What is syndromic acanthosis nigricans (AN)?

Updated: Oct 14, 2020
  • Author: Jason H Miller, MD; Chief Editor: William D James, MD  more...
  • Print

Syndromic acanthosis nigricans is the name given to acanthosis nigricans that is associated with a syndrome. In addition to the widely recognized association of acanthosis nigricans with insulin resistance, acanthosis nigricans has been associated with numerous syndromes (see the Table in Pathophysiology). The type A syndrome and type B syndrome are special examples.

The type A syndrome also is termed the hyperandrogenemia, insulin resistance, and acanthosis nigricans syndrome (HAIR-AN syndrome). This syndrome is often familial, affecting primarily young women (especially black women). It is associated with polycystic ovaries or signs of virilization (eg, hirsutism, clitoral hypertrophy). High plasma testosterone levels are common. The lesions of acanthosis nigricans may arise during infancy and progress rapidly during puberty.

The type B syndrome generally occurs in women who have uncontrolled diabetes mellitus, ovarian hyperandrogenism, or an autoimmune disease such as systemic lupus erythematosus, scleroderma, Sjögren syndrome, or Hashimoto thyroiditis. Circulating antibodies to the insulin receptor may be present. In these patients, the lesions of acanthosis nigricans are of varying severity.

Did this answer your question?
Additional feedback? (Optional)
Thank you for your feedback!