patients with chronic alcoholism or malnutrition presenting with altered mental status and hypoglycemia, intravenous
thiamine must be administered prior to or concurrently with intravenous dextrose. Giving dextrose without thiamine can precipitate or worsen
Wernicke encephalopathy (characterized by encephalopathy, oculomotor dysfunction, and ataxia) due to rapid consumption of remaining
thiamine stores during glucose metabolism.
Question 8
A 19-year-old male college student is brought to the emergency department with a 12-hour history of severe headache, high fever, and
photophobia. On examination, his temperature is 39.2°C (102.6°F), blood pressure is 100/60 mm Hg, and heart rate is 115 beats per minute.
He has neck stiffness and a petechial rash on his lower extremities. Lumbar puncture is performed. While awaiting cerebrospinal fluid
analysis results, which empiric antibiotic regimen should be initiated immediately?
A. Ceftriaxone and Vancomycin
B. Ampicillin and Gentamicin
C. Penicillin G alone
D. Ceftriaxone, Vancomycin, and Ampicillin
🟢 A. Ceftriaxone and Vancomycin
🔴 RATIONALE: The presentation of fever, headache, altered mental status, meningismus, and a petechial rash strongly suggests acute
bacterial meningitis, most likely due to Neisseria meningitidis or Streptococcus pneumoniae. Empiric therapy for adults under 50 years of age
consists of a third-generation cephalosporin (e.g., ceftriaxone) to cover major pathogens plus vancomycin to cover penicillin-resistant
pneumococci. Ampicillin is added only for patients over 50 or those with altered cell-mediated immunity to cover Listeria monocytogenes.
Question 9
A 68-year-old male presents to his primary care physician for a routine wellness exam. He has a 40 pack-year smoking history but quit 5
years ago. He has no current symptoms. According to the United States Preventive Services Task Force (USPSTF) guidelines, which
screening intervention is specifically recommended for this patient based on his age and smoking history?
A. Screening colonoscopy
B. Low-dose computed tomography of the chest
C. Abdominal aortic ultrasound
D. Digital rectal examination and PSA testing
🟢 C. Abdominal aortic ultrasound
