Bumps under skin of shaft of penis

Recently i've had a constant around the upper shaft.
When the skin is stretched out, there are several bumps that are underneath the skin all around the shaft.
They are only visible when the skin is stretched out or during an erection. I'm still a virgin, and i'm not sure what it could be. I've switched to 100% cotton boxers because of a yeast infection. It seems like it's spreading, but very slowly. It only itches and is not accompanied by any pain or burn.
Any ideas what it could be?

[Nayandham]

*Recently i've had a constant itch.
Sorry, this keyboard is ..terrible.