I hope that this will be of some help to you.
I feed my gizmo science diet. It's not cheap, but well worth the price. I have noticed a huge difference in his coat, and teeth since he has been on this.
I also think that science diet makes a food just for dogs with allergies. But first things first, you have got to stop bathing her so much.. You really should try bathing her just once or twice a month, in very luke warm, almost cool water. I learned this when I worked for a vet. You don't want to use anything warmer than that because that itself is very drying to the skin.
Also I would try to use a good oatmeal shampoo on her when you do have to bathe her. As for her getting dirty between baths, I use a wet wash cloth to clean gizmo's face, and paws, booty, etc. Dogs skin is much more sensitive than human skin. And PH levels in human shampoo is too strong for dogs. I hope that this could be of some help.. Good luck!
