skip to main content

Physiologic jaundice — USMLE Step 3 MCQ

Instant feedback + full explanation. One question, done properly.

HardPediatrics (well-child, chronic management)Physiologic jaundiceUSMLE Step 3

A 10-day-old infant has vesicles, lethargy, CSF HSV PCR positivity, and normal renal function. Which regimen is appropriate?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: A — Acyclovir 20 mg/kg IV every 8 hours for 21 days

The best answer is “Acyclovir 20 mg/kg IV every 8 hours for 21 days”. CSF involvement is neonatal CNS HSV and requires the 21-day IV course. Neonatal HSV is treated with acyclovir 20 mg/kg IV every 8 hours for 14 days for skin/mucosa disease and 21 days for disseminated or CNS disease. The alternatives use a different threshold, timing, population, or intervention and therefore do not match the clinical facts presented.

Reference: CDC STI Treatment Guidelines: Genital Herpes: https://www.cdc.gov/std/treatment-guidelines/herpes.htm