My cat Creamsicle has allergies, too, but we still don't know what she's allergic to. My vet seems to think that it may be environmental rather than food but he said that allergy testing is expensive and we still may not find out what's causing her itching. She was on Prednisolone but she gained a lot of weight on it so my vet switched her to Medrol and the itching and hair loss has stopped. She hasn't lost any weight, though. Her hair loss was so extreme that she lost almost all the fur off her tail and she had bald spots all over her body, poor little thing. The itching is maddening; my vet said it's like having poison ivy. I'm glad that your kitty is doing better and we hope to see pix soon.