What is the definition of Acanthosis Nigricans?

Acanthosis nigricans (AN) is a skin disorder in which there is darker, thick, velvety skin in body folds and creases.

What are the alternative names for Acanthosis Nigricans?

AN; Skin pigment disorder - acanthosis nigricans

What are the causes for Acanthosis Nigricans?

AN can affect otherwise healthy people. It can also be related to medical problems, such as:

  • Genetic disorders, including Down syndrome and Alström syndrome
  • Hormone imbalances that occur in diabetes and obesity
  • Cancer, such as cancer of the digestive system, liver, kidney, bladder, or lymphoma
  • Some medicines, including hormones such as human growth hormone or birth control pills

What are the symptoms for Acanthosis Nigricans?

AN usually appears slowly and doesn't cause any symptoms other than skin changes.

Eventually, dark, velvety skin with very visible markings and creases appears in the armpits, groin and neck folds, and over the joints of the fingers and toes.

Sometimes, the lips, palms, soles of the feet, or other areas are affected. These symptoms are more common in people with cancer.

What are the current treatments for Acanthosis Nigricans?

No treatment is needed, as AN only causes a change in skin color. If the condition is affecting your appearance, using moisturizers containing ammonium lactate, tretinoin, or hydroquinone can help lighten the skin. Your provider may also suggest laser treatment.

It is important to treat any underlying medical problem that may be causing these skin changes. When AN is related to obesity, losing weight often improves the condition.

What is the outlook (prognosis) for Acanthosis Nigricans?

AN often disappears if the cause can be found and treated.

When should I contact a medical professional for Acanthosis Nigricans?

Call your provider if you develop areas of thick, dark, velvety skin.



Dinulos JGH. Cutaneous manifestations of internal disease. In: Dinulos JGH, ed. Habif's Clinical Dermatology. 7th ed. Philadelphia, PA: Elsevier; 2021:chap 26.

Patterson JW. Miscellaneous conditions. In: Patterson JW, ed. Weedon's Skin Pathology. 5th ed. Philadelphia, PA: Elsevier; 2021:chap 20.

  • Condition: Achondroplasia
  • Journal: Lakartidningen
  • Treatment Used: Vosoritide
  • Number of Patients: 0
  • Published —
This article discusses the new treatment, Vosoritide, for children with achondroplasia (skeletal disorder) and others with short stature.
  • Condition: Children with Achondroplasia
  • Journal: Lancet (London, England)
  • Treatment Used: Vosoritide therapy
  • Number of Patients: 121
  • Published —
The study researched the effectiveness of once-daily, subcutaneous vosoritide therapy in children with achondroplasia.
Clinical Trial
  • Status: Active, not recruiting
  • Phase: N/A
  • Intervention Type: Other, Procedure
  • Participants: 20
  • Start Date: August 1, 2019
Use Of A Novel Quantitative Tool For Evaluation of Pseudo- Acanthosis Nigricans: Acanthosis Nigricans Area And Severity Index
Clinical Trial
  • Status: Recruiting
  • Participants: 175
  • Start Date: March 31, 2019
Lifetime Impact Study for Achondroplasia (LISA)