Acral Acanthosis Nigricans also known as Acral Acanthotic Anomaly (AAA) - Acral acanthosis nigricans is a common and thus important variant of Acanthosis nigricans

Acanthosis nigricans

Acanthosis nigricans is a brown to black, poorly defined, velvety hyperpigmentation of the skin. It is usually found in body folds, such as the posterior and lateral folds of the neck, the axilla, groin, umbilicus, forehead, and other areas.-Causes:...

. Classical acanthosis nigricans is characterized by hyperpigmented, velvety thickening of the skin typically on the nape and sides of the neck and in the axillae and groin . It is also known as acral acanthotic anomaly, the two terms being synonymous. The former emphasizes that it is a type of acanthosis nigricans, the latter its uniqueness. It was discovered by internationally renowned dermatologist Robert A. Schwartz

Robert A. Schwartz

Robert A. Schwartz is an American physician and the discoverer of the Schwartz-Burgess Syndrome. He is a professor and the Head of the Department of Dermatology at New Jersey Medical School...

. Its original description in 1981 observed it as a disorder seen relatively commonly as velvety hyperpigmented plaques in dark complexioned individuals. It is often particularly prominent over the elbows, knees, knuckles and dorsal surfaces of the feet in otherwise healthy individuals with axillae and other intertriginous regions appearing normal.

Etiology

The etiology of acral acanthosis nigricans is unknown. Its presence does not suggest the necessary of an evaluation for the presence of internal malignancy.