North American Blastomycosis in an Immunocompromised Patient

Blastomycosis is a subacute or chronic deep mycosis caused by a dimorphic fungus, Blastomyces dermatitidis, that generally produces a pulmonary form of the disease and, to a lesser extent, extrapulmonary forms, such as cutaneous, osteoarticular, and genitourinary. Both immunocompetent and immunocompromised individuals can be infected, but more severe disease occurs in the immunocompromised. Blastomycosis can be diagnosed by culture, direct visualization of the yeast in affected tissue, antigen testing, or a combination of these methods. Treatment course and duration depend on the severity of illness. For mild to moderate pulmonary disease, treatment is itraconazole. For severe blastomycosis, lipid-formulation amphotericin B is given, followed by itraconazole. We present an interesting case of cutaneous blastomycosis acquired in Atlanta, Georgia, that looks quite similar to other mycoses, such as coccidioidomycosis and sporotrichosis, and describe its distinguishing features.