little bumps on my hands

hi, i am a 17 year old male, i master-bate atleast ones a day the next i notice little bumps on my hands, some are the size of a pin head some are the size of a pin prick, ive poped a few of them and about 2-3mins afterwards they are still leeking out with a liquid substance its really anoying because if i dont pop them they turn into huge scabs under my skin, what could these be? and what might be causing them, is it a reaction to a bit of semen on my skin ???
to could it have nothing to do with my master-bating???

please help me!

please if u have any idea what it might be, post a comment

thanks Snafu