Just as a quick comment I'd take a look at your kitty's diet. It could be you need to use a more holistic, healthy food. Many of the pet foods out there have a great deal of junk in them that are hard for a cat to digest; especially if they have a delicate system.
This isn't a "food allergy", necessarily, it's simply the equivalent of a human eating big mac's three times a day every day.
try one of the human grade wet and dry foods, you may see a fairly quick change in skin and fur tone.
no itching or losing of the fur. it seems raw, ill try the root powder to see how that works. again thanks alot.
Is she itching the area or losing fur? Does the area seem scabby or flaky?
One thing you could do is give her yucca root powder supplement. This is excellent for skin and coat and it helps relieve irritation and itching. It's a bit pricy and cats don't like the taste, no matter what they tell you! But it works.
Otherwise, you might just want to have her looked at by a vet.
By the way, if the peroxide fizzes up, it doesn't necessarily mean an infection. Peroxide will do that any time it meets broken skin - a scratch or scrape or anything like that. It is simply a reaction and like I said, it doesn't necessarily mean there is an infection.