Acanthosis nigricans is a skin condition characterized by regions of dark, velvety discoloration in body folds and creases. The affected skin may get thickened. Most frequently, acanthosis nigricans impacts your armpits, groin, and throat.
The skin changes of acanthosis (ak-an-THOE-sis NIE-grih-kuns) normally happen in individuals that are obese or have diabetes. Kids who develop the illness are at greater risk of developing type 2 diabetes. Paradoxically, acanthosis may be a warning sign of a cancerous tumor in an internal organ, like the gut or liver.
Treatment of underlying conditions can restore some of their standard color and texture into affected areas of the skin.
Acanthosis Nigricans Symptoms
Skin changes are the only signs of acanthosis. You’ll notice dark, thickened, velvety skin in body folds and creases — typically in your armpits, groin, and back of the neck. The skin changes usually appear slowly. The affected skin may also have an odor or itch.
Causes
Acanthosis has been associated with:
- Insulin resistance. Most people who’ve acanthosis also have been resistant to insulin. Insulin is a hormone secreted by the pancreas which enables your body to process glucose. Insulin resistance is exactly what finally causes type 2 diabetes.
- Hormonal disorders. Acanthosis often occurs in people who have disorders such as ovarian cysts, underactive thyroids or problems with the adrenal glands.
- Cancer. Acanthosis nigricans also sometimes occurs with lymphoma or when a cancerous tumor begins growing in an internal organ, such as the stomach, colon or liver.
- Certain drugs and supplements. High-dose niacin, birth control pills, prednisone and other corticosteroids may cause acanthosis nigricans.
Diagnosis
Acanthosis nigricans is usually detected during a skin examination. Rarely, a small skin sample is removed (biopsied) for evaluation in a laboratory. In case the reason behind acanthosis nigricans is uncertain, your physician may recommend blood tests, X-rays or alternative evaluations to search for potential underlying causes.
Treatment
In many situations, treating the underlying problem can help fade the discoloration. Examples may include:
- Losing weight. If your acanthosis nigricans is caused by obesity, losing weight may help.
- Stopping medications or supplements. If your condition seems to be related to a medication or supplement that you use, your doctor may suggest that you stop using that substance.
- Having surgery. If acanthosis nigricans was triggered by a cancerous tumor, surgically removing the tumor often clears up the skin discoloration.
