My collie has grass allergies in the warmer months ( similar to hay fever in people), which causes any of her skin that has touched grass to go red and itchy. She will scratch and lick until she's bleeding if I don't stop her, it looks like a huge rash on her. She was fine up to the age of 3 then developed this allergy and it's never gone away, it's only early March and she's already starting to bite at her feet

. I was given Fuciderm gel to put on her originally but that can only be used short term ( a week or two) as it contains steroids and will thin the skin. Human Diprobase and other dermatological creams do the same so their out too.
After a lot of experimenting, I have finally found a way to keep it at a more bearable level for her without any steroids or the minimal I can get away with. I have a bottle of Allermyl shampoo ( made by Virbac, ask your Vet as its prescription only) which I put a bit of in a spray bottle mixed with water, so when she has been for a walk I spray her feet. I have a PawPlunger for cleaning her feet if they get muddy, so I put some in that too. Her feet have to be washed as even if she'd remained standing the whole walk, as soon as she starts scratching somewhere that part will flare up. Once her feet are clean I put a plastic cone/ lampshade on her so she can't reach to lick and leave it on for an hour or so until any itchiness has either gone or decreased. In the really warm months, say mid May - August she also gets a Piriton tablet daily which I try to give just before a walk, and if it's really severe she gets a single steroid injection from the vet to help bring it down to a more controllable level. I also have some doggy t shirts and boots for her, so that if she lies down her chest and stomach isn't directly touching the grass, same with the boots for her feet. She is fed on a high quality hypoallergenic food and the same for treats, no colours/preservatives/ unkown ingredients.
I would definitely change your dog's diet, Bakers is just about the worst food out there and could well be causing or contributing to your dog's problems. Have a look at Burns, James Wellbeloved, Wainwrights, Skinners, Arden Grange, CSJ, and Harringtons for dry kibble food and Lily's Kitchen, Applaws, Nature's Menu, Forthglade, Nature's Harvest, Collards and Simply Dog Food for wet food, many of which have grain free options. Burns, James Wellbeloved and Wainwrights also do really good wet foods. If you don't mind spending a small fortune, Orijen and Acana are two really top quality dry foods, but their freeze dried from Canada so not cheap! Have a look on Zooplus website, they have really good foods and have good offers on one or another almost constantly. If I was in you shoes, may first step would be to change the food, try the Allermyl for his paws, putting a cone on him so he can't reach to give them a chance to recover, and see how it goes from there

.