Not good that he has fleas. First you need to get him a dose of Revolution or Frontline. I prefer Revolution because dogs with skin allergies which pits are very prone to do better with Revolution over Frontline. You can only get Revolution from the vet though because it is also heartworm preventive as well. If he is really badly eat up with fleas then the vet can give him a shot but that is only for extreme cases. I would check with the vet before dipping him however because if he has a skin allergy it could harm his skin or irritate it even more. After you get the fleas cleared up look at the food you are feeding. Irritated skin is a big sign of food allergies. I have found if you dog has a food allergy then the best foods are the obviously high priced natural foods (natural balance or taste of the wild). There are others but I use natural balnce sweet potato venison.