Why my dogs skin is peeling off?

My 12 months old Dachshund had some skin allergies recently , I took him to the Vet and they couldn't find anything wrong but in about one week period he is losing his coat , The skin is dry and it is peeling of together with his coat we tried different remedies but looks like nothing helps and I already spent a lot of money for the Vet. Anybody had similar condition or knows what to do, anything helps. Thx.