Severe allergies

 My boy started scratching around about 4 months old. Since then he's had multiple courses of prednilisone tablets, been on fortnightly flea treatment to check for flea allergy dermatitis, he gets lumpy and bumpy and chews at his legs. Twice his ear tips turned bright purple, got hot, swelled up and scabbed over (his lynx tips fell out at this point which made me cry) and he's had hot spots on his back hocks twice. The first time was so bad we thought he'd sat in a hot frying pan.

We suspect soy as a problem so that sort of rules out Royal Canin Hypoallergenic (which also gave him diarrhea) as did the dry Z/D when I could even get him to eat it. He refuses to touch the wet. We trialed him on Hills I/D but it's full of chicken and grains and we also think he might have a problem with fish. At this point I'm wondering about the chicken but we cannot get chicken free food in Australia at all.

I've tried to put him on a raw diet a number of times so I know exactly what he's eating but that's not been successful either. Chicken made him insanely sick with diarrhea, kangaroo makes him throw up and after 2 days he refused to eat beef or lamb.

I know overseas you can get other diets made by Iams (I don't work for this company, I just googled and this is the first link that came up) here: http://www.pet360.com/product/7859/...kin-and-coat-plus-response-lb-canned-cat-food

And purina do one too but it's soy based like the RC one and not available here either: https://www.purinaveterinarydiets.com/pet-food-nutrition/feline/products/ha-hydrolyzed/

On top of all that I've read reports that animals frequently continue to react to the commercial diets anyway.

I feel very lost with it all at this point. He's okay on 1/4 tablet of prednil a day but 3 days after I stop it he's back to scratching and chewing.

For now I would keep him on the pred to control the symptoms.  I know it isn't finding the cause, many people believe that it is putting a band aid on the problem rather than fixing it but it greatly improves quality of life.  This whole thing with allergies can be very difficult to isolate.  It sounds like you are having a tough time finding something that he doesn't react to to even get started.  When you tried a raw diet was it just the protein or was it completed with some kind of premix of supplements.  I know some of the premixes do have things in them that can cause a reaction in some kitties.

Hi, sorry I didn't get back to you sooner. I appreciate the help. It really does make him a lot happier, generally within only 24 hours.

When I tried the raw diet it was just the protein source, no premix. I wanted to see how he reacted to the straight protein source initially then figured if it went well I would add premix in later.

He did okay with beef and lamb raw but he won't eat enough for a whole meal let alone enough for me to make him eat it as an exclusive diet. He's just too picky.

Honestly? I'm not sure at this point it's food. I have read that food allergies, if you continue to feed the offending food, do not respond to steroid treatment and his clearly does and quickly, despite not changing the diet.

All that is left at this point is ruling out chicken and grain but I'm not sure how to do that because there isn't a food in the whole of Australia that is fish free, soy free and chicken free!

Thank you for the help, it's very much appreciated.