HELP!!! SKIN ISSUES ON CATs EARS & FACE

PLEASE HELP!! My cat has been from vet to vet trying to figure out what's wrong with him. He constantly scratches at his face and ears, causing hot spots and hair loss. ONLY on his face and ears A skin scrape was given and he was clean, they checked for mites and he was clean, however they still placed him on tresaderm with ivermectin. They also have changed his diet to prescription Hill's diet d/d. WHAT IS GOING ON!? Have any of you experienced anything like this what could it be help! I'm down to my last dollar and need a solution

STRESSED AND BROKEN

Have you tried many different foods? Maybe there is something in the Hill's diet that doesn't agree with him. What food was he on before Hills? Wet or dry or both?

It might be behavioural. Has anything changed recently in your house? How long as he been like this? You could try Feliway diffusers to see if that makes a difference. 

No  the hills diet was the new alternative, it seems to be helping but he is stil a little itchy. I was using instinct raw before this ever since he was a kitten. its only been a week he has been on it. I heard it takes 8-12 weeks to see a difference or change in a food allergy testing with a strict diet. nothing in the house has changed it happened about a month after we got him.