Mr. E, an 83 year old man, presented to the clinic with symptoms of painful blisters on his left anterior back that started 2 days prior. He described the pain as "intense and continuous; like a really bad sunburn. I can't stand clothes touching my skin." He denied fever, chills or cough. Lanacane (Combe, Inc, White Plains, NY) and over the counter pain medicine was ineffective for relief. He was having problems sleeping at night because of the pain and was feeling irritable. His past medical history was remarkable for a chronic atrial fibrillation and recent giant cell arteritis that was treated with prednisone 80 mg for 3 weeks.