The main sign of acanthosis nigricans is dark, thick, velvety skin in body folds and creases. It often appears in the armpits, groin and back of the neck. It develops slowly. The affected skin might be itchy, have an odor and develop skin tags.
sign acanthosis nigricans dark  thick  velvety skin body folds creases  armpits  groin back neck  develops slowly  affected skin itchy  odor develop skin tags
acanthosis nigricans