While a brown or black band of pigment in one or more nails could also simply be a benign mole, it’s best to book a visit to the derm just in case, Feely notes. It’s known as Hutchinson’s sign, and it most commonly occurs on your thumb (or big toe), according to The New England Journal of Medicine. If you notice pain, bleeding, or splitting of the nail, make an appointment with a board-certified dermatologist who may have to do a biopsy on the nail, she says.Īn especially concerning sign? If the skin surrounding the lower part of your nail turns brown or black - this heightens suspicion for a melanoma, says Meghan Feely, M.D., a board-certified dermatologist based in New York City and New Jersey and clinical instructor at Mount Sinai. “While nail melanomas are uncommon, they can be deadly if not diagnosed and treated early.”
the most serious form of skin cancer), says Shari Lipner, M.D., Ph.D., a dermatologist and director of the nail division at Weill Cornell Medicine. “If your nail is brown or black, the most important thing to worry about is a nail melanoma,” (a.k.a.
