One thing to think about is a psychological disorder called trichotillomania. In is more common in girls, but there are many boys that have it as well. It is most closely associate with Obsessive compulsive disorder or anxiety disorder and appears typically between ages 9-20. It is simply a nervous habit of pulling out hair on scalp, eyelashes, eyebrows and elsewhere to relive anxiety in the body. You may want to watch your son as he watches tv to see if he plays with his hair a lot.
It may be something medical, but I know a lot of people who can't figure out what is going on and Trich is not that well known.






