Acanthosis Nigricans
National Organization for Rare Disorders, Inc.
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General Discussion
Acanthosis nigricans (AN) is a skin condition characterized by abnormally increased coloration (hyperpigmentation) and "velvety" thickening (hyperkeratosis) of the skin, particularly of skin fold regions, such as of the neck and groin and under the arms (axillae). Various benign (non-cancerous) forms of AN have been identified in which the disorder may be inherited as a primary condition or associated with various underlying syndromes, an excess accumulation of body fat (obesity), or the use of certain medications (i.e., drug-induced AN). In other instances, AN may occur in association with an underlying cancerous tumor (i.e., malignant AN).
Experts suggest that AN, may be a skin manifestation of insulin resistance, which is a condition characterized by impaired biological responses to insulin. Insulin, a hormone produced by the pancreas, regulates blood glucose levels by promoting the movement of glucose into cells for energy production or into the liver and fat cells for energy storage. (Glucose is a simple sugar that is the body's primary source of energy for cell metabolism.) Some clinicians suggest that insulin resistance causes a build-up of the hormone in the blood and then it finds its way into skin cells. Insulin resistance may be associated with various disorders, including obesity and non-insulin-dependent (type II) diabetes mellitus. In individuals with type II diabetes mellitus, the pancreas produces insulin but the body becomes resistant to its effects, leading to insufficient absorption of glucose and abnormally increased glucose levels in the blood (hyperglycemia) and urine. As a result, there may be a gradual onset of certain symptoms, including excessive urination (polyuria) and increased thirst (polydipsia), and the development of particular complications without appropriate treatment.
Supporting Organizations
Genetic and Rare Diseases (GARD) Information Center
- PO Box 8126
- Gaithersburg, MD 20898-8126
- Tel: (301)251-4925
- Fax: (301)251-4911
- Tel: (888)205-2311
- Website: http://rarediseases.info.nih.gov/GARD/
March of Dimes
- 1275 Mamaroneck Avenue
- White Plains, NY 10605
- Tel: (914)997-4488
- Fax: (914)997-4763
- Email: AskUs@marchofdimes.org or preguntas@nacersano.org
- Website: http://www.marchofdimes.org and nacersano.org
NIH/National Institute of Arthritis and Musculoskeletal and Skin Diseases
- Information Clearinghouse
- One AMS Circle
- Bethesda, MD 20892-3675
- USA
- Tel: (301)495-4484
- Fax: (301)718-6366
- Tel: (877)226-4267
- Email: NIAMSinfo@mail.nih.gov
- Website: http://www.niams.nih.gov/
For a Complete Report
This is an abstract of a report from the National Organization for Rare Disorders (NORD). For a full-text version of this report, go to www.rarediseases.org and click on Rare Disease Database under "Rare Disease Information".
The information provided in this report is not intended for diagnostic purposes. It is provided for informational purposes only.
It is possible that the title of this topic is not the name you selected. Please check the Synonyms listing to find the alternate name(s) and Disorder Subdivision(s) covered by this report.
This disease entry is based upon medical information available through the date at the end of the topic. Since NORD's resources are limited, it is not possible to keep every entry in the Rare Disease Database completely current and accurate. Please check with the agencies listed in the Resources section for the most current information about this disorder.
Last Updated: 8/20/2007
Copyright 2007 National Organization for Rare Disorders, Inc.
