Epidemiology of Acute Coccidioidomycosis with Erythema Nodosum (“San Joaquin” or “Valley Fever”)

Abstract

An investigation of 432 cases of "San Joaquin fever," a disease characterized by influenza-like prodromes followed frequently by erythema nodosum, shows on the basis of cultivation of the fungus and sensitivity to coccidioidin, that the infection is caused by Coccidioides immitis. This disease is apparently rarely a contact infection but is acquired by inhalation of the chlamydospores with peak of incidence in the dusty autumn. Most of the inhabitants of the region eventually become infected with Coccidioides.