Large Bumps on Elbows & Knuckles

For the past few years, I've been plagued by large bumps that periodically form on my elbows and knuckles. There doesn't seem to be any rhyme or reason to their appearance, other than that they tend to flare up and become more numerous if I scratch them or worry them. When I do accidentally burst or scratch one, they leak a clear fluid.

I've tried lotions and basic skin creams, and I've also given Polysporin and a few other topical antibiotics a shot. Nothing seems to work.

The fact that they're a recurring problem and that they become more numerous when irritated seems to indicate that it's some sort of recurring viral infection, but I'm not sexually active and I've got good hygiene, so I'm not sure where I would've picked up something like herpes on my elbow. They don't look like scabies, and they're not persistent (they go away on their own after a week or two, provided I don't worry them).

I'm still in high school, and I'm somewhat hesitant to go to my parents about it, but at the same time I want to know what's going on. If it is something that can be dealt with, I want to resolve the issue once and for all, and even if it's something like herpes that can't be cured per say, I'd like to know so I can take the appropriate precautions to avoid transmitting it further.

Any help would be much appreciated.

[Oryhara]

Lost internet and accidentally double-posted, and this one has no picture as a result. Please delete this, mods.