Rare tropical fungus randomly blooms in the palm of a US teen’s hand
Enlarge / The palm of this patient's left hand exhibited a brown, discolored, irregularly shaped patch of skin, which had been diagnosed as a case of tinea nigra, caused by the fungus Hortaea werneckii. (credit: CDC | Dr. Lucille K. Georg)
If your palms are a tad sweaty, it might be a good idea to go wash them now, before reading further.
A 19-year-old university student in Philadelphia had a surprising firsthand encounter with a rare tropical black fungus, which was found sprouting into a large, dark circle in the palm of her hand. Her case was reported today in the New England Journal of Medicine.
The dark mark at hand is called tinea nigra, a very uncommon superficial fungal infection that typically strikes people in humid, tropical, or subtropical coastal areas-and often people in those areas with particularly sweaty palms. The fungus behind nearly all cases is Hortaea werneckii, a warm-dwelling, salt-loving yeast-like fungus that lives in the environment and produces a dark pigment. When grown in petri dishes in labs, H. werneckii forms creamy, stark-black yeast-like colonies that eventually become filamentous.