Protothecosis | Figure 4.34 A: Mucormycosis (Courtesy of Dr. Paul Getz) B: Rhinosporidiosis* C: Rhinosporidiosis* *Reproduced with permission from: Kumari R, Laxmisha C, Thappa, DM. Disseminated cutaneous rhinosporidiosis. Dermatol Online J. Mar 2005;11 (1) :19 D: Protothecosis (Courtesy of Sandra Arduin, Michigan Department of Community Health) |
(Figure 4.34D) - Prototheca wickerhamii, an achlorophyllic algae found in stagnant aqueous sources (lakes, stream, even tap water)
- Endemic to Southeast Asia
- Presents after traumatic inoculation as solitary cutaneous plaque or nodule typically involving an extremity, may evolve to umbilicated papules in HIV patients; may also present as olecranon bursitis; immunocompentent patients with limited disease but an immunocompromised person may have widespread disease, including algaemia
- Histology: morula formation (daughter cells within a theca resembling a soccer ball), 6–10 µm either outside or within macrophage, best seen with GMS or PAS; inhibited by cycloheximide
- Treatment: excision or tetracycline with amphotericin B
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