A 7-month-old male is bro...

A 7-month-old male is brought to the emergency department for evaluation of pustules and inflamed papules on the scalp and extremities for several weeks of duration. The parents report the lesions started about a month prior and he has already been treated with cephalexin, clindamycin, and sulfamethoxazole without any improvement. Cultures sent prior by the child's pediatrician did not reveal any fungus or bacteria. The parents report a low-grade fever for about 3 days.