First pregnancy, with terrible rash.

This is my first pregnancy at 24 weeks, at 19weeks I had a rash that came out and spread like crazy in a matter of days, covering my whole body. My OB had no idea what it was, him and my MD decided it was ezecmea with a secondary infection, had no choice but to use meds. It only got worse from there and had end up seeing a dermotopathologist. Had to take more meds, it finally cleared up, after finishing my meds the rash came back. It hurts, it's itches, it's miserable, and I'm losing my mind. They just keep telling me they can not do anymore until after I deliver. Has anyone else has had a problem with a rash that's not a common pregnancy rash, that just won't go away? If so I'm looking for relief. If you can please help! Thanks in advance