Coccidioidomycosis (CM) is a fungal disease endemic to the southwestern United States, Northern Mexico, and parts of South America. About 150,000 CM infections are estimated to occur in the United States each year, of which 60% are thought to be asymptomatic. Symptomatic patients typically present with a respiratory syndrome likened to community-acquired pneumonia, while less than 1% of infected individuals are thought to develop refractory disease with or without dissemination. Disseminated infection rarely resolves spontaneously and, although any organ can be affected, tends to involve the skin, lymph nodes, central nervous system and/or the skeletal system. While the risk of disseminated infection is increased in immune suppressed patients, many individuals with no significant prior history have developed debilitating, widespread infection. Causes of refractory and/or disseminated disease in previously healthy individuals have only recently begun to be elucidated, including mutations in the IFNy/IL-12 pathway.