Tinea Nigra | Figure 4.21
A: Pityriasis versicolor
(Courtesy of Dr. Paul Getz)
B: Tinea nigra
(Courtesy of Dr. Marcus
Henrique de Sousa Brito
Xavier, Brazil)
C: Piedra
(Courtesy of Doctor Fungus,
www.doctorfungus.org) |
(Figure 4.21B) - Dematiaceous fungus: Hortaea werneckii (formerly known as Exophiala werneckii, Phaeoannellomyces werneckii, and Cladosporium werneckii)
- Geophilic: transmission likely acquired via direct contact with soil or decaying vegetation
- Presents as one or more sharply demarcated hyperpigmented to gray macules or patches with fine scale on the palms or soles; can be mistaken for melanoma (but former has advancing border with darker pigmentation compared to center)
- Pigment within stratum corneum (scrapes off easily) and golden brown hyphae seen on KOH; black shiny colony on culture
- Treatment: topical imidazoles or allylamines
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