We've had this issues for years with Nimrod. She is on a hypoallergenic duck and pea diet, although I'm not 100% sure she has a food allergy.
I am shocked to hear about the weekly baths and frequent steroid injections. These are really extreme measures, and could result in drug-induced Cushings and the baths could be contributing to the problem by messing up her skin.
I do suspect the flare-ups are seasonal and dust/pollen related. When she has a flare up, the skin around her eyes poofs up, and if she scratches it, it bleeds really easily. She also gets a puffy spot on her ear. In the worst cases, she gets little mosquito-like bumps on her tummy that are extremely itchy. If we don't cone her, they will become large sores and one time she even got a yeast infection because of the irritation/immune system reaction.
After many years and several tries with treatments, we've come to the conclusion that:
This is a part of our life - we can't control it 100%, only minimize the effects
Elizabethan collars are lifesavers for flareups. She hates it, but once the 1-2 days of itchiness pass, she can go back to normal with no scabbing
Fish oil -- buy top-brand (Nordic Naturals - they are free of toxins/fillers) every day
Softpaws so she doesn't scrath up her face
Clean the house with steam mops, dust often
Don't buy or use any cleaners with perfumes. I use mostly Better Life/unscented Method products
Hypoallergenic diet - no treats.
It cant be cured. Only maintained. Let me know if you have any other questions. I have plenty of experience with this:
eye swell-up, probably dust-related:
she had an almost-deathly allergic reaction to antibiotic clavamox:
The first time we saw the belly sores -- we had no idea what cat allergies even were at this point until it got way out of control:
The dreaded cone (which actually calms her down during an itchy flare-up)
My sweet Nimrod when she does not have allergy flare-ups: