(Figure 4.30B, C) - Coccidioides immitis, found in soil of southwestern USA
- Spherules have unencapsulated thick refractile wall
- Infectious arthroconidia inhaled via dust particles
- Types of presentation
- Pulmonary : inhalation of infectious arthroconidia → 40% patients with flu-like symptoms, hilar adenopathy, pulmonary infiltrate, erythema nodosum (favorable prognostic sign)
- Disseminated: <1% cases; targets joints, viscera, brain, skin (pink papules or deep-seated nodules frequently involving face)
- Cutaneous: very rare, due to inoculation; indurated nodule that may ulcerate with sporotrichoid pattern
- Histology: spherules with double refractile, thick walls (20–80 µm) loaded with endospores; diagnostic arthrospores with colony growth showing septate hyphae with infectious, thick-walled barrel-shaped arthroconidia separated by clear spaces (remnants of empty cells)
- Treatment: oral itraconazole, ketoconazole, or fluconazole
| | | | | | Spherules smaller than sporangia in Rhinosporidiosis | | | | | |
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| | | | | | In HIV, lesions may resemble molluscum contagiosum | | | | | |
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| | Figure 4.30
A: Sporothrix schenckii
(Courtesy of Sandra Arduin,
Michigan Department of
Community Health)
B: Coccidioidomycosis*
C: Coccidioidomycosis*
*Courtesy of Dr. Paul Getz |
|
