We adopted a rescued puppy from a friend about 4 years ago and shortly thereafter, she began scratching excessively.
The first year the vet did steroid shots which helped but after several shots the vet became concerned about potential damage from this type of treatment. We then used a prescription of Atopica for almost 2 years which also seemed to help but was expensive.
We tried different foods including Canidea and Natures Valley (Dick Van Pattons Brand). Over the last year and a half, we have fed her Taste of the Wild Salmon and give her a supplement of Halo Dream Coat fish oil with every morning feeding. Results were great. No longer giving the prescription of Atopica and her skin is free of hot spots and rashes. The hair coat is soft as well.
Additionally, when she is bathed, we use Solid Gold conditioner which also seems to keep skin rash free. I have suggested Halo Dream Coat to others with dog skin issues and heard of positive responses.