Black Toenail: How to Know If Its Cancerous
Published November 16, 2020
If you notice a discoloration in your toenails, you’ll probably just shrug it off. After all, toenails get bruised all the time – especially if you’re a bit clumsy. Besides, it doesn’t really cause much discomfort so what’s the big deal?
But as with any type of discoloration in our body, it’s usually a sign that there’s something wrong. In some cases, it can be a sign that cancer is now wreaking havoc in your toenails. And if not treated early on, it can be deadly.
So how do you know if your black toenail is cancer or not? Read on to find out.
Common Causes of Black Toenail
Toenail discoloration is pretty common. That’s why a lot of people don’t really worry about it that much. Among the usual culprits of black toenails are:
- trauma from injury
- repeated trauma (usually a result of constantly bumping your toes against the front of your shoes)
- blood clot under the nailbed
- bacterial infection
- fungal infection
Though these can cause your toenails to turn an unsightly dark color, they’re not always painful.
But in rare instances, instead of clotting, the blood will pool under your nail bed. This will create pressure between your toe and nail which often results in a smelly discharge.
In even rarer instances, a black toenail can be caused by subungual melanoma. This is a type of malignant tumor that grows under your nailbed causing your toenails to turn black over time.
How to Tell If Its Cancer
Since black toenails look often the same to us, it can be hard to tell if it’s cancer or due to any other causes. Subungual melanoma also develops slowly and has no other symptoms so it only becomes noticeable in its later stages. One study reports that it takes about 2.2 years from the onset of symptoms before a diagnosis can be reached.
But one of the most telling indicators of subungual melanoma is the “Hutchinson’s sign”. This is when the dark stain starts from the nail bed which slowly extends to the cuticles and into the nail folds.
Other symptoms to watch out for include:
- a bruise on the nail that stays in place despite nail growth
- a bruised toenail even without any known injury
- splitting nail or bleeding nail
- nail deterioration (dystrophy)
- skin darkening around the affected nail
- delayed healing of nail lesions or trauma
- painful discharge (pus)
- separation of the nail from the nail bed
In some cases, subungual melanoma won’t cause pigmentation in your toenails. But you may still experience any or all of the other symptoms listed above.
Studies show that it’s a very rare form of cancer, only accounting for 0.7% to 3.5% of all cancerous melanomas worldwide. It mostly occurs in the thumbnails and big toenails, but subungual melanoma can happen on any nail.
Though it’s extremely rare, this type of cancer can be deadly if left untreated. So if you notice the above symptoms, don’t hesitate to consult your doctor.
Causes of Subungual Melanoma
As of this writing, scientists are still unsure about what exactly causes subungual melanoma. But like other types of melanoma, it originates in the melanocytes (the cells controlling our pigmentation).
When the melanocytes under our nailbeds produce too much melanin, subungual melanoma occurs.
Though its exact causes remain unclear, the risk factors associated with subungual melanoma are well known. This includes:
- suppressed immune system (such as those diagnosed with HIV)
- a previous injury which caused trauma to the nails
- multiple moles
What to Do If You Have a Black Toenail
First, you need to establish what caused the bruise in your toenail. Remember that nail cancer is very rare. So more than likely, that pigmentation is either caused by trauma or fungal infection.
If it’s caused by an injury, it will go away on its own once the affected nails have grown. But if you can’t remember any recent injury involving your toenails, better consult your doctor.
Black toenails caused by nail fungus can usually be solved with simple home remedies as long as they are detected early. This is why it’s important to talk to your doctor at the onset of symptoms. When a fungal nail infection becomes too severe, the doctor may prescribe an antifungal treatment. If left untreated, it can be deadly too especially if you have diabetes.
If you suspect that your black toenail is due to cancer, call your doctor immediately. They will know how best to deal with it. According to the Canada Dermatology Association, the chances of recovery from subungual melanoma can range from 16% to 80%. The earlier it is detected, the higher are your chances of survival.
About The Author
Judy Ponio is a firm believer in the power of knowledge when it comes to whole body donation and she wants to share her experience with the world. She also loves to write about food and art.