Canker Sores

Q:  I have always been prone to getting an occasional canker sore inside my mouth. I've noticed that in the last year or so, the frequency has increased greatly. It seems as though I almost always have a sore coming or going.

I started taking the mineral supplement L-lysine and it hasn't seemed to help immensely. Are there any other suggestions you might make to try and prevent more canker sores from developing? I know stress is a factor, but what else causes these painful sores? Also, are they contagious as cold sores are? Thanks for your consideration, doctor.

A:  Canker sores occur in up to 50% of people, tend to run in families, and are more common during the winter and spring. Previously thought to be due to the herpes virus, that is not the case -- the cause is still unknown. They are not contagious like cold sores, which are caused by the herpes simplex virus. L-lysine seems to help prevent cold sores, but I haven't heard or read of any supplement that prevents canker sores.

Stress, in the form of exhaustion and lack of sleep, is probably the biggest trigger. I just saw a patient a few weeks ago who had a large, painful, ulcerated canker sore. When I asked if she was getting enough rest, she admitted to recently taking on a second job. So, my advice for prevention is go to bed early and take a nap, too, if you need it.

If the sores are so painful you can't eat, I ask the pharmacist to make a concoction of tetracycline, benadryl, mylanta, and xylocaine for the patient to swish several times a day. The sores usually heal in 7-10 days.

"Dear Doctor" is a compilation of patient questions answered by doctors from the Medical College of Wisconsin.