I know Cyndi already bumped up your post, but I am too.
Bless your heart, you’ve really got your hands full! Just curious, has your vet checked his thyroid? Also, do you see a vet who practices traditional veterinary medicine or do you use an integrative / holistic vet? I’d visit a holistic vet; here’s a link to help you find one (it’s not all inclusive, but a good start): http://www.ahvma.org/Widgets/FindVet.html
It sounds as though, in addition to the environmental and food allergies, your little guy might have a systemic yeast infection which has evolved into a leaky gut. Someone has probably been feeding your poor little guy garbage for his entire life. I would start right away supplementing his diet with coconut oil and probiotics (you need to begin repopulating the healthy bacteria in his gut). It looks like your food allergies are: salmon, poultry mix, eggs, milk, wheat, and white potato. I’d look for something minimally processed ~ raw if possible; but if you’re choosing to feed kibble, I’d go for a grain and white potato (probably sweet potato, too) free food to switch him to as soon as possible. The first food that comes to mind is Nature’s Variety Instinct Limited Ingredient Diets.
