Coccidioidomycosis

Source: Carver PL. Invasive Fungal Infections. In: DiPiro, JT, Talbert RL, Yee GC, Matzke GR, Wells BG, Posey LM. Pharmacotherapy: A Pathophysiologic Approach. 8th ed. http://accesspharmacy.com/content.aspx?aid=8005562.

• Systemic fungal infection

• Systemic fungal infection caused by Coccidioides immitis

• Arthroconidia inhaled after contact with contaminated soil.
• Transformed into spherules, which reproduce and produce endospores.
• Endospores released, stimulating acute inflammatory response.
  • Tissue infiltrated by mononuclear cells, resulting in granuloma formation.

• Coccidioides immitis grows in soil as mold
• Endemic regions encompass semiarid areas of southwestern United States from California to Texas

• No risk factors for primary disease, but factors that affect risk of subsequent dissemination of disease are summarized in Table 1.

• Spectrum of illnesses ranging from primary uncomplicated respiratory tract infection that resolves spontaneously to progressive pulmonary or disseminated infection.
• 60% of patients asymptomatic; 10- to 30-day incubation period.

Signs and Symptoms

• Nonspecific symptoms often indistinguishable from those of ordinary upper respiratory infections:
  • Fever
  • Cough
  • Headache
  • Sore throat
  • Myalgias
  • Fatigue
  • Fine, diffuse rash may appear during first few days of illness
• Chronic, persistent pneumonia or persistent pulmonary coccidioidomycosis (primary disease lasting >6 wk)
  • Complicated by hemoptysis, pulmonary scarring, and formation of cavities or bronchopleural fistulas.
• “Valley fever” (25% of patients)
  • Syndrome characterized by erythema nodosum and erythema multiforme of upper trunk and extremities in association with diffuse joint aches or fever.
• Disseminated infection (<1% of patients)
  • Dissemination may occur to skin, lymph nodes, bone, meninges, spleen, liver, kidney, and adrenal gland.
    • Central nervous system (CNS) infection occurs in ~16% of patients with disseminated infection.
    • Symptoms subtle and nonspecific

Means of Confirmation and Diagnosis

• Direct microscopic examination and histopathologic studies of infected tissues or secretions provides accurate and rapid method of diagnosis.
• Positive skin test develops in most patients within 3 weeks of symptom onset.

Laboratory Tests

• Culture secretions
• Serologic testing
  • Immunoglobulin M to C. immitis peaks within 2–3 weeks of infection, then declines rapidly.
  • Immunoglobulin G peaks in 4–12 weeks and declines ...