Carole Ganderton

Hi, I am new the forum and wondered if anyone had experienced their son or daughter twiddling their hair to such and extent that my son now has 2 bald patches. He has been doing this for years. He is 11 now and had recently had longer hair which has meant he is now able to do this more. Previously we have kept his hair really short. Does anyone have any tips on this or have any experiences which they want to pass on? thanks Carole