We are having similar issues here!
Have you had her ears checked for an infection or yeast? Yeast will make them itchy if there is an over abundance in their body. It could be the food or something she comes in contact with, like grass, pollen, etc. I am trying to eliminate possible allergens. So far, I have Teeka on a grain free food, coconut oil and have washed all her clothes, bedding and our blankest, etc. in hypoallergenic, scent and color free detergent. Oatmeal baths might help, too. My next step is an examine by my vet in a couple of weeks. Good Luck!