Definition
Acanthosis nigricans is a skin problem that results in brown or black velvet-like markings. They appear under the arms, in the groin, or on the back of the neck. It can affect any skin fold.
Risk Factors
This problem is more common in people who are Native American, Black, or Hispanic. Other things that may raise the risk are:
- Being overweight
- Having a family history of this problem
- Resistance to insulin
- Taking certain medicines that cause insulin to rise too high
Diagnosis
The doctor will ask about your symptoms and health history. A physical exam will be done. It will focus on the skin. This is often enough to make the diagnosis.
If the diagnosis is not certain, a skin biopsy may be done.
| Endoscopy |
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Treatment
The underlying cause will need to be treated. Some choices are:
- Maintaining a healthy weight through diet and exercise
- Stopping or changing medicines that may be causing insulin problems
- Medicines to improve skin appearance, such as topical and oral retinoids
- Laser therapy to improve skin appearance
Prevention
To lower the risk of this problem:
- Maintain a healthy weight through diet and exercise
- Manage insulin levels
RESOURCES
American Academy of Dermatology http://www.aad.org
NORD—National Organization for Rare Diseases http://www.rarediseases.org
CANADIAN RESOURCES
Canadian Dermatology Association http://www.dermatology.ca
Health Canada https://www.canada.ca
References
Acanthosis nigricans. EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/acanthosis-nigricans. Accessed October 29, 2020.
Phiske MM. An approach to acanthosis nigricans. Indian Dermatol Online J. 2014 Jul;5(3):239-249.
Revision Information
- Reviewer: EBSCO Medical Review Board James P. Cornell, MD
- Review Date: 09/2020
- Update Date: 04/28/2021