90% of allegies are environmental and 10% food so if it is food you are really lucky. So once food allergy has been completed next is it is most likely environmental so here is what you are left with
Next step is a antihistamine trial for 3 weeks with each antihistamine - benedryl,etc. The most successful i have heard of is zyrtec so ask vet about it. Also antihistamines respond better when used with omega 3 and i prefer nordic naturals omega fish oil as it is distilled and no mercury and mercury can make dogs itch and some dogs are allergic to fish oil--
Welcome to Nordic Naturals - fish oil is a natural anti-inflammatory and allergy dogs get inflamed, red and itchy.
Coconut oil is a natural antibacterial and antifungal to keep yeast and bacteria infections down in the body so this helps allergy dogs
you have to be careful with this breed though as they are prone to pancreatitis and i have dealt with that with my other yorkie and he almost died of it so any fatty acid supplement can while rare trigger the pancreas.
antihistamines many times do not work in dogs so do not be surprised in severe cases where these do not work and benedryl can either amp a dog up or sedate them as it amps my allergy dog so she is bouncing from bed to bed. It has the same affect in humans
Allergy dogs must be bathed weekly and NO OATMEAL SHAMPOOS. Oatmeal is a grain and most allergy dogs are allergic to grains so no grains in food or anything else and your dog is on a grain food with rice. The oatmeal is a grain and it is very drying and many allergy dogs are allergic to it - Mine is. If they get red spots after bath and get red after bath they are allergic to shampoo. I only use hypoallergenic natural shampoos and i really like BLUE hypoallergenic shampoo you get from petco in a blue bottle