Does autoimmune disease run in the family?
You could look at Raynaud's syndrome. My daughter has this. When you press her legs, it takes quite a while for the colour to bounce back.
...Julia
Look up Reflex Sympathetic Dystrophy, and see if that has info that matches. Otherwise, Raynauds is similar.
There's a website call RSD.org. They may have info that helps.