Koko had a similar problem and I spent a fortune on Vet bills until I decided to put her on a corn free diet, now she is no longer itching. I have found that this is a vets # 1 complaint ( and income producer) and the easiest way to solve the problem is by the owner doing a little study about pet allergies and make his/her own changes. It is a hit and miss proposition and you can try different
things without a vet. Throwing Steroids at the problem just mast symptoms and does not find the problem. IMO... Unfortunately most of our medical community takes the same approach, treat symptoms, to heck with the real problem.