Sean M. Roth, MD

A 56-year-old man presents with diffuse erythema. He has not changed his routine or eaten anything unusual. The rash initially appeared the previous night as asymptomatic erythema on the face and body. On awakening in the morning, the patient noticed that the erythema had spread over most of his body and had become pruritic. Over-the-counter diphenhydramine did not relieve the symptoms.