compulsive rubbing of face while asleep

My son who is a teenager has been rubbing his face a lot while asleep. He wakes up with a red irritated skin around his eyes and not only does he rub he also picks at it too (the rest of his face) which causes breaking of the skin. He says his face doesn't itch when he is awake. Just wondering if anyone has had this problem and if so, is there anything one can do to help him? I'm noticing that his self esteem is not good, please help.
I suggest taking him to a skin specialist, It could be a something to do with the temperature while he sleeps, My skin reacts badly to the heat, I get a rash, it could also he a dietary thing, My brother is gluten intolerant, so when he eats bread (or any form of wheat) he breaks out in a rash and itches. A dermatologist might be able to help :)
For information on the skin picking disorder (Dermatillomania), symptoms, causes and treatment methods, get the Complete Guide to Skin Picking Disorders.