When your cat shows symptoms of obsessive behaviour disorder it can then become a really difficult situation to cope with and as a result it can cause a lot of problems and stress to the cat and humans. Especially in cases when the disorder is caused by stress and anxiety which are difficult to figure out and any attempts to use some form of medication to help with the situation causes more stress to the cat. It becomes a vicious circle as the cat will continue lick or overgroom and bite the area to relive the stress the use of medication caused as licking and grooming is the way their use to calm themselves if they feel stressed and are in pain and therefore they will make things worse. What is normally required to stop them is usually trying to distract them or calm them so they can relax and get sufficient rest and sleep as sleep helps them boost their immune system and therefore get better sooner.
By of course the other difficult part along with treating the disorder is trying to figure out what has caused that behaviour, whether it is just stress or some other external cause such as skin irritation and reaction to products used in the house, food that they are allergic too, etc. It is often easier to pin the cause if it is just an allergic reaction but becomes more difficult if it is just stress as sometimes cats they would get upset by things which do not think or believe that they will upset them in the first place. In such cases when the cat shows the symptoms of obsessive compulsive disorder it becomes difficult to treat her as the vet will normally prescribe some form of medication to ease the symptoms but he/she won't tell you what has caused it and as result the cat will either get used to the medication and soon will have no effect or the medicine will have some unwanted and unpleasant side effects.
So what is a solution? Of course you should have your cat checked by the vet to find out possible physical causes. But obsessive licking and overgrooming parts of the body in most cases will require for a cat to have a relaxed and safe environment, to be distracted wherever possible and to be given an alternative to use instead of grooming him/herself. Figuring out what causes her to behave that way it is also important as for any treatment to work it will require first of all the removal of the cause. Therefore it is better if the human carer tries to figure out what stresses and upsets her/his pet and not to depend on the vet to tell him/her.
He/she knows better the cat and he/she will be able to figure out what in her current environment upsets her/him as not always the cause is something that might have suddenly changed. Cats that are left on their own at home for hours with nothing to do on their own can easily start show signs of obsessive behaviour because of boredom as well as cats that become over attached to their humans. Sometimes our cats will need a lot of help and understanding from us but of course they worth it and therefore we should do whatever we can to help them.