What causes pigmentation (skin staining) in venous disease?
Pigmentation of the skin around the inner, lower leg may be usually associated with extremely large varicose veins. This is more commonly seen in people who have problems with the deep veins of the leg. When valves fail, abnormally high pressures develop in the lower leg. This causes the very small blood vessels or capillaries to leak certain red blood cell components into the surrounding tissue. The red blood cells then break down to form a brown pigment or discolouration of the skin.