I hope you are able to get some help. Have you tried a dog food made for dogs with allergies? My winston has had (minor) skin problems and we have been able to keep it under control with
Natural Balance Vegetarian food. I also have used a deep conditioner that really help "soothe" he skin. I found a link, it was called
Davis Advanced Conditioning Treatment. Doing these two things really helped out my dog 99%. When things start to flare up, we jump right up and keep on it, and it stays at bay. Good luck, I hope you find the best cure for your dog! It's not fun.