Hi. I'm Dr. Gotthelf. I have been a skin and ear vet for 35 years and I would like to use my experience to help you with your pet's medical problem.
If there is any irritation or itching of the sheath of the penis, then a cortisone creme or a shot may be needed to get him to stop licking it. The cortisone will take down the itching and then if he leaves it alone, the skin will get a chance to heal.