Does peripheral vascular disease or mixed connective disease cause skin discolaration on any area of the body? why?

Maybe: Two very different problems. Arterial insufficiency (pad) can cause the skin to be pale, loss of hair below the mid-shin, and cool feet. Blue or black discoloration indicates threatened tissue and can result in amputation if left untreated. Any dark discoloration or non-healing wound(s) should be evaluated by a vascular specialist as soon as possible.