FREDERIC B.ASKINMDWILLIAM H.WESTRAMD
Copyright 2002 American Medical Association. All Rights Reserved. Applicable FARS/DFARS Restrictions Apply to Government Use.2002
Blastomycosis is a rare systemic mycoses caused by the dimorphic fungus Blastomyces dermatitidis. It exhibits a widely variable clinical presentation and is potentially life threatening. In the United States, blastomycosis is endemic to the Mississippi and Ohio River valleys, the Great Lakes region, and a small area of New York bordering the St Lawrence River. Epidemics from point-source infections have also been reported, and ususally occur in regions with moist, highly organic soil.1 The fungus is thermally dimorphic, existing in a mycelial phase in soil and transforming into a yeast in the human body. Gilchrist reported the first case in 1894,2 initially characterizing it as a protozoan skin infection. Shortly thereafter, he changed his original description and gave the fungus its current name. Subsequently, it was noted that the primary infection occurred in the lungs2 and that skin is a secondary site. Except for rare reports of traumatic cutaneous inoculation, nearly all cases are currently attributed to a pulmonary portal of entry.3 This airborne mode of transmission is a feature that is shared with the other systemic mycoses that exhibit head and neck involvement: histoplasmosis and paracoccidioidomycosis (previously termed South American blastomycosis).
Diagnosis Pathology Quiz Case. Arch Otolaryngol Head Neck Surg. 2002;128(7):854. doi: