Acanthosis Nigricans

Jose A. Tschen, BA; Jaime A. Tschen, MD


Dermatology Nursing. 2007;19(4):378 



The 'Clinical Snapshot' series provides a concise examination of a clinical presentation including history, treatment, patient education, and nursing measures. Using the format here, you are invited to submit your "Clinical Snapshot' to Dermatology Nursing.


Acanthosis nigricans (AN) is a cutaneous skin disorder typically characterized by hyperpigmented, velvety, hypertrophic plaques (see Figure 1).

Figure 1.

Acanthosis nigricans is typically characterized by hyperpigmented, velvety, hypertrophic plaques.


Acanthosis nigricans can affect otherwise healthy people or can be associated with internal malignancy, endocrine abnormalities, or obesity. Some cases have a familial tendency. Acanthosis nigricans has also been reported to be associated with excessive doses of niacin, corticosteroids, and diethylstilbestrol.


Acanthosis nigricans may affect any area of the body, but is most commonly found in the axillae, nape and sides of the neck, and in the groin (see Figures 2 & 3).

Figure 2.

The axillae are common areas of presentation.

Figure 3.

The axillae are common areas of presentation.

Hallmark of the Disease

Acanthosis nigricans presents as a hypertrophic darkening of the skin most commonly in the locations noted previously. Lesions may be pruritic, but are usually asymptomatic.


Treatment of AN depends primarily upon careful exclusion of endocrine disease or internal malignancy as a cause of the disease. If no underlying medical illness is found, retinoic acid (tretinoin, Retin-AAE) may be used on the lesions.

Normal Course

Acanthosis nigricans may progress slowly, becoming darker and larger with time, or may not progress at all.

Patient Education

Informing the patient about the condition, treatment options, and its corresponding associations is important in the management. The patient should be educated about the benign and cosmetic nature of this disorder and assured that he/she has been checked for underlying malignancies and endo crine abnormalities.

Nursing Measures

A thorough clinical history and physical exam should be taken along with proper instructions of any medication prescribed.


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.