cat biting skin excessively

Question
one spot under his leg is annoying to him, and he keeps cleaning it obsessively.  The spot has turned from white to pink, and he has developed another spot near his nipple.  Nos signs of ticks, fleas or worms.  Healthy coat otherwise, and he licks any wound or bacitracin ointment we apply.  What to do?

Answer
Hi Christina,
  Humm.... could be stress related, is there anything different going on at home that might make him stressed. Or could be a food allergy developing. I'm not sure. You know what.... since this is a skin question try asking the expert on this site who is a veterinary dermatologist. Take care and good luck.

Christina,
 His name is Dr. Gotthelf on this Ask the Vet. site.