roxy1120 (1310.1 days ago) My daughter used to get a sore similar to what you are referring to. It was the shape of a circle, maybe about the size of a quarter, and located to the side of her mouth. I think it was caused by saliva and milk, and it just irritated her skin. I put Vaseline on the little red sore, and that would usually help to heal the spot. Like you mentioned, it would clear up, then a few days later it would be back again. This continued for about 4 to 5 months then eventually cleared up on its own.