Any ideas for a dog itching and pulling out her hair?

Could be very likely the food you are feeding. She could be allergic to wheat, Chicken, corn, or the by-products in the food. I would switch to a higher quality food. Either Wellness Fish & Sweet potato, Merrick's Wilderness blend or Campfire cookout. Or the Eagle Pack Holistic select anchovy food. The fish in the food has high levels of omega 3 and 6 that helps add extra nutrients to the skin and coat. Your dog will stop itching i guarentee it.