Tinea nigra is a caused by a superficial fungal skin infection caused by a dematiaceous fungus.
Fungus: Hortaea werneckii
The fungus tends to be found in hypersaline environments (sea, salt marsh, etc) in the tropics or subtropics.
Clinical features:
(1) it can be seen in children, adolescents or adults.
(2) it presents as an asymptomatic brown-colored macules, often palmoplantar or involving the digits
Fungal colonies are greenish brown to black.
Microscopic exam of a skin scraping shows septate hyphae. On culture there are yeast forms that undergo binary fission.
The differential diagnosis includes nevi or other melanocytic skin lesions.
To read more or access our algorithms and calculators, please log in or register.
Specialty: Infectious Diseases
