Acanthosis nigricans is a common skin pigmentation disorder. The sign of acanthosis nigricans are usually found as dark patches of skin with a thick, velvety texture. It is usually found in body folds, such as the posterior and lateral folds of the neck, the armpits, groin, navel, forehead, and other areas.
Disease statistics: In 2002-03, 0.001% (178) of hospital consultant episodes were for acanthosis nigricans in england. 100% of hospital consultant episodes for acanthosis nigricans required hospital admission and 44% of hospital consultant episodes for acanthosis nigricans were for men and 56% were women, 3% required emergency services. 51 is the mean age of occurance, 54% occured in 15-59 year olds and 15% in over 75.