A 74-YEAR-OLD CAUCASIAN MAN presented to the hospital with intractable back and chest pain, a diffuse skin rash, and altered mental status. He said that 2 days ago, he'd gone to a different local hospital for treatment of back pain and a headache that had begun 3 days earlier. He was treated with intravenous hydromorphone and sent home with a prescription for meperidine. He said that several hours after being treated with the hydromorphone, the rash developed on his head and then spread to his trunk and upper extremities. WHAT IS YOUR DIAGNOSIS? HOW WOULD YOU TREAT THIS PATIENT?