A 55-year-old man presented to the physician with a chronic cheek ulcer. The lesion, a reddened nodule measuring 0.5 cm, had developed 2 months earlier.
He was treated with cephalexin, followed by amoxicillin/clavulanate and then with moxifloxacin, but the lesion has not resolved. It ulcerated slowly, without pain, and the patient was eventually referred to the infectious diseases service.