What is Acanthosis Nigricans?

Light brown or black skin patches may be a sign of acanthosis nigricans. This treatable skin disorder isn’t contagious or dangerous. However, it can be a sign of diabetes, so talk to your healthcare provider. Often, treating diabetes (or another underlying cause) causes the skin to clear up.

What is acanthosis nigricans?

This skin disorder results in light-brown-to-black spots. It often happens to otherwise healthy people, but in some cases, it may be a sign of an underlying condition. The markings look like a spot or stain that you might think you can scrub off. But washing will not remove acanthosis nigricans (AN).

Where does acanthosis nigricans appear?

The velvety markings that are characteristic of acanthosis nigricans (a-can-THO-sis NIH-grih-cans) can appear anywhere on the body. They most often show up on the skin folds of the neck, armpits and groin and under the breasts.

Is acanthosis nigricans contagious?

No, AN isn’t contagious. You can’t pass it to others or get it from other people.

Is acanthosis nigricans dangerous?

The condition is not harmful, but it may be a sign of an underlying condition that requires treatment. If you notice unusual marks or skin shading, see your healthcare provider. Your provider or a dermatologist (skin specialist) will run some tests to determine what type of treatment you need.

Who gets acanthosis nigricans?

Anyone can develop acanthosis nigricans, including otherwise healthy people. You may be at higher risk for getting this condition if you:

• Have excess weight or obesity.
• Have a family history of AN.
• Are of Native American, African, Caribbean or Hispanic descent.
• Have darker skin.

Does acanthosis nigricans mean I have diabetes?

While AN doesn’t always mean you have diabetes or prediabetes, it can be a sign of diabetes. So talk to your healthcare provider if you notice signs of AN.

Prediabetes means you have early signs but haven’t yet developed diabetes. If you have prediabetes, your provider will talk to you about steps to take to reduce your risk of developing diabetes. And if you do have diabetes, you and your provider can discuss treatment options.

How common is acanthosis nigricans?

Acanthosis nigricans is a rare disease. Researchers don’t know how often it occurs in America. However, a study of adults with obesity found that of those who weighed double their ideal body weight, at least 50% showed signs of acanthosis nigricans.