I have a small bump on the skin of my areola ( very much like the bumps we get after mosquito bite), very tiny, just beside the nipple since a few years now, it is not always visible and palpable but when I repeatedly touch my areola it becomes visible and then again goes down, its very small and is of the colour of areola and if I rub on it repeatedly it becomes visible, is it normal? If so then what it is, and also there's only one . Pls reply.