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 obeseA family history of acanthosis nigricansA cancerous tumor—rare
Acanthosis nigricans is more common in people of African-American decent. Other factors that may increase your chance of acanthosis nigricans include:
overweightType 2 diabetesPolycystic ovary syndrome
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: Blood testsSkin biopsy if your doctor is concerned about skin cancer
Your bodily structures may need to be viewed. This can be done with: X-raysEndoscopy and colonoscopy—might be considered to screen for a rare malignancy associated with acanthosis nigricans if you are not obese or do not have diabetes
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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: Maintain a healthy weightEat a balanced dietGet regular exercise most days of the weekTalk to your doctor about your blood sugar levels
Acanthosis nigricans. EBSCO DynaMed website. Available at:
http://www.ebscohost.com/dynamed. Updated July 11, 2014. Accessed September 2, 2015.
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Last reviewed September 2015 by James Cornell, MD
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
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