Coccidioidomycosis

Background

• Fungal infection caused by Coccidioides immitis and C posadasii
• Organisms found in soil in arid climates of southwestern US and nearby areas
• Transmitted by inhalation of airborne spores
• Also known as Valley Fever

Clinical Features

• Often asymptomatic
• Most commonly affects lungs
• Mild ILI 1-4 weeks after exposure
  • Fever
  • Sore throat
  • Cough
  • Headache
  • Fatigue
  • Pleuritic chest pain
• More severe presentation
  • Fever
  • Arthralgias
  • Erythema nodosum or erythema multiforme
  • Chest pain
• Rarely, respiratory failure
• Disseminated disease, more common in immunosuppressed
  • Dramatic sweats
  • Dyspnea at rest
  • Fever
  • Weight loss
  • 50% develop meningitis

Differential Diagnosis

• Acute respiratory distress syndrome
• Blastomycosis
• Enteropathic arthropathies
• Eosinophilic pneumonia
• Histoplasmosis
• Lung abscess
• Lung cancer
• Lymphoma
• Myelophthisic anemia
• Old granuloma
• Paracoccidioidomycosis
• Pericarditis (acute or chronic)
• Pneumocystis jiroveci pneumonia
• Sarcoidosis
• Solitary pulmonary nodule
• TB

Workup

• Basic workup
  • Typically normal WBC count or mild lymphocytosis, monocytosis, and/or eosinophilia (>5%)
  • Elevated ESR
  • CXR
  • LP if suspect meningitis
• Special testing
  • Immunoglobulin testing
  • Culture
  • PCR testing
  • Skin testing

Treatment

• Often self-limited mild disease not requiring treatment
• Azoles first line
• Treatment options
  • Itraconazole - 200 mg 2-3 times/day orally
  • Fluconazole - 400-800 mg/day orally or IV
  • Ketoconazole - 400 mg/day orally
  • Amphotericin B deoxycholate - 0.5-1.5 mg/kg/day IV
  • Lipid formulations of amphotericin B - 2-5 mg/kg/day IV

Sources

emedicine