OverviewThis person has a wart (verruca) that has built up a cutaneous horn which is made up of hard keratin. This does not slough-off like normal skin cells.
Review Date 10/24/2016
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.