Have you ever looked at your toenail and notice a dark line on the nail? Well, that mark can be harmless or it can be cancer. Get it checked out. Melanonychia (mel'-a -no-nik'-e-) is a tan, brown or black lengthwise streak or line on the nail plate. Melanonychia occurs because of increased production of melanin by melanocytes in the nail matrix (growing cells).
Melanonychia most commonly occurs in people with darker skin color. Among people of African heritage, "racial" melanonychia affects up to 77 percent of young adults over the age of 20 and almost 100 percent of those older than 50 years of age. The condition is less common in other races and affects males and females equally and increases with age. One or more of the toes may be involved but the big toe is the most common site for the melanonychia. Approximately two thirds of cases have a brown-black color, and one third of cases have a lighter color. The width of the band can vary from 1 millimeter to several millimeters. The bands are wider than 3 millimeters in greater than 50 percent of people. The wider and darker the bands are, the more concerning they are.
There are many causes of melanonychia including medications -- inflammatory disorders, trauma, fungal infections and systemic diseases. The most concerning cause of melanonychia is melanoma (cancer) of the nail. Thankfully only a small number of people with longitudinal melanonychia will have subungual (nail) melanoma.
Symptoms
Person with melanonychia will usually come to the doctor with a history of a tan, brown or black lengthwise streak or line on the nail that extends from the back of the nail or cuticle area to the free end of the nail. There is usually no pain, itching, or burning.
These streaks may be common and often people will say they had the dark bands on the nail for a long time. It is still recommended that they see a podiatrist to have it checked out anyway.
When you see the podiatrist, a careful history will be taken and will include information on the medications taken, past treatments, hobbies, illnesses, family history, any history of trauma to the area, prior history of a biopsy of the nail, number of nails affected, results of any prior nail clippings sent for examination under a microscope, results of cultures sent for infectious organisms, change of appearance of the band over time.
After seeing the podiatrist, they will most likely biopsy the nail to determine whether or not the melanonychia is benign (not cancerous) or malignant (cancerous). With these melanonychia there's no guarantee that it is benign unless you look at it under a microscope.
On the other hand with toenail melanoma, there is a long-standing history of melanonychia that recently changed in appearance. Changes that are cause for concern include changes in the color, pattern, or size of the band, new onset of pain or ulceration in the site of the melanonychia, or the presence of blood under the nail. Other signs of melanoma may be melanonychia developing abruptly in a previously normal nail plate and pigment streak getting suddenly darker or wider.
Treatment
For the majority of the cases of melanonychia there is no treatment needed.

When treatment is needed, it is based on the cause of the condition. If the melanonychia is secondary to a systemic condition and/or dermatologic disease, treatment of the underlying condition is helpful. If melanonychia is secondary to a drug, discontinuation of the offending agent may result in clearance. If there is any concern about the melanonychia being melanoma (cancerous) the podiatrist will perform a nail biopsy so it can be looked at under a microscope. After seeing the podiatrist and it is determined that the melanonychia is benign, it doesn't mean that it will always be harmless. Similar to a mole on the skin, the nail and the band should be checked regularly for changes that may indicate they are no longer harmless.
o If you have a streak on your toe nail and you are concerned about it, you should see a podiatrist to have it examined. For more information, visit www.foothealthfacts.org or to find a local podiatrist call or visit Bahamas Foot Centre on Rosetta Street, telephone 325-2996 or Bahamas Surgical Associates on Albury Lane, telephone 394-5824.

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