Hyperpigmented concentric rings over the tibia are secondary to prior inflammation. Residual hemosiderin from broken down red blood cells in macrophages, left behind after inlammation pigments the skin.
Update Date 5/13/2011
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, Medical Director, A.D.A.M., Inc.