Hi  Skipp  it might be an allergy, a over stimulated nerve or possible
parasite

A couple question  for you

How long has this been going on?
Is the cat an outside cat?
Has there been any new stress in the house  such as  new furniture, new baby
or new other pet?
Have you changed brands in food, cat litter or has the cat been introduced
to any new objects or food morsels?
Has the cat been sleeping on anything hot or electrical?
Is the area starting to lose fur  if so does it appear to be in a circle?
Is there blood being drawn by the scratching and biting?

Sorry for all the questions   you left so need info out.

Where is the cat scratching?  My cat had "cat acne" on her chin and she
scratched at her chin all the time.  That was easily taken care of.  Give us
some more info and we'll see what we can do :)

He does not scratch just one area It will be any place on his body.He has
done this since we have had him.6 mo.he is a 4 yr old rescue cat.His skin is
clean as a whistle.I've tried vitamin E with no change.