Suggest Remedy For Itchy Skin Rashes

I have a very itchy rash on my legs, back, shoulders, chin, and upper chest. They are tiny red bumps and I have scratched so much they are scabbing and bleeding. The doctor said it is not scabies, not chicken pocks, not an allergic reaction, not hives. They gave me a steriod shot and pills but nothing works. They also gave me a vistaril shot and pills and those do not help the itching at all. She also gave me a cream to use twice a day and that does not work either. In the last couple days my legs have started bruising. I have about 7 bruises on my legs and one of them is really big and purple. I have not hit myself on anything and the bruises dont really hurt. I have not changed anything in my daily routine either.