I've put ALOT of hot sauce, hot chili peppers, basically anything really spicey, sometimes on the food I eat. My mouth is burning for at least 15 to 30 min. depending on how much hot crap I put on it. So if I had chips to say soup, it would be mostly red from the hot sauce. Then the acid reflux starts up pretty bad -doesnt help that I have acid reflux disease-. This, along with throwing up have made the corners of my mouth open a bit. It's almost unnoticable if your not up close. They used to heal, but after repeating this constantly it stopped healing.