My girl friend: She is 25, 160, 50kg.

She has lots of red bumps on face for several years, sometimes it happens on her back. It looks like pimples. But red, painless, itch-less, odorless, no discharge.

She didn't have it when she is a virgin. But she don't remember when she gets this trouble. 

Before physiological period or after having sex it grows more  and a little itchy.Some red bumps will grow a white spot around 3 days.Then it goes away and left a scar there. But the majority of them remain what they are about 10 days and goes away. And it looks like they are living in a period. They recured before physiological period and majority of them goes away after physiological period. 

btw: It grows more after she participates in strenuous sports.