i have a friend who have this problem since her childhood..she do not want to see the professional for treatment or finding the cause of her problem.im very concern about her..she have a problem that her skin that is quite tanned turned much brighter that other part of her body..it is very obvious..but it only on her face not the other part of the body..the skin also does not show any kind of harm,itch,or painful..just the obvious discolouration occured..she do not want to pursue her study because of this..she is mentally distorted with this impare.hope at least for those who read this article please give me the cause or a bit information regarding this problem.