It could be scabies. Scabies is caused by little mites burrowing into your skin. The bumps they cause are usally first seen in the "creases" of your body. Between your fingers, on the back side of your knee, in your groin area, and places like that. They itch like CRAZY, expecially at night. If you have it there is a good chance you have or will give it to someone you come in contact with a lot. If you think it is scabies your doctor can give you a cream to kill them. It's not much fun. STINKY!! but it works. Good luck.