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 that increases your chance of getting acanthosis nigricans include:
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
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
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.
- Reviewer: Brian Randall, MD
- Review Date: 03/2013 -
- Update Date: 00/31/2013 -