What is a Canker Sore?
A canker sore is the common term for an aphthous ulcer, a lesion inside the mouth that looks like a shallow, round, white or gray spot, often with some redness around the edge. When there are multiple ulcers, we call them “aphthae.” These lesions are painful and can make it uncomfortable to eat, drink or chew. Canker sores are not contagious.
Canker sores usually last up to 2 weeks and heal on their own.
What Causes Canker Sores?
The cause of canker sores is not fully understood. We do know the cells of the mouth seem to have an over-reactive immune response, and several internal as well as environmental factors can cause a canker sore or sores to develop:
Is a Canker Sore the Same thing as a Cold Sore?
No, they are NOT the same thing as Cold Sores, which are caused by the herpes virus and are contagious. Of note, a cold sore usually forms on the outside of the mouth, while canker sores always form on the inside of the lip or mouth.
How Do You Treat Canker Sores?
Cankers take about 1-2 weeks to heal and do not require treatment. A prescription steroid paste can help provide a barrier to the sore and soothe the area a bit, and topical anesthetics (such as lidocaine or benzocaine) can also provide some temporary relief. Using a hydrogen peroxide mouth rinse can help cleanse the sore. For severe ulcers, there are some medical procedures (such as cautery and injection) and oral medications that can help. The best ways to prevent canker sores altogether is by reducing stress, sleeping well, eating a healthy diet, and avoiding triggers you have identified in the past.
When to Seek Medical Advice