One of our cats is an obsessive groomer. She started to lick her belly bare when we went on vacation 3 years ago, and she never stopped. The vet suggested antihistamines in case it was an allergy, but they didn’t help. Next he thought Prozac would help, but we just had a zombie who licked herself too much. We gave up on trying to fix her problem, since it wasn’t making her sick and she didn’t seem to be upset. She looks like a plucked chicken, but we still love her.
Have you thought to try hot pepper sauce on the area?