The infection spreads hematogenously either during the primary infection or as a reactivation from a chronic pulmonary focus. Extrapulmonary disease is caused by dissemination and may involve hematopoietic tissues, skin, kidneys, bones, CNS, and myocardium. Extrapulmonary disease or disseminated disease can involve nearly every organ and can be especially fulminant in the immunocompromised host. More often, the disease process is slow, chronic, and may involve viscera and hematopoietic tissues, bones, joints, and meninges. Resulting meningitis takes the form of granulomatous inflammation and may present as either noncommunicating or communicating hydrocephalus.
Coccidioidomycosis is endemic in the western hemisphere from California to Argentina.
Although usually affecting those in endemic areas, coccidioidomycosis is being recognized outside these areas as travelers pass through the areas. Former residents of endemic areas suffer reactivation, and natural disasters such as earthquakes and dust storms create new foci of epidemics. An example of such infectivity was noted following a large California dust storm after which 15 counties reported a tenfold or more increase in cases of coccidioidomycosis. These areas include northern Mexico and Central and South America. Diseases and conditions that alter immune responses also predispose to dissemination and serious disease.