Acanthosis Nigricans

Condition 101

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 disorders, such as diabetes, 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, however, 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.


Habif TP. Cutaneous manifestations of internal disease. In: Habif TP, ed. Clinical Dermatology. 6th ed. Philadelphia, PA: Elsevier; 2016:chap 26.

Patterson JW. Miscellaneous conditions. In: Patterson JW, ed. Weedon's Skin Pathology. 4th ed. Philadelphia, PA: Elsevier Churchill Livingstone; 2016:chap 19.

Latest Research

Latest Advance
  • Condition: Acanthosis Nigricans
  • Journal: Lasers in medical science
  • Treatment Used: Fractional 1550-NM Erbium Fiber Laser Versus 0.05% Tretinoin Cream
  • Number of Patients: 18
  • Published —
In this study, researchers compared the effectiveness of fractional 1550-nm erbium fiber laser versus 0.05% tretinoin cream for the treatment of acanthosis nigricans.
Latest Advance
  • Condition: Genu Varum in Achondroplasia
  • Journal: Medicine
  • Treatment Used: Planned Fibular Nonunion
  • Number of Patients: 27
  • Published —
This study tested the safety and efficacy of using a planned fibular nonunion through a patient's skeletal maturity (aged less than 13 years) to treat patients with genu varum in achondroplasia.
Latest Advance
  • Condition: Children with Achondroplasia
  • Journal: The New England journal of medicine
  • Treatment Used: C-Type Natriuretic Peptide Analogue Therapy
  • Number of Patients: 35
  • Published —
This study evaluated vosoritide, a biologic analogue of C-type natriuretic peptide, a potent stimulator of endochondral ossification, in the treatment of children with achondroplasia.
Latest Advance
  • Condition: Childhood Acanthosis Nigricans (AN)
  • Journal: Pediatric dermatology
  • Treatment Used: 0.1% Adapalene Gel and 0.025% Tretinoin Cream
  • Number of Patients: 0
  • Published —
This study assessed the effectiveness of topical 0.1% adapalene gel compared to 0.025% tretinoin cream in the treatment of childhood acanthosis nigricans (hyperpigmentation; AN).

Clinical Trials

Clinical Trial
  • Status: Active, not recruiting
  • Study Type: 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)