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Key Features

Essentials of Diagnosis

  • Residence in, or travel to, an endemic area

  • Primary pulmonary form: fever, chest pain, cough, anorexia, weight loss, and often a macular rash, erythema nodosum, or erythema multiforme

  • Primary cutaneous form: skin trauma followed in 1–3 weeks by an ulcer and regional adenopathy

  • Spherules seen in pus, sputum, CSF, joint fluid; positive culture

  • Appearance of precipitating (early) and complement-fixing antibodies (late)

General Considerations

  • Caused by Coccidioides (immitis or posadasii), which is endemic in the Sonoran Desert areas of western Texas, southern New Mexico and Arizona, southern California, northern Mexico, and South America

  • Infection results from inhalation or inoculation of arthrospores (highly contagious and readily airborne in the dry climate)

  • Human-to-human transmission does not occur

  • More than half of all infections are asymptomatic, and less than 5% are associated with significant pulmonary disease

  • Chronic pulmonary disease or dissemination occurs in less than 1% of cases

Clinical Findings

Symptoms and Signs

  • Primary disease

    • Incubation period is 10–16 days (range, 7–28 days)

    • Symptoms vary from those of a mild fever and arthralgia to severe influenza-like illness with high fever, nonproductive cough, pleuritic chest pains, arthralgias, headache, and night sweats

    • Upper respiratory tract signs are uncommon

    • Signs vary from none to rash, rales, pleural rubs, and signs of pulmonary consolidation

    • Weight loss may occur

  • Skin disease

    • Up to 10% of children develop erythema nodosum or erythema multiforme

    • Less specific maculopapular eruptions occur in a larger number of children

    • Skin lesions can occur following fungemia

    • Primary skin inoculation sites develop indurated ulcers with local adenopathy

    • Contiguous involvement of skin from deep infection in nodes or bone also occurs

  • Chronic pulmonary disease

    • Uncommon in children

    • Manifested by chronic cough (occasionally with hemoptysis), weight loss, pulmonary consolidation, effusion, cavitation, or pneumothorax

  • Disseminated disease

    • More than one organ may be involved

    • Most common extrapulmonary sites involved are

      • Bone or joint (usually a single bone or joint; subacute or chronic swelling, pain, redness)

      • Nodes

      • Meninges (slowly progressive meningeal signs, ataxia, vomiting, headache, and cranial neuropathies)

      • Kidneys (dysuria and urinary frequency)

Differential Diagnosis

  • Primary pulmonary infection resembles acute viral, bacterial, or mycoplasmal infections

  • Subacute presentation mimics tuberculosis, histoplasmosis, and blastomycosis

  • Chronic pulmonary or disseminated disease must be differentiated from cancer, tuberculosis, or other fungal infections


Laboratory Findings

  • Direct examination of respiratory secretions, pus, CSF, or tissue may reveal large spherules (30–60 μm) containing endospores germinating in tissue

  • Periodic acid–Schiff reagent, methenamine silver, and calcofluor stains demonstrate organisms

  • CSF cultures are often falsely negative.

  • Erythrocyte sedimentation rate is usually elevated

  • Eosinophilia may occur, particularly prior to dissemination

  • Antibodies consist of precipitins (usually measurable by 2–3 weeks in 90% of cases and gone by 12 weeks) and complement-fixing antibodies ...

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