During my research, I have found that the actual percentage of dogs that have real food allergies is small! The majority of the displayed "allergy symptoms" is just the way the dog is trying to get the crap out of his body!
Do you want to get your dog to stop itching (assuming it is not from fleas/insect bites)? The best way is to start feeding him homemade, healthy dog food. If you don't think you can do that, then at least try to buy an all-natural dog food.
Start feeding your dog healthy, nutritious food and you'll finally see your dog stop itching. I did. Now it doesn't happen overnight - it takes a few weeks, but you'll notice the gradual decrease of itching and scratching, until it finally stops.
Other benefits to feeding your dog homemade dog food include reduced gas, smaller stools, less eye discharge, softer coat, and no more doggie breath! I'm not just quoting something here - this is what I've actually experienced with both of my dogs - in about 2 months of homemade dog food. There are more stated benefits that my dogs never had so I can't verify - like: fewer ear infections, less diarrhea, less nasal discharge, no more "dog smell".
Want to find out more about homemade, healthy dog food? Want to finally, once and for all, learn how to get your dog to stop itching? Try this e-book, Dog Food Dangers, and all of your questions will be answered.