Circumscribed erythematous lesions developed on the back and abdomen of this 19-month-old boy. The rash was mildly pruritic. The parents gave the child 1 dose of diphenhydramine, and the rash resolved after an hour. About 12 hours later, new lesions developed on the face, neck, and upper back. The child was given the same treatment and the symptoms resolved. The following morning, widespread lesions were noted on the child's face, neck, trunk, and extremities.

For 2 days, a 17-year-old boy had a widespread pruritic eruption that involved the trunk and extremities but spared most of the face. Many of the lesions were annular, and they would appear and resolve within 1 day. The patient denied shortness of breath, difficulty in swallowing, and periorbital swelling.