OverviewFor people with actinic keratosis, cumulative skin damage is caused by repeated exposure to all ultraviolet light, including that found in sunshine. Over the years, the genetic material of cells becomes irreparably damaged and produces lesions. The lesions, like those seen here on the arm, may later become cancerous.
Review Date 8/20/2016
Updated by: David L. Swanson, MD, Vice Chair of Medical Dermatology, Associate Professor of Dermatology, Mayo Medical School, Scottsdale, AZ. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.