Ouch, poor Tasha! I know how you are feeling, if you don't know the cause you can't begin to address the problem. My cat, Bobby, had dreadful allergies and had to wear an e collar for 4 months while I was trying to figure it all out. (Just removed the e coolar last week.)

Here some things I learned. First, IF it is an allergy:
- prednisone will also depress the immune system; if an antihistamine will work, that would be better. Get the dose based on weight and try Chlor Tri Meton 12 hour; Benedryl (does make them sleepy), Claritin. Straight antihistamine, no cough or cold ingredients formulas.
- warm water makes it itch more; cool water has a calming effect, but doesn't last
- if it is a food allergy, there is no reliable allergy panel. You just have to go through different foods doing trials, to figure it all out
- if it is environmental, a vet dermatologist can run the allergy panel to try and figure it all out (very expensive, about $200) Panel includes mold, mites, etc.
- you have to tackle this on 2 levels: with the antihistamine / prednisone to treat current symptoms, and with removing the food or allergen source, to cure the underlying problem.

And if it is not an allergy, it could be a few things, including:
- eosinophilic granuloma (just do a google search)
- a form of mites (her scratching spreads it to various parts of the body over time)
- a fungus ( ditto re spreading)
- other stuff

Over time, all that scratching can result in a bacterial infection on certain sites; Bobby had to have an oral antibiotic at one point during that 4 months.

My cat's appears to be food related. The common food allergies for cats are: grains; fish; chicken. He is allergic to ALL these and is currently on a prescription cat food, venison and green peas. We ARE making progress.

If a food: once you stop the food, the itchy places still take time to heal. Meantime they still itch and the pet still scratches. Which is why they tell you to do a food trial for 8 weeks. When I hit on a food which was working, I saw less inflammation and itching in a week, but it did keep on for a time after that.

So if Tasha's problem is the food, you only just stopped that less than a week back, and it is going to take time to see an improvement.

I hope this info is helpful.