Acanthosis Nigricans

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Acanthosis Nigricans LAWRENCE E. GIBSON, MD Department of Dermatology, Mayo Clinic College of Medicine, Rochester, Minn

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canthosis nigricans is characterized by a dark, slightly raised, velvetlike eruption of the flexural areas. Most often seen in the axillae, it can also occur in the inguinal area, on the sides of the neck, in the abdominal area, and even in the mouth. There are several classifications of causation and type of lesions. The most common scenario is the development of lesions in obese persons, those with adult-onset diabetes mellitus, or those with a strong family history of diabetes mellitus. The acanthosis is thought to be representative of insulin resistance. Some cases may follow a hereditable pattern, with or without diabetes. Acanthosis nigricans may be a manifestation of internal malignancy, including solid tumors and lymphoma, or it can develop as the result of drug ingestion. The diagnosis is most often clinical, but a skin biopsy can be performed when the diagnosis is unclear. At times superficial fungal or yeast infections can imitate acanthosis nigricans. Treatment is difficult unless the underlying condition is removed. In patients with rapid onset and a negative family history, malignancy must be considered as a cause. © 2004 Mayo Foundation for Medical Education and Research

Mayo Clin Proc.

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December 2004;79(12):1571 •

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