Acanthosis nigricans

Request an Appointment
Print

Overview

Acanthosis nigricans is a condition that causes areas of dark, thick velvety skin in body folds and creases. It typically affects the armpits, groin and neck.

Acanthosis nigricans (ak-an-THOE-sis NIE-grih-kuns) tends to affect people with obesity. Rarely, the skin condition can be a sign of cancer in an internal organ, such as the stomach or liver.

Treating the cause of acanthosis nigricans might restore the usual color and texture of the skin.

Symptoms

The main sign of acanthosis nigricans is dark, thick, velvety skin in body folds and creases. It often appears in the armpits, groin and back of the neck. It develops slowly. The affected skin might be itchy, have an odor and develop skin tags.

When to see a doctor

Consult your health care provider if you notice changes in your skin — especially if the changes are sudden. You may have an underlying condition that needs treatment.

Request an appointment

From Mayo Clinic to your inbox

Sign up for free and stay up to date on research advancements, health tips, current health topics, and expertise on managing health. Click here for an email preview.

To provide you with the most relevant and helpful information, and understand which information is beneficial, we may combine your email and website usage information with other information we have about you. If you are a Mayo Clinic patient, this could include protected health information. If we combine this information with your protected health information, we will treat all of that information as protected health information and will only use or disclose that information as set forth in our notice of privacy practices. You may opt-out of email communications at any time by clicking on the unsubscribe link in the e-mail.

Causes

Acanthosis nigricans might be related to:

  • Insulin resistance. Most people who have acanthosis nigricans have also become resistant to insulin. Insulin is a hormone secreted by the pancreas that allows the body to process sugar. Insulin resistance is what leads to type 2 diabetes. Insulin resistance is also related to polycystic ovarian syndrome and might be a factor in why acanthosis nigricans develops.
  • Certain drugs and supplements. High-dose niacin, birth control pills, prednisone and other corticosteroids may cause acanthosis nigricans.
  • Cancer. Some types of cancer cause acanthosis nigricans. These include lymphoma and cancers of the stomach, colon and liver.

Risk factors

The risk of acanthosis nigricans is higher in people who have obesity. The risk is also higher in people with a family history of the condition, especially in families where obesity and type 2 diabetes are also common.

Complications

People who have acanthosis nigricans are much more likely to develop type 2 diabetes.

By Mayo Clinic Staff
Request an appointment
Diagnosis & treatment
June 02, 2022
Print
  1. AskMayoExpert. Polycystic ovary syndrome. Mayo Clinic; 2021.
  2. Kang S, et al., eds. Hypermelanoses. In: Fitzpatrick's Dermatology. 9th ed. McGraw Hill; 2019. https://accessmedicine.mhmedical.com. Accessed April 4, 2022.
  3. Niacinamide. Natural Medicines. https://naturalmedicines.therapeuticresearch.com. Accessed April 4, 2022.
  4. Gibson LE. Acanthosis nigricans. Mayo Clinic Proceedings. 2004; doi:10.4065/79.12.1571.
  5. Dinulos JGH. Cutaneous manifestations of internal disease. In: Habif's Clinical Dermatology. 7th ed. Elsevier; 2021. https://www.clinicalkey.com. Accessed April 4, 2022.
  6. Thoenes MM. Acanthosis nigricans: An opportunity for intervention. Journal for Nurse Practitioners. 2012; doi:10.1016/j.nurpra.2012.04.010.
  7. Kang S, et al., eds. Diabetes and other endocrine diseases. In: Fitzpatrick's Dermatology. 9th ed. McGraw Hill; 2019. https://accessmedicine.mhmedical.com. Accessed April 4, 2022.

Related

Associated Procedures

Products & Services

Acanthosis nigricans