Volume 86, Number 10 www.aafp.org/afp American Family Physician 953 A 72-year-old woman presented with a painful erythematous rash on her right upper back that had developed seven days earlier. The rash spread over the next two days into her right axilla and breast (Figures 1 and 2). The lesions started as red, swollen, tender patches with clear vesicles and bullae, and then became hemorrhagic after three days. She had no fever or chills. Her medical history included hypertension and rheumatoid arthritis. She was taking enalapril (Vasotec) and prednisone. Physical examination showed vesicular lesions in a band from back to front on her right side. She was treated with amoxicillin for seven days, but the rash did not improve. After a few days, the patient reported a burning and lancinating pain in the area of the rash that was elicited with even slight pressure, such as touching clothes or bedsheets.