Check with your vet to see if your Pitbull can take skin supplements and which ones are suitable for his age. Also have your vet examine him to rule out any other possibilities.
Do you know what is causing them? try different foods, watch where it goes outside and monitor flare ups, best is to eleviate the cause. Soothing oatmeal baths will help discomfort.
This sort of thing might happen if your dog is exposed to bugs bites and allergic reaction. The allergies might come from the food, medicine etc. A good thing to do is to contact your vet to run some tests.
