Antimicrobials USMLE Step 1 Practice Question
A 5-year-old boy with acute bacterial meningitis due to Streptococcus pneumoniae is treated with ceftriaxone and vancomycin. On hospital day 2, he develops a diffuse maculopapular rash sparing palms and soles, fever (39.2°C), and arthralgias. Vital signs show HR 118/min, BP 105/68 mmHg, RR 24/min. WBC is 14,200/μL with left shift. He denies recent antibiotic allergies. Which medication is most likely responsible for this reaction, and what is the recommended management?
Answer choices
- AStevens-Johnson syndrome; discontinue ceftriaxone and treat supportively
- BAnaphylaxis; administer epinephrine and airway support
- CDrug fever from impure ceftriaxone preparation; switch to alternative antibiotic
- DSerum sickness-like reaction; continue ceftriaxone with antihistamine supportCorrect answer
- EMeningococcemia; switch to vancomycin immediately
- FToxic epidermal necrolysis; discontinue vancomycin and initiate systemic corticosteroids
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