Blastomycosis (North American Blastomycosis) | Figure 4.31
A: Histoplasma capsulatum,
tuberculate macroconidium
(Courtesy of Sandra Arduin,
Michigan Department of
Community Health)
B: Histoplasmosis*
C: Blastomyces dermatitidis*
*Courtesy of Dr. Paul Getz |
| Figure 4.32
A: Blastomycosis*
B: Blastomycosis*
*Courtesy of Dr. Paul Getz
C: Paracoccidiodes brasiliensis
(Courtesy of CDC,
Dr. Lucille Georg) |
(Figures 4.31C and 4.32A, B) - Blastomyces dermatitidis, endemic in Great Lakes, Ohio river basin, and Mississippi river; found mainly in soil
- Two types:
- Primary pulmonary infection: typically asymptomatic or self-limited, can turn into chronic pulmonary (mimics TB or pneumonia), 80% cases with dissemination to skin
- Cutaneous infection: typically due to secondary cutaneous dissemination after pulmonary infection and variable presentation: papulopustules, well-demarcated verrucous plaques with crusting and pustules especially at border, ± central ulceration, healing begins centrally and heals with cribriform scarring
- Histology: round yeast forms with broad-based budding (8–15 µm), thick double-contoured wall, giant cells, and neutrophilic abscesses
- Culture: white fluffy colony at 25°C; yeast cell with double-contoured thick walls, broad base, and typical single budding at 37°C; conidia on conidiophores resembling lollipops
- Treatment: oral antifungal (itraconazole, ketoconazole), if severe or progressive use amphotericin B
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