A Patient With Fever and Rash

(See pages 136–7 for the Answer to the Photo Quiz.) A 20-year-old man presented to the emergency department in May 2013 with a new rash that had gradually progressed over 1 day. He also noted several days of sore throat, fever, malaise, and cervical lymphadenopathy preceding the rash. He lived in Maryland, his medical history was unremarkable, and he denied any new medications. On physical exam, he had enlarged tonsils and cervical lymphadenopathy. He had no hepatosplenomegaly. In addition, his skin showed erythematous papules too numerous to count, as well as plaques of varying size and morphology on his face, trunk, palms, and extremities, yet there were no lesions on his mucus membranes or genitals (Figures ​(Figures11–3). The lesions were nonblanching and mildly pruritic. Initial laboratory evaluation in the emergency department was only significant for an alanine aminotransferase level of 127 U/L (normal range, 0–41 U/L) and an aspartate aminotransferase level of 48 U/L (normal range, 0–40 U/L). Figure 2. Skin lesions on trunk. Figure 1. Skin lesions on trunk. Figure 3. Skin lesions on hands. What is your diagnosis?