What is the difference between a canker sore and a cold sore?  Canker sores are also known as aphthous ulcers.  Cold sores also known as fever blisters.  Most often canker sores are located INSIDE the mouth and cold sores are located OUTSIDE of the mouth, usually on the lips or skin around the lips.  The cause of a canker sore is not known.  Canker sores ARE NOT contagious.  Cold sores are caused by herpes virus Type 1 or Type 2 and ARE contagious.  Cold sores and canker sores usually heal spontaneously with in 7-10 days.  Click here for more patient information from the American Dental Association.
The picture below is a cold sore.


The picture below is of a canker sore.

Pediatric Dental Center
Warren, MI
Dr. Shah, Dr. O’Riordan