Sorry to hear about what Kobe has been going through. Poor thing. They have no peace when they are constantly chewing or scratching. My dog used to chew on his paws and make them raw.
It sounds like he has an allergy. My dog used tho chew, get eye infections, and ear infections. In January I started doing a lot of research on dog food and found out that dogs shouldn't be eating grains. I don't give Bear any grains at all now and he doesn't have any signs of allergies anymore and also doesn't smell or have bad doggy breath either. Dogs can't process grains like humans can, although, some dogs tolerate them better than others.
I try to give Bear as much raw meat as I can. When I can't he gets EVO dog food, which is grain free. You can find it at www.naturapet.com click on EVO then where to buy. You can't purchase it on line, but you can have your vet, groomer or co-op order it for you. It cost more but you don't have to feed as much of it.
I read through all the dog foods at Petsmart and I only found one that was grain free, but it had BHA and BHT in it. I stay away from that because it has been linked to cancer.
If you want to read more about the grains and dog nutrition check out this website - www.drkarenbecker.com and click animal hostpital then on dog and cat nutrition.
I have posted several info on food allergy elimination diets b4 please read older allergy posts for advice. Also when was his thyroid levels checked last? He might need his levels adjusted. Don't be concerned about longterm use of antibiotics some dogs truly need them to live and do fine. I strongly urge you to get new bloodwork if it hasn't been done yet. Also have your vet consult a veterinary dermatologist to get a specialists insight;it can be SO helpful and save you money in the long run. The derm. that I work for encourages reg vets to call him so he can steer them in the right direction. Good Luck!