I do not know about you but there are folks have it. As far as to my own experience and mix it with the theory in science --- chin, nose and forehead are usually where the skin oils goes first and when one does not wash her/his face at least two or three times a day, the possibility is he/she can have an acne as called as chin acne and the like, especially if one is prone to dusts and all that stuffs that would goes to the open pores of our skin. And also touching your face with your hands is no good and will eventually causes an acne because you never know that your hands are clean or dirty. :-( Now if you do not treat it or have at least a first aid, it will be infected that is why it will stay in one's skin and will irritate, grows more and more --- that is called an acne. That is not good, right? So what will you do about it? For me, treating it while it is still small or fresh is advisable and not that it is already a large group of pimples! Good luck.