A black area or streak on the big toenail can have multiple causes, and one of them is melanoma.
What are all the things that a black spot or area on the big toenail can possibly mean?
“Fungus, bleeding under the toenail from trauma (talin Noire, runner’s nail), congenital mole, atypical mole, melanoma,” says Dr. David Rahimi, MD, a board-certified dermatologist and cosmetic surgeon.
What are the odds that this sign is melanoma?
Dr. Rahimi says, “Melanoma under the nail is very uncommon.
“I have seen four in 16 years of clinical practice. It is more common in patients with darker skin color: Asian, Hispanics and African Americans.”
Tell-tale features of melanoma?
“If the spot has been there for months, growing in darkness and size, and most importantly:
“Pigmentation in the proximal nail folds — meaning, the color is spilling into the skin portion of the nail. This is called the Hutchinson’s sign.”
Hutchinson’s sign
NOTE: Melanoma in the toenail can occur even if the patient’s foot has had very little lifetime exposure to the sun.
Unlike other forms of melanoma that are typically linked to sun exposure, melanoma in the toenail may arise due to different factors, including genetic predisposition or other internal mechanisms that aren’t even fully known.
Diagnosis requires a biopsy, where a sample of the affected nail or surrounding tissue is examined for cancerous cells.
Unfortunately, there are no known preventive measures for the development of a melanoma in a toenail, whether it’s the big toe or the pinky.
What you can do is make sure you inspect your toenails and feet on a regular basis for any newly-developing dark spots, streaks, lines or smudge-like lesions.
Even if you habitually wear polish, at least make a point to give your toes a good view when it’s time to remove the polish.
Keeping your feet and toenails clean will also help in noticing unusual changes.
Always look at your feet! This includes between the toes and on the soles.
Have a dermatologist inspect your feet once a year.
