Cold Sore vs. Canker Sore

Becky RDH








Becky Larson, RDH

Cold Sore vs. Canker Sore

 In the dental field, we often have patients that are afflicted with both cold sores and canker sores.  These sores are often confused with one another.  Since medications and treatments differ with both of these types of sores, I will explain the difference between them and why it’s important to identify each correctly.

A canker sore is more like a shallow ulcer and is found inside the mouth.  Canker sores can be painful and make it difficult to eat or talk.  Most often, canker sores are caused by stress or injury to the tissues in the mouth.  Sometimes certain types of food can further trigger or irritate a canker sore.  Less often, canker sores occur due to vitamin deficiencies, gastrointestinal diseases (like Crohn’s or celiac), nutritional problems, and/or an impaired immune system.  Usually after a few days the pain from a canker sore decreases significantly.  They usually don’t require treatment and clear up within a week or two.  However, dentists can treat canker sores with a laser for immediate pain relief if needed.

A cold sore on the other hand is caused by a virus and are extremely contagious.  A cold sore is actually a group of fluid-filled blisters and occur outside the mouth, usually around the lips or nose or under the chin.   Once the blisters break, they will ooze and then crust over.  Cold sores are most contagious during the oozing stage.  Cold sores are sometimes referred to as “fever blisters” and are caused by the herpes simplex virus.   While there is no cure for cold sores, anti-viral medications can be prescribed to help promote faster healing.  Because they are extremely contagious with no cure, most dental professionals recommend rescheduling  your dental visits until after the cold sore has crusted over to prevent spreading of the virus.

As always, if you have questions or concerns with your oral health or notice persistent sores that won’t heal, please consult your dentist for recommended treatment options and/or medications.

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