Abstract
In histoplasmosis massive infection leads to multiple primary foci, but does not produce larger or progressive lesions. Dogs, contrary to men, can develop a carrier state with viable organisms in "normal" lymph nodes. In coccidioidomycosis the primary lesion is generally solitary. The primary complex in coccidioidomycosis lacks the lymph node component repeatedly, which is also seen in canine but not in human histoplasmosis. Histoplasmosis commonly leads to benign, seldom to progressive dissemination during primary infection. In coccidioidomycosis, post-primary dissemination is dangerously progressive.