This photograph demonstrates the hyperpigmented, brownish, velvety lesions of acanthosis nigricans. This skin condition may occur in skin folds such as the axilla (armpit - pictured here), neck, and other areas. In adults, it may be associated with hormonal problems, internal malignancy, obesity, and drugs.
Review Date 4/10/2020
Updated by: Ramin Fathi, MD, FAAD, Director, Phoenix Surgical Dermatology Group, Phoenix, AZ. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.