Rashes On The Abdomen, Pelvis, Anus And Upper Legs. Itching With Pin Prick Feeling. Not Responding To Prednisone

I am having some type of rash , that for the most part is localized to my lower abdomen, pelvis , groin , buttox, anus and upper legs. The effected areas have a mosquito bite type texture and size, but they last weeks on end. The itching starts with a series of pin prick type feelings, then intense itching. I just came off prednisone with symptoms still remaining and I have been in close contact with my wife and she has no symptoms at all ruling out skin mites. This has been going on for over two months. The effected areas do spread in their general area, but it is slow moving taking around two weeks before another spot shows up in a adjacent location. Help!