USMLE Step 2 CK – 100-Question
Comprehensive Practice Examination
(With Answers & Rationales)
1. A 64-year-old man with COPD presents with worsening dyspnea and
wheezing. He has a productive cough and purulent sputum. Temp 38.1°C. Best
next step?
A. Oral prednisone only
B. Inhaled bronchodilator only
C. Oral antibiotics plus systemic steroids
D. Hospital admission only
E. Chest CT scan
Answer: C. Oral antibiotics plus systemic steroids
Rationale: COPD exacerbation with increased sputum purulence and fever
requires antibiotics in addition to steroids.
2. A 22-year-old woman with fatigue and heavy menses has Hb 8.7 g/dL, MCV
70 fL. Best initial test?
A. Bone marrow biopsy
B. Serum ferritin
C. TIBC
D. Hemoglobin electrophoresis
E. Reticulocyte index
,Answer: B. Serum ferritin
Rationale: Iron deficiency anemia is suspected; ferritin is the most accurate
initial test.
3. A 70-year-old man presents with crushing chest pain for 30 minutes. ECG
shows ST elevations in II, III, aVF. Next step?
A. Stress test
B. Chest X-ray
C. Cardiac enzymes
D. Immediate PCI
E. Nitroglycerin only
Answer: D. Immediate PCI
Rationale: STEMI requires emergent reperfusion therapy.
4. A 5-year-old boy has barking cough, hoarse voice, and inspiratory stridor.
Next step?
A. Chest X-ray
B. Dexamethasone
C. Intubation
D. Antibiotics
E. Racemic epinephrine only
Answer: B. Dexamethasone
Rationale: Mild–moderate croup is treated with corticosteroids; racemic
epinephrine is added only for severe stridor.
5. A 30-year-old man with polyuria and polydipsia has fasting glucose 135 mg/dL
and HbA1c 6.7%. Diagnosis?
,A. Impaired fasting glucose
B. Type 2 diabetes
C. Type 1 diabetes
D. Diabetes insipidus
E. RENAL glucosuria
Answer: B. Type 2 diabetes
Rationale: A1c ≥6.5% confirms diabetes.
6. An alcoholic man presents with confusion, ophthalmoplegia, and ataxia.
Treatment?
A. Glucose
B. IV fluids
C. Naloxone
D. Thiamine
E. Vitamin B12
Answer: D. Thiamine
Rationale: Wernicke encephalopathy is treated with thiamine before glucose.
7. A newborn has a continuous machine-like murmur. What defect?
A. Tetralogy of Fallot
B. ASD
C. VSD
D. PDA
E. Coarctation
Answer: D. PDA
Rationale: PDA classically presents with a continuous machinery murmur.
, 8. A woman has RUQ pain, fever, leukocytosis, and gallstones. Dx?
A. Cholangitis
B. Acute cholecystitis
C. Chronic cholecystitis
D. Choledocholithiasis
E. Pancreatitis
Answer: B. Acute cholecystitis
Rationale: RUQ pain + fever + gallstones suggests acute cholecystitis.
9. A 44-year-old man with HIV has CD4 count 150. Best prophylaxis?
A. Azithromycin
B. Fluconazole
C. TMP-SMX
D. Ganciclovir
E. Rifampin
Answer: C. TMP-SMX
Rationale: CD4 <200 requires Pneumocystis prophylaxis with TMP-SMX.
10. A patient with palpitations has an irregularly irregular rhythm. First test?
A. Cardiac enzymes
B. Chest X-ray
C. ECG
D. Echocardiogram
E. Holter monitor
Answer: C. ECG
Rationale: AFib diagnosis is confirmed by ECG.
Comprehensive Practice Examination
(With Answers & Rationales)
1. A 64-year-old man with COPD presents with worsening dyspnea and
wheezing. He has a productive cough and purulent sputum. Temp 38.1°C. Best
next step?
A. Oral prednisone only
B. Inhaled bronchodilator only
C. Oral antibiotics plus systemic steroids
D. Hospital admission only
E. Chest CT scan
Answer: C. Oral antibiotics plus systemic steroids
Rationale: COPD exacerbation with increased sputum purulence and fever
requires antibiotics in addition to steroids.
2. A 22-year-old woman with fatigue and heavy menses has Hb 8.7 g/dL, MCV
70 fL. Best initial test?
A. Bone marrow biopsy
B. Serum ferritin
C. TIBC
D. Hemoglobin electrophoresis
E. Reticulocyte index
,Answer: B. Serum ferritin
Rationale: Iron deficiency anemia is suspected; ferritin is the most accurate
initial test.
3. A 70-year-old man presents with crushing chest pain for 30 minutes. ECG
shows ST elevations in II, III, aVF. Next step?
A. Stress test
B. Chest X-ray
C. Cardiac enzymes
D. Immediate PCI
E. Nitroglycerin only
Answer: D. Immediate PCI
Rationale: STEMI requires emergent reperfusion therapy.
4. A 5-year-old boy has barking cough, hoarse voice, and inspiratory stridor.
Next step?
A. Chest X-ray
B. Dexamethasone
C. Intubation
D. Antibiotics
E. Racemic epinephrine only
Answer: B. Dexamethasone
Rationale: Mild–moderate croup is treated with corticosteroids; racemic
epinephrine is added only for severe stridor.
5. A 30-year-old man with polyuria and polydipsia has fasting glucose 135 mg/dL
and HbA1c 6.7%. Diagnosis?
,A. Impaired fasting glucose
B. Type 2 diabetes
C. Type 1 diabetes
D. Diabetes insipidus
E. RENAL glucosuria
Answer: B. Type 2 diabetes
Rationale: A1c ≥6.5% confirms diabetes.
6. An alcoholic man presents with confusion, ophthalmoplegia, and ataxia.
Treatment?
A. Glucose
B. IV fluids
C. Naloxone
D. Thiamine
E. Vitamin B12
Answer: D. Thiamine
Rationale: Wernicke encephalopathy is treated with thiamine before glucose.
7. A newborn has a continuous machine-like murmur. What defect?
A. Tetralogy of Fallot
B. ASD
C. VSD
D. PDA
E. Coarctation
Answer: D. PDA
Rationale: PDA classically presents with a continuous machinery murmur.
, 8. A woman has RUQ pain, fever, leukocytosis, and gallstones. Dx?
A. Cholangitis
B. Acute cholecystitis
C. Chronic cholecystitis
D. Choledocholithiasis
E. Pancreatitis
Answer: B. Acute cholecystitis
Rationale: RUQ pain + fever + gallstones suggests acute cholecystitis.
9. A 44-year-old man with HIV has CD4 count 150. Best prophylaxis?
A. Azithromycin
B. Fluconazole
C. TMP-SMX
D. Ganciclovir
E. Rifampin
Answer: C. TMP-SMX
Rationale: CD4 <200 requires Pneumocystis prophylaxis with TMP-SMX.
10. A patient with palpitations has an irregularly irregular rhythm. First test?
A. Cardiac enzymes
B. Chest X-ray
C. ECG
D. Echocardiogram
E. Holter monitor
Answer: C. ECG
Rationale: AFib diagnosis is confirmed by ECG.
