I was exposed to poison ivy and had a bad reaction

I’m looking for some answers. About a month ago, I was exposed to poison ivy and had a bad reaction. It was all over my face, arms, and breasts. My doctor prescribed oral prednisone and after my 10 day course, it was mostly gone. About 4 days later, I woke in the middle of the night with terrible itchiness. Over the next few days, my thighs, chest, neck, breasts, and the insides of my elbows developed terrible rashes. It’s been over two weeks and new spots keep cropping up on my legs and arms. Heat and stress seem to cause exceptional flares. My doctor seems to think this is an allergic atopic dermatitis unrelated to the poison ivy, but I’m not convinced. Has anyone had this happen?