A 55-year-old man presented 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 moxicillin/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. History revealed the following: Medical history: hypertension Medications: hydrochlorothiazide Allergies: none Habits: none Pets: dog Diet: regular Travel: has traveled throughout the Pacific Northwest of the United States Immunizations: up to date Sports/water exposure: hunting Infectious disease exposure: none Physical examination Vital signs: temperature, 99.4° F; pulse, 80 beats/min; respiratory rate, 16 breaths/min; blood pressure, 130/80 mm Hg General: non-ill-appearing HEENT: nickel-sized ulcer on cheek,…