What Does Spreading Itchy Rashes On Upper Leg Be?

Since about the middle of summer a weird rash started on my upper leg right next to my pubic patch.This kinda worries me because it started as little itchy bumps but has turned into a weird kinda scarring and its spread to my other leg in the same area and i have no idea what to do about it.And i am a 17 year old male who is still a virgen.