Acanthosis Nigricans

Synonyms

• AN

Disorder Subdivisions

• Benign Acanthosis Nigricans
• Pseudoacanthosis Nigricans
• Acanthosis Nigricans With Insulin Resistance Type A
• Acanthosis Nigricans With Insulin Resistance Type B
• Drug-induced Acanthosis Nigricans
• Hereditary Benign Acanthosis Nigricans
• Malignant Acanthosis Nigricans

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.

Resources

March of Dimes Birth Defects Foundation
1275 Mamaroneck Avenue
White Plains, NY 10605
Tel: (914)428-7100
Fax: (914)997-4763
Tel: (888)663-4637
Email: Askus@marchofdimes.com
Internet: http://www.marchofdimes.com

NIH/National Arthritis and Musculoskeletal and Skin Diseases Information Clearinghouse
1 AMS Circle
Bethesda, MD 20892-3675
USA
Tel: 3014954484
Fax: 3017186366
Tel: 8772264267
TDD: 3015652966
Email: NIAMSinfo@mail.nih.gov
Internet: http://www.niams.nih.gov

For a Complete Report

This is an abstract of a report from the National Organization for Rare Disorders, Inc. ® (NORD). A copy of the complete report can be obtained for a small fee by visiting the NORD website. The complete report contains additional information including symptoms, causes, affected population, related disorders, standard and investigational treatments (if available), and references from medical literature. For a full-text version of this topic, see http://www.rarediseases.org/search/rdblist.html

The information provided in this report is not intended for diagnostic purposes. It is provided for informational purposes only. NORD recommends that affected individuals seek the advice or counsel of their own personal physicians.

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.

For additional information and assistance about rare disorders, please contact the National Organization for Rare Disorders at P.O. Box 1968, Danbury, CT 06813-1968; phone (203) 744-0100; web site www.rarediseases.org or email orphan@rarediseases.org

Last Updated: 8/20/2007
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