Manicurist Shares Warning That a "Black Line" on Nails Could Be a Sign of Skin Cancer

By Jenny Cook

A woman has shared a Facebook post warning people to be vigilant of a little-known sign of cancer.

Beauty technician Jean Skinner of East Sussex, England posted a photo of a client's finger nail with a black line running down the middle, claiming that it can be a sign of melanoma — otherwise known as skin cancer.

Writing on the social media site, Skinner said that the client came in asking for a nail color dark enough to cover the line, thinking it was nothing more than "lack of calcium" or a blood blister. She continued:

"This is melanoma!!! I did not want to frighten her but I told her she needed to see her doctor immediately! She called me today to tell me that yes it was a very aggressive melanoma that has already spread to her lymph nodes!! Her prognosis is not good!(sic.)" 

The post has been widely shared, and Skinner is now urging people to pay attention to any odd changes in their nail beds — despite them often being "nothing to worry about." One reader commented:

"I have recently had top half of my thumb amputated as a result of a black mark on my nail which turned out to be a malignant melanoma. Please take this warning seriously as this form of cancer is very aggressive.(sic)."

Official NHS guidelines state that such dark lines are actually quite common and reassure that — in most cases — they are perfectly normal. However, dark lines should always be checked by a doctor to rule out the possibility of subungal melanoma — a form of skin cancer that affects the nail bed. The NHS website reads:

"Subungual melanoma usually only affects one nail. It will also cause the stripe to change in appearance – for example, it may become wider or darker over time and the pigmentation may also affect the surrounding skin (the nail fold)." 

Speaking to The Sun Dr. Walayat Hussain, a spokesperson for the British Association of Dermatologists, described the photo as a "spot on" example of subungual melanoma. He said:

"It is important to realize there are a lot of other causes of that pigmentation but if it is just in one nail that is a sign that something is going on… It is definitely worth getting checked out by a doctor."