Dermatology Main 11-20,Q 11,A 25-year-old woman comes to the physician with a rash on her buttocks. The lesions began 10 days ago and are associated with intense itching and burning. She has attempted treatment with cool compresses and calamine lotion without relief. The patient has had occasional diarrhea and unintentional weight loss over the past few months. Her medical history is otherwise unremarkable. Her temperature is 37.1 C (98.8 F), blood pressure is 117/76 mm Hg, pulse is 82/min, and
