chester is a itchy dog at times and has sensitive skin, he has enviromental allergies, he is on grain acana chicken and , before that sundancer from solid gold. If the Benadryl helps that it is not food antihistamine will not change a food allergy. I use all free and clear for laundry, no dryer sheets or anything, no fragrant plug ins, no carpet powder, vacuum a lot, and have a good air cleaner. I use vinegar and water on my laminate floors good luck |