infectious diseases
Coccidioidomycosis
Pathophysiology of Coccidioidomycosis
Coccidioidomycosis is acquired by inhaling spores. Spores are present in soil and can become airborne in dust that can travel downwind. Thus, certain occupations (eg, farming, construction) and outdoor recreational activities increase risk. Epidemics can occur when heavy rains, which promote the growth of mycelia, are followed by drought and winds. Because of travel and delayed onset of clinical manifestations, infections can become evident outside endemic areas. Once inhaled,C. immitisspores convert to large tissue-invasive spherules. As spherules enlarge and then rupture, each releases thousands of small endospores, which may form new spherules. Pulmonary disease is characterized by an acute, subacute, or chronic granulomatous reaction with varying degrees of fibrosis. Lesions may cavitate or form nodular-like coin lesions. Sometimes disease progresses, with widespread lung involvement, systemic dissemination, or both; focal lesions may form in almost any tissue, most commonly in skin, subcutaneous tissues, bones ( Osteomyelitis ), joints, and meninges ( Progressive coccidioidomycosis is uncommon in otherwise healthy people and more likely to occur in the following contexts: HIV infection Use of immunosuppressants Advanced age Second or third trimester of pregnancy or postpartum People who are Filipino, Black, American Indian, Hispanic, or Asian (in decreasing order of relative risk) 