A 31-year-old incarcerated man sought care for one crusted ulcer and one adjacent open ulcer with granulation tissue on his left malleolus. The ulcers were caused by chronic venous insufficiency—the result of previous trauma to the ankle. Concerned that the ulcers would become infected, the physician prescribed one double-strength tablet twice a day of trimethoprim-sulfamethoxazole (TMP-SMX). The patient took 2 doses of the antibiotic and one dose of naproxen.
When the patient awoke the next morning, he had a generalized skin eruption on his chin, trunk, buttocks, glans penis, and extremities (FIGURE). The rash began as red edematous plaques that became itchy and painful with dark, violaceous dusky centers surrounded by redness. The patient was treated with topical hydrocortisone 2.5% twice a day and oral diphenhydramine 25 mg followed by 50 mg, but the rash didn’t improve.
The patient was transported to the local emergency department where physicians noted that the patient had about 30 to 40 well-demarcated papules and plaques of various sizes that were haphazardly located over the patient’s chin, chest, back, upper and lower extremities, and genitalia. There was one lesion on the chest with central vesiculation. There were no lesions on the mucous membranes of his eyes, ears, nose, mouth, or anus.
The patient, whose vital signs were within normal limits, was empirically treated with one dose of methylprednisolone (125 mg intravenous [IV]) and started on IV piperacillin-tazobactam and vancomycin. Lab work revealed no elevation in his white blood cell count, creatinine, liver function enzymes, or C-reactive protein.
The patient subsequently revealed that he’d had a similar experience a year earlier after being treated with TMP-SMX for cellulitis. He noted that during the previous episode, the lesions were located on the exact same areas of his glans penis and chin.
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