What Causes Rashes On Thighs And On The Vagina?

Im 13 and have some sort of rash or bites at the top of my thies and on the vaginal area, very itchy,almost burns i have no idea what it could be, its started up about two are three weeks ago and it is spreading and getting worse, it is also very scaby and i often check my nickes to notice they are wet from puss,, any ideas ?