Cutaneous Blastomycosis
A 65-year-old man presented with a 10-month history of a Large expanding facial plaque that was unresponsive to topical and oral antibiotics administered for abscess and folliculitis, as diagnosed on cutaneous biopsy. Previous pulmonary imaging had revealed a pleural effusion and a mass in the lingula; subsequent lung biopsy was inconclusive for tuberculosis. Although results on tuberculin skin testing and cultures were negative, the patient was started on antituberculosis therapy without improvement. Eight months later, the physical examination revealed a plaque on the left side of the face suggestive of a fungal infection (Panel A). Microscopical examination of cutaneous scrapings with potassium hydroxide showed broad-based budding yeast consistent with blastomycosis (Panel B, arrow). There were no pulmonary symptoms, and chest radiography showed no active disease; the mass in the lingula was unchanged. The patient was started on itraconazole pending the results of skin biopsy, which revealed pseudoepitheliomatous hyperplasia with neutrophilic abscesses and a few yeast. Fungal culture confirmed the presence of Blastomyces dermatitidis. At 1-month follow-up, the patient had clinical improvement (Panel C).