I live in Florida and there are so many allergy producing plants, fleas, etc. My Brady chews on his feet and sometimes it sounds like he is biting his nails!! He doesn't chew his hair off or get sores which I am thankful for. The Vet switched his food to Royal Canin Hypo allergenic which I get from her and she said it takes about 3 months to see any results. Also make sure there isn't any gluten in the food or treats. This is what caused a lot of dogs to die last year. I get his shampoo at Pet Smart - it's made by "Gold Medal Pets", Medicated Formula, Relieves Itching, Aloe Vera Panthenol, Medicated Shampoo. " WE used to put brewers yeast powder (from health food store) in my last dog's food and the one before him we ended up having to make our own food for him which helped a lot but he didn't have the crunchy kibbles to keep his teeth clean. Hope these suggestions help.
(I'm such a night owl but 12:30 is early for me. Good Luck