Clinical Challenge: A Rash About the Umbilicus

A 53-year-old man presents with a skin rash centered around his umbilicus. He describes slight itching and burning and denies symptoms elsewhere. The patient lists his medical history as including "borderline" diabetes. The rash was diagnosed elsewhere as an intertrigo, but the condition failed to respond to a 3-week course of betamethasone dipropionate/clotrimazole cream. The man was subsequently treated with ...