First, stop the Oatmeal shampoo immediately - every Vet Dermatologist will tell to *not* use it, ever. Try
this, instead. That is what many Vet Derm offices sell or recommend.
Buy Solid Gold's SEP (Stop Eating Poop) and use that. And elevate the litter box immediately off the floor. If she is eating cat poo, then she is eating cat litter along with it -- just imagine how many irritants are being ingested alone in that!!!
Also, get fish oil supplement formulated for
dogs such as
this, as this will moisturize the skin.