Sorry to hear about Denzel...I don't have many exp w/allergies, but you should look into changing his food to a premium food. Here's a link to get free samples:
http://www.yorkietalk.com/forums/yor...e-samples.html alot of the premium food companies offer limited ingredients/ grain free allergy formulas. It might not be the food he's allergic to, but it would be nice to give him a better quality food.