Viral Infections USMLE Step 1 Practice Question
A 7-year-old boy presents with 3 days of high fever (39.8°C), cough, and rhinorrhea. He now has a characteristic maculopapular rash beginning on the face and spreading downward. Physical examination reveals Koplik spots on his buccal mucosa and conjunctival injection. Vital signs show HR 112/min, RR 24/min, and SpO2 98% on room air. Chest X-ray demonstrates no pneumonic infiltrates. He has not received MMR vaccination. Which of the following is the most likely diagnosis?
Answer choices
- AVaricella
- BMeaslesCorrect answer
- CRoseola infantum
- DErythema infectiosum
- ERubella
- FScarlet fever
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