I am glad that you found a vet that can help you with this, it sounds very encouraging. I also hold out hope not using a processed diet.
I have a new small breed pup here (10 1/2 months old) that was having some real "itch" issues, so I ran a few tests that have been very helpful here. If you're interested, here are what the results look like:
Through the Spectrum Labs test on my last dog, I found out he was allergic to cotton of all things - I would have mever suspected.
Good luck with this new phase, I am hopeful for you!