What Is The Itchy, Red Rash On The Vagina?

I have a very small rash on my inner vaginal lips, it s not thick or wide-spread, it s more like a dime-sized (if not smaller) patch. It s red and when touched it feels slightly raised, though, and where it is I have a strong, persistent itch. There s a very tiny black sore above it that hurts a bit when scratched. I ve had this for a few days and don t know what to do about it. I m a virgin, never had any sexual contact with anyone in any way, so I know for a fact that whatever is going on with my vagina has absolutely no sexual connection whatsoever.