African histoplasmosis was initially described in Central and West Africa, but patients have been identified in Asia, Europe and South America.
Species: Histoplasma capsulatum var. duboisii (Hcd)
Classic distribution:
(1) Africa from 20 degrees north to 20 degrees south of the equator
(2) Madagascar
Risk factors:
(1) HIV-positive
(2) cave explorer or other exposure to bat guano
(3) environmental exposures, including mud baths
Clinical features:
(1) localized - cutaneous, subcutaneous tissues, bone, oral cavity
(2) disseminated disease
Biopsy of a lesion should show chronic granulomatous inflammation with giant cells and yeast forms.
Differential diagnosis:
(1) Histoplasma capsulatum var capsultum (also present in Africa)
(2) Mycobacterial infections
(3) other deep fungi
(4) malignant tumor