What Causes Hives While Having Painful Shoulders, Arms And Hips?

I have had break outs of hives on my neck and body for 4months which are extremely itchy and don't seem to respond to antihistamines, cortisone cream or steroid cream. I've tried limiting my diet which hasn't helped. I've also had aches in my shoulders, upper arms and hips. Could this all be related? My doctor doesn't know what this could be, it is really getting me down.