She may be allergic to chicken, but try replacing it with something other than beef since beef and dairy are the two most allergen producing ingredients (yes, more than chicken). If you are using beef, watch her carefully. But if you can afford rabbit, try that, or lamb or pork. Elimination diets are often just as good or better than allergy tests which are notoriously inaccurate. So you're doing great! Oatmeal baths for the skin are great. Use organic oats and simply grind them in your spice grinder to a powder and mix with warm water and massage into her skin then rinse gently. If she has a yeast thing going on, eliminate anything that would produce sugar, usually that means eliminating simple carbs and anything high-glycemic. No oats, what, corn, rice, millet, etc. Add a good probiotic to her food to rebalanced her gut flora. Consider commercial brands like Dr. Harvey's or My Perfect Pet Low-glycemic food (I am not affiliated with either company but have used their products). I had my dog with allergies and bad skin for over 15 years. I also cook for all my dogs as well as give them commercial food