This is a picture of a typical case of psoriasis, with small lesions on the knuckles. Note the changes in the fingernails.
Update Date 7/23/2015
Updated by: Kevin Berman, MD, PhD, Atlanta Center for Dermatologic Disease, Atlanta, GA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.