ESSENTIALS OF DIAGNOSIS
Acute infection: influenza-like illness, fever, backache, headache, fatigue, and cough; erythema nodosum is common.
Dissemination may result in meningitis, bony lesions, or skin and soft tissue abscesses; common opportunistic infection in AIDS.
Chest radiograph findings vary from pneumonitis to cavitation.
Serologic tests useful; large spherules containing endospores demonstrable in sputum or tissues.
Coccidioidomycosis should be considered in the diagnosis of any obscure illness in a patient who has lived in or visited an endemic area. Infection results from the inhalation of arthroconidia of Coccidioides immitis or C posadasii; both organisms are molds that grow in soil in certain arid regions of the southwestern United States, in Mexico, and in Central and South America. Cases are now being reported from southeastern Washington and Colorado, areas of the United States that have not previously been considered to be endemic for this organism. Less than 1% of immunocompetent persons show dissemination, but among these patients, the mortality rate is high.
In patients with AIDS who reside in endemic areas, coccidioidomycosis is a common opportunistic infection. In these patients, disease manifestations range from focal pulmonary infiltrates to widespread miliary disease with multiple organ involvement and meningitis; severity is inversely related to the extent of control of the HIV infection.
Symptoms of primary coccidioidomycosis occur in about 40% of infections. Symptom onset (after an incubation period of 10–30 days) is usually that of a respiratory tract illness with fever and occasionally chills. Coccidioidomycosis is a common, frequently unrecognized, etiology of community-acquired pneumonia in endemic areas.
Arthralgia accompanied by periarticular swelling, often of the knees and ankles, is common. Erythema nodosum may appear 2–20 days after onset of symptoms. Persistent pulmonary lesions, varying from cavities and abscesses to parenchymal nodular densities or bronchiectasis, occur in about 5% of diagnosed cases.
Disseminated disease occurs in about 0.1% of White and 1% of non-White patients. Patients who are Filipino or Black are especially susceptible, as are pregnant women of all races. Any organ may be involved. Pulmonary findings usually become more pronounced, with mediastinal lymph node enlargement, cough, and increased sputum production. Lung abscesses may rupture into the pleural space, producing an empyema. Complicated skin and bone infections may develop. Fungemia may occur and is characterized clinically by a diffuse miliary pattern on chest radiograph and by early death. The course may be particularly rapid in immunosuppressed patients. Clinicians caring for immunosuppressed patients in endemic areas need to consider that patients may have latent infection.
Meningitis occurs in 30–50% of cases of dissemination and may result in chronic basilar meningitis. Subcutaneous abscesses and verrucous skin lesions are especially common in fulminating cases. Lymphadenitis may occur and may progress to suppuration. Patients with ...