What Causes Itching Red Lines On The Folds Of Vagina?

I have these red lines on the folds of my vagina that itch and then sting. They also bleed slightly. Preceeding this, I had the same thing with whittish, chunky, discharge which has now pretty much stopped. I'm 23, not sexually active, nor have I ever been. I think I have a yeast infection, but I'm not sure. What causes those red lines? They appear and are gone overnight, but relocate to a different area by morning...