These 11 quick USMLE review questions test high-yield facts that show up again and again on the exam: candidiasis diagnosis, clinical trial phases, Turner syndrome treatment, obstructive jaundice, asthma attacks, pancreatitis, neonatal eye prophylaxis, neonatal seizures, congenital rubella, COPD exacerbation and hypothyroidism. Each question includes the correct answer.
Written by Dr. Ray Makar, MD, author of the Repeated USMLE Questions eBook series.
How to use this page: read the question, pick your answer, then tap Show Answer and Explanation.
Questions
Question 1. Diagnosis of candidiasis is based on which one of the following laboratory tests?
A- Culture from the affected area
B- Potassium hydroxide (KOH) wet mount
C- Skin biopsy
D- Wright’s stain test
B- Potassium hydroxide (KOH) wet mount- A KOH wet mount is a rapid and commonly used test for diagnosing candidiasis. It involves mixing a sample (skin scraping, vaginal swab, or oral swab) with potassium hydroxide (KOH) to dissolve background debris, allowing fungal elements (such as Candida hyphae or budding yeast) to be seen under a microscope.
While culture from the nails is useful for diagnosing fungal infections like onychomycosis, Candida infections are often identified more quickly with KOH prep.
The correct answer is B
Question 2. Which one of the following clinical trials primarily evaluates drug safety?
A- Phase I
B- Phase II
C- Phase III
D- Phase IV
A- Phase I- This phase primarily evaluates drug safety. It includes 100–300 patients with the disease. Phase II evaluates efficacy and continues to evaluate safety. Phase III confirms efficacy, monitors side effects, compares with existing treatments. Phase IV is the post-marketing surveillance to detect long-term adverse and rare side effects after the drug is approved.
The correct answer is A
Question 3. A female infant is diagnosed with Turner syndrome. Which one of the following long-term hormone replacement therapies should be started when she reaches puberty?
A- Estrogen only
B- Estrogen and progestin
C- Progestin only
D- Prolactin and progestin
B- Estrogen and progestin- Turner syndrome (45,X) is associated with gonadal dysgenesis, leading to estrogen deficiency and lack of spontaneous puberty. Hormone replacement therapy (HRT) is used to induce secondary sexual characteristics, promote normal growth and bone health, initiate and regulate menstrual cycles, and prevent osteoporosis. Estrogen is started around age 11–12 to begin pubertal development. Progestin is added after 1–2 years of estrogen therapy or once breakthrough bleeding occurs, to prevent endometrial hyperplasia due to unopposed estrogen.
The correct answer is B
Question 4. Which of the following laboratory values is most commonly elevated in cases of obstructive jaundice?
A- ALT
B- AST
C- Alkaline phosphatase
D- Unconjugated bilirubin
C- Alkaline phosphatase- In obstructive jaundice, alkaline phosphatase is usually elevated more than transaminases. It reflects bile duct obstruction or cholestasis.
The correct answer is C
Question 5. Which of the following is the first-line treatment for a case of acute asthma exacerbation?
D- Short-acting beta 2 agonists- SABAs such as albuterol are the first line of treatment in acute asthma attacks because they work quickly to relax bronchial smooth muscle and open the airways.
The correct answer is D
Question 6. Which of the following is the most sensitive test for diagnosing a case of acute pancreatitis?
A- ALT
B- Amylase
C- CT of abdomen
D- Lipase
D- Lipase-is more specific and remains elevated longer than amylase in acute pancreatitis.
The correct answer is D
Question 7. Routine prophylactic eye antimicrobial therapy is administered to all newborns to prevent blindness caused by which of the following organisms?
D- Neisseria gonorrhea- Erythromycin ointment is usually applied to all newborns shortly after birth to prevent ophthalmia neonatorum caused by Neisseria gonorrhea. This infection can lead to rapidly progressing conjunctivitis and permanent blindness if untreated.
The correct answer is D
Question 8. Which of the following is the most common cause of clonic seizures in the first 24 hours of a newborn?
D- Hypoxic ischemic encephalopathy- Clonic seizures in the first 24 hours of a newborn are most commonly caused by hypoxic ischemic encephalopathy. This condition results from perinatal asphyxia, leading to poor oxygen and blood flow to the brain. It is commonly presented with seizures on the first day of life. Hypoglycemia and hypocalcemia are common metabolic causes but typically present after the first day. Birth trauma and intracranial hemorrhage can cause seizures, but less common compared to HIE.
The correct answer is D
Question 9. Which of the following neonatal findings suggests congenital rubella syndrome?
A- Cataracts- Congenital rubella syndrome (CRS) classically presents with a triad:
Sensorineural deafness
Cataracts (or other eye abnormalities like retinopathy)
Congenital heart disease (especially patent ductus arteriosus)
Other associated findings may include:
“Blueberry muffin” rash (due to dermal extramedullary hematopoiesis)
Hepatosplenomegaly
Thrombocytopenia
Growth restriction
The correct answer is A
Question 10. A 72-year-old man with chronic obstructive pulmonary disease (COPD) presents with worsening dyspnea and cough producing purulent sputum. His O₂ saturation is 85% on room air. Which of the following is the best initial treatment?
A- Oral prednisone and broad-spectrum antibiotics
B- Oxygen to maintain SpO₂ between 88% and 92%
C- Immediate intubation and mechanical ventilation
D- Chest physiotherapy and mucolytic agents only
B- Oxygen to maintain SpO₂ between 88% and 92%- In COPD exacerbations, oxygen should be administered to maintain moderate oxygenation and prevent worsening hypercapnia from loss of hypoxic drive. Further treatment includes bronchodilators, systemic corticosteroids, and antibiotics if bacterial infection is suspected.
The correct answer is B
Question 11. A 32-year-old woman presents with 2 weeks of fatigue, weight gain, constipation, and cold intolerance. Physical exam reveals coarse hair and dry skin. Labs are TSH 12 mIU/L (↑), free T₄ low. Which of the following is the most likely diagnosis?
B- Hashimoto thyroiditis- The most common cause of hypothyroidism in developed countries is autoimmune thyroiditis (Hashimoto’s disease), characterized by anti-thyroid peroxidase antibodies infiltration of the thyroid.
The correct answer is B