Recurring skin rash I think might be related to my RA

Hi everyone! For about a year I have experienced recurring itchy hive like rashes on my arms, hips, back, and thighs. It usually starts out in one spot and slowly then very quickly spreads causing a pink hive like looking rash that can be rather itchy. It last a month or so then clears up on its own only to come back a few months later. I finally broke down and saw the dermatologist because I was worried it could be a side effect of my RA. He did several biopsies but said the results were inconclusive so he couldn’t make an official diagnoses which was more then frustrating. I have been using a prescription strength ointment he prescribed and it does not seem to be doing much. Does anyone have any idea what this might be or what I can do to help. Any help would be greatly appreciated because this is no fun. The following is a link to my Dropbox album of the rash. Thanks in advance! https://www.dropbox.com/sh/rdmwambfijfxwa8/AACrP6bkaje2WukkYC9NrrP2a?dl=0