My male english bulldog also had severe allergies and he was also allergic to everthing. The allergy shots take between 7 to 9 months before you start to see results.
What I found that worked the best was weekly baths with Malaseb shampoo...if he was really itchy I would also use Resicort leave on conditioner. Both of these products are available online.
At first I would bath twice a week. This seems to provide the most relief from the allergies. Also Merlin's Dermatologist prescriped Hydroxyzine..it's like prescriptions strengh benedryl. They can have this every 6 hours and they need to take this 1/2 hour before their allergy injection.
For the folds in their face I was with a medicated acne pad for sensitive skin. This helps dry the folds out. Then I apply some Desiton ointment.
Connie