• Acanthosis Nigricans


    Acanthosis nigricans is a skin condition in which brown or black velvet-like markings appear under the arms, in the groin, or on the back of the neck. Any skin fold can be affected, including the lower lip and chin.


    Causes of acanthosis nigricans may include:
    • High insulin levels in people who are obese
    • A family history of acanthosis nigricans
    • A cancerous tumor (rarely)

    Risk Factors

    Risk factors that increases your chance of getting acanthosis nigricans include:
    • Being overweight
    • Type 2 diabetes
    • Polycystic ovary syndrome (PCOS)
    • Heredity: People of African-American descent are more likely to develop acanthosis nigricans


    If you experience any of these symptoms, do not assume it is due to acanthosis nigricans. These symptoms may be caused by other health conditions.
      Velvety-looking, dark areas on:
      • Back of the neck
      • Armpits
      • Groin
      • Elbow
      • Knees
      • Knuckles
      • Face
      • Palms


    Your doctor will ask about your symptoms and medical history. A physical exam will be done. Tests may include the following:
    • Skin biopsy
    • Blood tests
    • Imaging tests such as X-rays or endoscopy to rule out other causes
    Endoscope in stomach
    Copyright © Nucleus Medical Media, Inc.


    Treatment often involves treating the underlying cause. For example, if acanthosis nigricans is due to obesity, weight loss can improve the skin condition.
    Topical and oral retinoids and other medicines have been reported to improve appearance in some cases. They help remove excess layers of skin.


    The best way to reduce your chances of getting acanthosis nigricans is to maintain a healthy weight through diet and regular exercise.


    National Organization for Rare Diseases http://www.rarediseases.org/

    American Academy of Dermatology http://www.aad.org/for-the-public/home


    Dermatologists.ca http://www.dermatologists.ca

    Health Canada http://www.hc-sc.gc.ca


    Acanthosis nigricans. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed. Updated December 10, 2010. Accessed November 19, 2012.

    Clark N, Stulberg DL, Tovey D. Common hyperpigmentation disorders in adults: part II. Melanoma, seborrheic keratoses, acanthosis nigricans, melasma, diabetic dermopathy, tinea versicolor, and postinflammatory hyperpigmentation. Am Fam Physician. 2003 Nov 15;68(10). Available at: http://www.aafp.org/afp/20031115/1963.html . Accessed November 19, 2012.

    Goff DC, Katz AS, Feldman SR. Acanthosis nigricans in obese patients: presentations and implications for prevention of atherosclerotis vascular disease. Dermatology Online Journal . 2000;5(1). Available at: http://dermatology.cdlib.org/DOJvol6num1/original/acanthosis/katz.html . Accessed November 19, 2012.

    10/15/2010 DynaMed's Systematic Literature Surveillance http://www.ebscohost.com/dynamed/what.php : Kong AS, Williams RL, Smith M, et al. Acanthosis nigricans and diabetes risk factors: prevalence in young persons seen in southwestern US primary care practices. Ann Fam Med. 2007;5(3):202-208. Kong AS, Williams RL, Rhyne R, et al. Acanthosis Nigricans: high prevalence and association with diabetes in a practice-based research network consortium—a PRImary care Multi-Ethnic network (PRIME Net) study. J Am Board Fam Med. 2010;23(4):476-485.

    Revision Information

  • LiveWell personal health survey

    How healthy are you really? Find out – free.Learn more

    Maybe it's time to stop guessing. If you've been wanting to make some changes but just aren't sure how, the free personal health survey from LiveWell is a great place to start.

  • HeartSHAPE Spotlight

    At risk for a heart attack? Learn more

    Fight heart disease early and prevent heart attacks with HeartSHAPE® - a painless, non-invasive test that takes pictures of your heart to scan for early-stage coronary disease.

  • Calories and Energy Needs

    Calorie NeedsLearn more

    How many calories do you need to eat each day to maintain your weight and fuel your physical activity? Enter a few of your stats into this calculator to find out.

  • Ideal Body Weight

    Ideal Body WeightLearn more

    Using body mass index as a reference, this calculator determines your ideal body weight range. All you need to do is enter your height.

  • Body Mass Index

    Body Mass IndexLearn more

    This tool considers your height and weight to assess your weight status.

  • Can we help answer your questions?

    Wellmont Nurse Connection is your resource for valuable health information any time, 24 hours a day, seven days a week. Speak to a Nurse any time, day or night, at (423) 723-6877 or toll-free at 1-877-230-NURSE.