Also check out whether you are allergic to anything as you can get Hives from all kinds of things ,Urticaria is Hives and there are several kind, put it into your search engine to find out more.
have they done any blood work? Should be checking lots of things--complete blood count, cpk, ast, alt, etc. Anybody mention dermatomyositis? I don't think the spelling is correct, but you can google it or talk to your dr.
Since a fever accompanies the rash flares I would suggest making an appointment with a Rheumatologist for testing for auto-immune disorders. Your problem could be part Fibro and part something else. Rashes can mean a lot of different things but for the amount of time you've had it without improvement I think it's difinetely something else entirely. Make that appointment... Good Luck and God Bless... Sheila