These red (erythematous), scaly plaques on the legs are caused by an inherited allergic condition called atopic dermatitis. Many of these areas have been scratched until they are raw and infected, with the infection triggering and perpetuating the problem. In adults, atopic dermatitis frequently involves the body creases (inside elbows, behind knees).
Kevin Berman, MD, PhD, Atlanta Center for Dermatologic Disease, Atlanta, GA. Review provided by VeriMed Healthcare Network. Also reviewed by A.D.A.M. Health Solutions, Ebix, Inc., Editorial Team: David Zieve, MD, MHA, David R. Eltz, Stephanie Slon, and Nissi Wang.