Skin changes are the only signs of acanthosis nigricans. 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.
When to see a doctor?
Consult your doctor if you notice changes in your skin — especially if the changes appear suddenly. You may have an underlying condition that needs treatment.
Acanthosis nigricans has been associated with:
Insulin resistance - Most people who have acanthosis nigricans have also become resistant to insulin. Insulin is a hormone secreted by the pancreas that allows your body to process sugar. Insulin resistance is what eventually causes type 2 diabetes.
Hormonal disorders - Acanthosis nigricans often occurs in people who have disorders such as ovarian cysts, underactive thyroids or problems with the adrenal glands.
Certain drugs and supplements - High-dose niacin, birth control pills, prednisone and other corticosteroids may cause acanthosis nigricans.
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.
Acanthosis nigricans risk factors include:
- Obesity - The heavier you are, the higher your risk of acanthosis nigricans.
- Race - Studies show that in the United States, acanthosis nigricans is more common among Native Americans.
- Family history.
Some types of acanthosis nigricans appear to be hereditary.
People who have acanthosis nigricans are much more likely to develop type 2 diabetes.
