I've tried everything... except the vet

I feel like I'm a scratch on a broken record, but my frenchie has horrible allergies and I've done diet changes, allergy pills and the works. Even with medicated shampoos all she does is itch, and she does it to the point that she bleeds and has scabs all over her body. I can't tell if it's hives, dermatitis, fleas, but she is losing hair as well. I want to go to the vet, but I have no idea if I should take her to a regular vet or a specialist. This is my first time owning a dog, and I'm lost.