Fungus

Blastomycosis

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Blastomycosis, Blastomyces dermatidis

  • See Also
  1. Cutaneous Blastomycosis
  2. Fungal Lung Infection
  • Etiology
  1. Blastomyces dermatidis
  • Pathophysiology
  1. Transmitted by exposure to contaminated soil or decomposing timber
    1. Inhalation of spores
    2. Traumatized, non-intact skin exposure (see Cutaneous Blastomycosis)
  2. Endemic regions of United States
    1. Ohio River Basin
    2. Mississippi River Basin
    3. Great Lakes
    4. St. Lawrence River
  • Symptoms
  1. Pulmonary involvement is initially asymptomatic in 50% of cases
  2. Fever
  3. Sweating
  4. Cough
  5. Nocturnal Joint Pain
  • Signs
  1. Acute disease
    1. See Cutaneous Blastomycosis
    2. Self-limited Pneumonia may clear spontaneously in most patients
  2. Disseminated blastomyces lesions (severe cases may be fatal)
    1. Bone
    2. Nervous system
    3. Lungs
    4. Liver
    5. Spleen
    6. Kidney
  1. Test Sensitivity: 66%
  2. Osteolytic lesions
  • Lab
  1. Microscopy
    1. Broad-based budding
  2. Skin lesion Evaluation
    1. Pustular discharge for Potassium Hydroxide
    2. Skin biopsy
    3. See Cutaneous Blastomycosis
  3. Systemic disease
    1. Bone Marrow Aspirate
    2. Sputum
  • Management
  1. Progressive, refractory, or severe disease or Central Nervous System involvement
    1. Amphotericin B 0.5-0.6 mg/kg daily (MAX 2.0 - 2.5g)
  2. Indolent disease
    1. Adults: Itraconazole 200 mg orally daily for 6 months
    2. Children and Pregnant women: Amphotericin B at dosing above
  • Course
  1. Incubation: 30-45 days
  • References
  1. Altman (2007) Am Fam Physician 76:1533-4 [PubMed]
  2. Bradsher (2003) Infect Dis Clin North Am 17:21-40 [PubMed]