Acanthosis Nigricans:
Teen information

Acanthosis nigricans is a skin disorder in which the skin becomes abnormally darkened and thickened. The skin is often described as "velvety" because it remains soft despite thickening. These skin changes are most often found in body creases, such as the armpits and the back of the neck.

Acanthosis nigricans is commonly seen in obese individuals and in those with some endocrine problems, such as diabetes. It is also associated with polycystic ovarian disease in women, though acanthosis nigricans can occasionally be found in people who have more serious underlying health problems or who are taking certain medications. Treatment of the underlying medical condition, including weight loss, usually resolves the skin lesions.