Canker Sores, Cold Sores, and Mouth Sores: What’s the Difference?

At C. Roger Macias Jr., DDS, we know many people have experienced some form of mouth sores or irritation. Some mouth sores are harmless and go away on their own after a few days, while others are more serious and should not be ignored. Mouth sores occur for many different reasons, but bacterial infections, viruses, or funguses often trigger them. The best way to tell the difference between a canker sore and a cold sore is that canker sores occur inside the mouth while cold sores occur on the outside the mouth.

The most common mouth sores are:

• Canker sores: A non-contagious, small, grayish ulcer with a red border, canker sores appear inside the mouth. While outside factors such as stress, fatigue, or allergies may increase the chances of developing a canker sore, most health experts believe they stem from bacteria or a virus that attacks the immune system. Canker sores typically heal within a week or two.
• Cold sores: Also called fever blisters, cold sores are contagious groups of fluid-filled blisters that often erupt around the lips and sometimes under the nose or around the chin. Cold sores are the result of the herpes simplex virus, and once infected, the virus remains in the person’s bloodstream.
• Leukoplakia: A potential warning sign of oral cancer, leukoplakia is a premalignant lesion that appears as a white patch on the inside of the mouth, tongue, or gums. The lesions, which are caused by excessive cell growth, usually afflict those who smoke tobacco. the doctor may choose to have the lesion biopsied if the outbreak appears severe.
• Oral candidiasis: Also called oral thrush or moniliasis, this condition is caused by the overgrowth of a type of yeast called candida. Common symptoms of oral candidiasis include white spots inside the mouth and on the tongue, redness or discomfort in the mouth area, sore throat, difficulty swallowing, and cracking at the corners of the mouth. It is important to visit the doctor if you have oral candidiasis. If left untreated, it may infect your bloodstream, which can be very dangerous. Healthy adults do not usually get thrush, and the condition is most often seen in infants, the elderly, patients undergoing chemotherapy, or people with AIDS or other diseases that are known to weaken the immune system.

Should you have a mouth sore that lasts a week or longer, we encourage you to give us a call and schedule an examination at our San Antonio, Texas office.