Just recently, I ve developed a terribly itchy upper back. It also has become painful at times (feeling like pin pricks). When I go to scratch it, it burns & is very painful. There is no noticable marks (blisters, etc). I have not eaten anything out of the ordinary, not changed soaps, detergents, etc. I DID recently start taking an iron supplement . Could that have something to do with it? Any help would be greatly appreciated. It s making me crazy!