What Is The Treatment For White Dust Like Substance On Penis Head?

There is a white dust like substance on my penis head. I see and can pull it off easiest when I have a boner (not to be rude with words, just can't spell the proper term). I masterbate usually more than once a day, I am 15 and have never had sex. (Hope to change that soon (; ). I was it once every few days, forget to do it sometimes. Hope I have supplied all the correct information.