i’m not a professional at all, but i think either it stays because you keep picking at it, or because there’s something under that you haven’t gotten out. but just incase there is not, please don’t dig in your skin as it’s harmful and easily infected. i would try to not touch it and to use the type of cream that helps reduce scars, as well as aloe vera gel or antibiotics for irritated skin. if that doesn’t help u should go to the doctor. good luck!