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  • Fungus: Blastomyces dermatitidis
  • Lives in moist soil, wooded areas
    • Spores are airborne
  • North, Central and South America
    • Southeast and Midwest US (Mississippi and Ohio River valleys)
  • Causes a systemic pyogranulomatous infection
  • Reportable disease

Clinical Features

  • Up to 50% of cases will be asymptomatic
  • Incubation period: 3-6 weeks
  • Flu like symptoms: Fever, chills, cough, muscle aches, joint pain, chest pain
  • Other systemic symptoms: Weight loss, night sweats, chills
  • Pulmonary: most common
    • Acute or chronic pneumonia
    • Diffuse pneumonitis, ARDS
  • Skin:
    • Verrucous lesion with irregular borders
    • Microabscess (cold), subcutaneous nodules like erythema nodosum
    • Ulcers that bleed easily and well-demarcated
  • Bone: Osteomyelitis, chronic draining sinus, paravertebral abscess
  • Genitourinary: Prostatitis, Epididymorchitis
  • CNS: Meningitis, epidural abscess Brain abscess in immunocompromised
  • Can involve breast, adrenal, thyroid, eye, lymph node, liver, spleen

Differential Diagnosis



  • Fungal culture (Blood, sputum, bone marrow, liver or skin) : Broad based buds
  • Antigen test (Serum or urine)
  • Histopathology
  • Serologic testing
  • HIV testing
  • CXR: Alveolar infiltrates +/- cavitation, mass lesions, miliary or reticulo- or fibronodular pattern, pleural effusions, upper lobe infiltrate, perihilar lymph nodes
  • Chest CT: Nodules, consolidation +/- cavitation, tree-in-bud opacities, pleural effusion, lack hilar adenopathy
  • Xray of bone: Well-circumscribed osteolytic lesion
    • Xray vertebrae: Lytic lesion in anterior vertebral body and destruction of disc space
  • Bronchoscopy


  • ID consult
  • Mild or moderate infections: Itraconazole (200mg TID x 3 days then once or twice daily x 6-12 months)
  • Severe infection: Amphotericin B (Lipid 3-5mg/kg IV daily or deoxycholate 0.7-1mg/kg IV daily)
    • All immunocompromised patient should receive amphotericin B
    • Lipid for all patients, except children
    • If CNS involvement, lipid for all patients


  • Subclinical disease: Observation and no treatment
  • Patients with immunosuppression or progressive pulmonary or extrapulmonary symptoms need treatment and often admission
  • Some may need ICU

See Also

External Links