Atopica is an immune suppressant. They give it to people so that they won't reject organs after transplant. It is however commonly used in dogs for allergies and other conditions. I don't like using it in a dog so young, and wouldn't want to unless all other options are explored. If I used it, I would have the dog on liver support.
I have had a mixed bag of specialists, many that were not helpful, though the local Derm here is great, so I understand how you might not see satisfaction. Many really are good at using high powered drugs.
I would look for a vet that is more holistic minded. Do you know any dog trainers around, or local internet forums, to look for a recommendation? To me, this stuff starts with getting the diet right. Harder to do that with a larger dog (more expensive), but there are so many good limited ingredient diets out there.
Was there anything that actually helped?