ABSTRACT
Dimorphic fungi Dimorphic fungi comprise a diverse group of fungi characterized by mycelial growth at 22°C, but development of yeast forms at 35–37°C. Sporotrichosis is an infection of subcutaneous tissue with Sporothrix shenckii, usually on the arms or hands after a contaminated inoculation injury. Histoplasma capsulatum (causing the infection histoplasmosis) is principally found in North, Central and South America. The natural reservoir is soil contaminated by bird or bat droppings. Histoplasmosis is usually an asymptomatic or mild, self-limiting chest infection, but chronic pulmonary infection (resembling tuberculosis) and disseminated infection (in immunosuppressed patients) can occur. Coccidioides immitis is a soil fungus found in South Western USA and some parts of Central and South America. Inhalation of airborne spores can cause asymptomatic or mild pulmonary infection, but occasionally chronic pulmonary or disseminated disease occur. Other geographically restricted dimorphic fungi with similar clinical features include Blastomyces dermatitidis (North, Central and South America) and Paracoccidioides brasiliensis (South America).
