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:
Acanthosis nigricans is more common in people of African-American decent. Other factors that may increase your chance of acanthosis nigricans include:
Symptoms include velvety-looking, dark areas anywhere on the skin.
You will be asked about your symptoms and medical history. A physical exam will be done.
Tests may include:
Your bodily structures may need to be viewed. This can be done with:
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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 medications have been reported to improve appearance in some cases. They help remove excess layers of skin.
To reduce your chances of acanthosis nigricans:
American Academy of Dermatology
NORD—National Organization for Rare Diseases
Canadian Dermatology Association
Acanthosis nigricans. EBSCO DynaMed Plus website. Available at:http://www.dynamed.com/topics/dmp~AN~T113712/Acanthosis-nigricans. Updated July 11, 2014. Accessed September 1, 2017.
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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.
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10/15/2010 DynaMed Plus Systematic Literature Surveillancehttp://www.dynamed.com/topics/dmp~AN~T113712/Acanthosis-nigricans: 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.
Last reviewed May 2018 by EBSCO Medical Review Board James Cornell, MD Last Updated: 9/2/2015