my dog has a terrible reoccurring skin rash, any herbal remedies or diagnosis?

hi. my pitt bull is almost two years old and has always had some skin problems, pretty consistently. she is constantly scratching. has had ear infections etc. i paid $800 for an allergy test and changed her food/treats and it has not gotten any better. recently they are like blisters, rashes, she is shedding much more. i feel as though she is miserable! the skin between her toes is red without hair and the vet just gives me cream(that she licks off) and benadryl. that is treating symptoms and making her sleepy but not a solution to the problem. please help!
p.s. only experienced members answer please(vet techs, breeders) i have plenty of experience with dogs and cant put my finger on this one. its not sarcoptic mange or anything like that

I have a pittie who also suffered from skin rashes and yeast ear infections. Cleared it with Dermacton and itchy Ear drops from the same company. Some pitties just seem prone to these problems.

http://www.equinat-usa.com/pages/testimonials.htm

Hope your dogs get the relief mine did from these products – she is like a different dog, much happier and less cranky. It was hard to live with her always scratching and biting herself.