A burning red rash

Photo quiz: A 43-year-old man presented with a painful rash on the chest and back. The rash started five days earlier on the left side of the chest and then spread to the left side of the back. The pain was burning in nature. He had no history of a similar rash. He had no exposure to chemicals or physical agents. He had diabetes mellitus, hypertension, and dyslipidemia.

On physical examination, the patient was afebrile. Clusters of vesicles with some pustules and crusting (Figures 1 and 2) were noted on the back and chest. The rest of the body was not affected.