A 32-year-old man presents to a clinic for evaluation of a rash. He denies taking any new medications and reports 2 new male sex partners in the last 8 weeks. The rash began several days prior as an erythematous, maculopapular rash on the chest and back (Figure 1) and now also involves the palms and soles. He does not have any ocular, otic, or neurologic symptoms. Serologic testing for syphilis and HIV is ordered. He does not report any drug allergies.