Blastomycosis is a condition caused by the fungusBlastomyces dermatitidis, which most commonly affects the lungs, but can involve other parts of the body. Although it is an important fungal disease in parts of the midwestern and southern central United States, it is very rare in people with HIV and other immunocompromised people. It can be treated effectively with the anti-fungal drugs amphotericin, itraconazole and ketoconazole.