They can appear as round or oval sores with a white, yellow, or gray center and a red border. Common locations for mouth ulcers include the insides of the cheeks, lips, tongue, gums, or the roof ...
Cold sores are painful blisters on the lips that can form unsightly crusts. They are very common and are caused by the herpes simplex virus. The medical name for facial cold sores is herpes labialis.
The herpes simplex virus that causes cold sores lies dormant in the skin around the lips waiting to pounce on any weakness be it a micro tear from chapped lips or a lowered immune system.