Postpartum rash

Krystal
7 weeks postpartum. About 2 weeks ago got a crazy itchy rash on my lower back and breast which has since spread to my legs and arms. Like red bumps - hive like. The itching is honestly worse than child birth. Topical steroid cream from dermatologist my OB referred me too is doing nothing. I can't take it anymore. Anyone else have this!!??