My staffie is 4yrs & he's been getting red blisters inbetween his toes, been told by the vet its a common problem with staffies due 2 there weight & frame, been told 2 give him Piriton as it also could be an allergy.
Any advice would be great.

I wonder if it could be Pyoderma ? the lesions or blisters usually form on the webbing between the toes, will cause lameness and the dog will lick the area, the lesions sometimes burst and release fluid, the paw will be sore to touch, if it is Pyoderma then antibiotics are the usual remedy. If the Piriton doesn't help then I'd go back to the vet and get him looked at again.