+
Source: Carver PL. Invasive fungal infections. In: DiPiro JT, Talbert RL, Yee GC, Matzke GR, Wells BG, Posey LM. Pharmacotherapy: A Pathophysiologic Approach. 10th ed. New York, NY: McGraw-Hill; 2017. http://accesspharmacy.mhmedical.com/content.aspx?bookid=1861§ionid=146073167. Accessed March 14, 2017.
++
++
++
Pulmonary infection probably occurs by inhalation of conidia, which convert to yeast form in lung.
Inflammatory response, followed by cell-mediated immunity and formation of noncaseating granulomas.
++
B. dermatitidis considered to be soil inhabitant, though attempts to isolate it in nature have frequently been unsuccessful.
Has been found in soil containing decayed vegetation, decomposed wood, and pigeon manure.
Found in southeastern, south central, and midwestern United States as well as Canadian provinces that border the Great Lakes.
++
No sex, age, or occupational predilection.
Review of sporadic cases suggests that people with outdoor occupations that expose them to soil at highest risk.
+++
CLINICAL PRESENTATION
++
Colonization does not occur.
Can disseminate to virtually every other body organ, including skin, bones, and joints, or the genitourinary tract, without evidence of pulmonary disease.
Acute pulmonary blastomycosis.
Generally asymptomatic or self-limited disease.
Characterized by fever, shaking chills, and productive, purulent cough, with or without hemoptysis in immunocompetent individuals.
Difficult to differentiate from other respiratory infections based on symptoms.
Sporadic pulmonary blastomycosis.
More chronic or subacute disease.
Characterized by low-grade fever, night sweats, weight loss, and productive cough resembling that of TB rather than bacterial pneumonia.
Chronic pulmonary blastomycosis.
Characterized by fever, malaise, weight loss, night sweats, chest pain, and productive cough.
Evidence of disseminated disease can appear 1–3 years after resolution of primary pneumonia.
+++
MEANS OF CONFIRMATION AND DIAGNOSIS
++
Direct microscopic visualization of large, multinucleated yeast with single, broad-based buds in sputum or other respiratory specimens, following digestion of cells and debris with 10% potassium hydroxide.
No reliable skin test available.
++
++
Chest radiograph.
CT scan.
+++
DIAGNOSTIC PROCEDURES
++
+++
DIFFERENTIAL DIAGNOSIS
++
Tuberculosis
Bacterial pneumonia.
Malignancy.
Other fungal infection.