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Mononucleosis — USMLE Step 3 MCQ

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EasyAmbulatory Medicine / Primary CareMononucleosisUSMLE Step 3

A 19-year-old college student has fever, sore throat, fatigue, and posterior cervical lymphadenopathy for 1 week. Examination shows tonsillar exudates and mild splenomegaly. Rapid streptococcal antigen test is negative. CBC shows atypical lymphocytosis. Which of the following is the most likely diagnosis?

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Correct answer: A — Epstein-Barr virus infectious mononucleosis

Fever, exudative pharyngitis, posterior cervical adenopathy, splenomegaly, and atypical lymphocytes indicate EBV mononucleosis.

Reference: CDC Epstein-Barr virus clinical information: https://www.cdc.gov/epstein-barr/