Reoccurring Rash

I’ve been getting this rash on my arms and recently on my thighs since February or March. There’s no pain but the itch can vary from slight to severe. I’ve been to the doctor twice already. The first time they thought it could be mites. The second time I went to the ER first because it was really bad. They gave me Benadryl, Dexamethasone, and ibuprofen. At my follow up appointment I got Vanicream and triamcinolone acetonide cream. It still took WEEKS for it to clear up. I’m going back to the doctor next week to see if they could do an allergy panel because I have no idea what it could be. I thought it could be due to work because I work around hazardous chemicals but now I’m not sure. Has anyone else experienced this? How do you clear it up quickly?? It’s just my inner thighs and the full length of my arm from back of hands to armpit.