it is not a internal problem, if that were the case doctors would now this, listening to him is like listening to sylvia brown. Ask yourself why the only areas affected on us is the same in every case, top middle of upper lip and bottom lower lip. Really, stick out your tongue and see the areas of your lip it touches, these areas are the same areas the tongie touches, it is from excessive licking of the lips which damaged the skin tissue. Mayvbe you didnt even realize it when you were licking them at a point in your life. People do many things that they are not aware of.................