My Dogs fur keeps falling out need advice thank you more info below

My dogs fur started falling out and he started to smell (yeasty) he nibbles on his own legs and body we’ve been to the vet multiple times but it hasn’t had any lasting impact he’s been on steroids which worked for a small amount of time but when they were done it just got ten times worse. We changed his diet his house his cleaning products we tried medicated shampoo from the vets but didn’t have a substantial effect. I have contacted a dermatologist and are awaiting an appointment, any advice is appreciated thank you.