what is a sore in the corner of the mouth from?
10 2 1 1 2 4. If you have a sore in the corner of your mouth, usually in both sides, you may have Angular Chelitis. This condition is not fatal, nor is it contagious, however the legions in the corner of the mouth can be very uncomfortable. The lips split and ulcerate, often if feels like paper cuts at the corners of the mouth. The legions get crusty and have a whitish hue. Often sufferers report it is brought on during a cold spell, or during the onset of winter, indicating a weakening of the immune system.