Skin burning like bad abrasion

For years I have had this terrible burning patch that can start anywhere on my right leg usually. (Although a few times I have had it on my left leg) Almost always from the knee down. The patch is usually several inches wide. It will last about a week but during that time is migrates slowly upward or downward. Say if it starts around my ankle by the end of the week it has moved up my leg in the same size patch. It starts out like a sore area but within a day it turns to the burning pain. Like you want to rub it like a itch but it is hard to call it an itch. It hurts to touch and even wear clothing. This can happen once or twice a month and then disappear for months. For the first time it started on the outer right side of my shoulder blade. This is the 3rd day and it has moved to my under arm and upper outside of my right arm. For some reason it seems more painful here. It also feels deeper than just the skin like trying to touch a very bad bruise. Wondering if anyone has been told this could have anything to do with auto-immune disorders. I have had several other auto-immune disorders. (Raynaud's Syndrome, Granuloma  annulare, SLK of the eye, filamentary keratitis of the eye) I know it must not be life threatening but I am trying to tie all these auto-immune things together. I have seen a neurologist and ask several other doctors all to say "Oh, that is interesting - I've never heard of that before, I don't know." I've been told all these disorders can finally lead to Lupus or even Leukemia. If I could find out maybe I could do something about that. Thanks for any answers! LSK