Comments
INITIAL SYMPTOMS:
Asymptomatic: 60% of infected; Flu-like illness with fever, cough, pleuritic chest pain; Some have arthralgias and skin manifestations (maculopapular rash, erythema multiforme, and erythema nodosum;. [Harrison, p. 754-5]
FINDINGS
Coccidioidomycosis usually begins with a flu-like respiratory illness. Erythema nodosum develops in about one fifth of clinically recognized cases. Primary infection 1) heals completely; 2) leaves residual fibrosis and a pulmonary nodule (sometimes calcified); or, 3) progresses (<1 % of symptomatic cases) to the disseminated form of the disease: lesions in all parts of body including skin, bone, and brain. [CCDM, p. 116] Patients may have, in decreasing order of frequency, fever, cough, chest pain, sputum production, sore throat, and hemoptysis. [Merck Manual, p. 1328] Nonspecific rashes, as well as erythema nodosum and erythema multiforme (vesicles), may appear at the time of the primary infection. Patients may have arthralgias, "desert rheumatism," at this time. Primary lung infection may progress to pneumonia, pleural and pericardial effusions, hemoptysis, and pulmonary nodules. [ID, p. 2231-4] In AIDS and transplant patients and in immunocompetent patients with heavy exposures, severe pneumonia may progress to ARDS. [Cohen, p. 332] Immune thrombocytopenia may occur. [Guerrant, p. 578]
EPIDEMIOLOGY:
Handling mold cultures in the laboratory is extremely hazardous. Because of occupational exposure, males are more frequently affected than females. Coccidioidomycosis is not directly transmitted from animal to human or from human to human. There is a high prevalence of positive reactors in endemic areas. Reactivation can occur in those who become immunosuppressed therapeutically or by HIV infection. [CCDM, p. 117] Calculations predict that there are 150,000 new cases annually in the heavily populated areas of southern Arizona and southern central California. About 1/2 to 2/3 of patients are mildly infected and do not seek medical attention. Most infections are self-limited and without sequelae. The most commonly diagnosed syndromes in normal hosts are: 1.) Early respiratory infection; 2.) Pulmonary nodules and cavities, and; 3.) Extrapulmonary dissemination (0.5% of all infected people). [PPID, p. 2976-80] Rates of infection are increased during the driest months and when more dust from wind or construction. [Cecil, p. 1979]
LABORATORY DIAGNOSIS:
IgM antibodies can be detected soon after infection and persist for weeks. Coccidioides from sputum and tissue samples grows on standard media (blood agar) within 3-7 days. Since it is hazardous if inhaled by laboratory workers, alert the lab that Coccidioides is suspected. [Harrison ID, p. 1077] Tube precipitin antibodies can be detected in 90% of patients during the first 3 weeks of symptoms. [PPID, p. 2981] Coccidioidal meningitis can be diagnosed by detection of CF antibodies in the CSF. [Cecil, p. 1981]
DISSEMINATED DISEASE:
Disseminated infection usually occurs within six months of the primary infection. Manifestations of disseminated infection include verrucous skin lesions, cerebral abscesses, infectious arthritis, lymphadenitis, kidney infection, chorioretinitis, liver abscesses, epididymo-orchitis, and infections of the uterus, tubes, and ovaries. [ID, p. 2231-4] Immunocompromised patients are at increased risk for dissemination. Many patients with extrapulmonary dissemination have normal chest x-rays. Disseminated disease occurs most commonly in the skin (including keratotic and verrucose ulcers), the bones and joints, and in the meninges. [PPID, p. 2979] Women in 2nd and 3rd trimesters of pregnancy are at increased risk. [Harrison ID, p. 1077]
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