[anonymous]

I would consult a veterinary dermatologist for the best results. Obviously, from what you have described your dog has a skin condition that needs diagnosis and treatment by a veterinary healthcare professional.

PS: You could start with the regular vet, I assume the dog has had a recent checkup, dental check and lab work to rule out medical issues. If not, that would be a good place to start.
Ask the vet about prescription food/therapeutic diet to rule out food sensitivities.