Lung Infection, Coccidioidomycosis

• • Infection occurs by inhalation of 1-10 spores, germination, and rupture causing spread of infection

  • Persistent infection 6-8 wks after primary classified into 5 types:

  • 1. Persistent pneumonia

    2. Chronic progressive pneumonia

    3. Miliary coccidioidomycosis

    4. Coccidioidal nodules

    5. Pulmonary cavities

Epidemiology

• • Pulmonary fungal infections are rising due to widespread use of broad-spectrum antibiotics, immunosuppressive drugs, and HIV infection

  • Occur anywhere in world, some with characteristic endemic areas

  • Coccidioides immitis is endemic to Sonoran life zone (UT, CA, AZ, NV, NM), associated with creosote brush

  • -Dry heat with brief intense rain essential for fungus

    -Spread by strong winds

    -In endemic areas, 30-50% of all pulmonary nodules are coccidiomas

Symptoms and Signs

• • Primary infection is asymptomatic in 60%

  • "Desert fever": Fever, productive cough, pleuritic chest pain, pneumonitis, rash

  • "Desert rheumatism": Desert fever with arthralgias

  • Eosinophilia common (66%)

  • Persistent pneumonia

  • -Fever

    -Productive cough

    -Pleuritic chest pain

    -Consolidation on chest film

    -Resolves < 8 mos

  • Chronic progressive pneumonia

  • -Fever

    -Cough

    -Dyspnea

    -Hemoptysis

    -Weight loss

    -Bilateral apical nodules and multiple cavities

    -Lasting > 10 yrs

  • Miliary coccidioidomycosis: Occurs early and rapidly with bilateral diffuse infiltrates (mortality: 50%)

  • Coccidioidal nodules: 50% asymptomatic; coccidiomas (noncalcified nodular densities) in middle and upper lung fields range from 1 to 4 cm

  • Pulmonary cavities

  • -Affects 15% of patients

    -Typically solitary, thin-walled, located in upper lobes, and < 6 cm

    -50% close spontaneously within 2 yrs

  • Uncommonly, can disseminate in immunocompromised, third trimester pregnancy, darker-skinned people

Laboratory Findings

• • Acutely elevated IgM titers

  • Rising serum IgG titers (seroconversion of 4× rise)

Imaging Findings

• • Chest film: Hilar adenopathy (20%), small pleural effusions (2-20%)

• • Acutely elevated IgM titers

  • Rising serum IgG titers (seroconversion of 4× rise)

  • Skin tests (coccidioidin and spherulin) good for epidemiologic studies, not for diagnosis of acute disease

  • C immitis early to grow in culture but hazardous to handle

  • Spherule identification in tissue, lavage samples helpful in diagnosis

  • Pap staining most sensitive (Gram stains fail to demonstrate spherules)

Rule Out

• • Histoplasmosis

  • TB

• • Chest x-ray

  • Chest CT scan

  • Sputum microscopy and culture

• • Medical therapy not indicated in asymptomatic patients

  • Persistent illness or those at risk for dissemination treat with antifungals

Surgery

• • Resection all diseased tissue, usually with lobectomy

Indications

• • Coccidiomas or cavities where cancer is concern on radiographic imaging

  • Complications of cavities: Hemoptysis, pyopneumothorax

Medications

• • Amphotericin B is standard treatment

  • Fluconazole, ketoconazole, itraconazole for long-term maintenance

Complications

• • 25-50% of those requiring antifungals relapse