You need to work with your groomer as well. It is probably more important that the dog be well rinsed than to use a medicated shampoo with mild allergies. You may have to experiment with different brands of shampoos and conditioners to find the best for your dog. Do not let the dog get matted because that extra brushing and pulling of hair to get out the mats only further irritates the skin. Your main focus on medications will be during the worse times.
Scratching can become a habit, as can licking the feet.
Boredom can add to these behaviors so avoid leaving the dog alone for hours at a time. Keep the dog inside with air conditioning as much as possible. Now let's get to the medications. Pet owners want an instant fix and are not tolerant of vets who require return visits. Therefore vets will give that quick fix by prescribing steroids for allergies.