Ribs, vertebrae, skull, and distal parts of the long bones are commonly involved. The leptomeninges are frequently involved. In a few patients C. immitis enters the body through broken skin. Microscopically, coccidioidal lesions have a granulocytic as well as mononuclear and macrophage component in an inflammatory infiltrate. The epithelioid cell granulomas can form and become surrounded by fibrous tissue.
Caseous necrosis can occur as well as calcification much like tuberculosis.
In some lesions, endosporulating spherules are found. Following an incubation period of 7 to 28 days, symptoms of fever, malaise, dry cough, chest pain, night sweats, and anorexia may develop. These are all nonspecific symptoms and resemble a episode of influenza. Hemoptysis is not common and is usually associated with cavitary pneumonia. Erythema nodosum or erythema multiforme may occur after the onset of symptoms but are not really specific for coccidiodiomycosis.