6 doctors weighed in:

What s the difference between a cold sore and canker sore?

6 doctors weighed in
Dr. Timothy Ashley
Internal Medicine & Pediatrics
3 doctors agree

In brief: Very different

Cold sores are typically lesions on the lip that stem from infections with herpes viruses (nongenital or genital strains).
Canker sores are formally known as aphthous ulcers and occur within the mouth. It's not totally clear why, but probably immune and environmental factors are at play.

In brief: Very different

Cold sores are typically lesions on the lip that stem from infections with herpes viruses (nongenital or genital strains).
Canker sores are formally known as aphthous ulcers and occur within the mouth. It's not totally clear why, but probably immune and environmental factors are at play.
Dr. Timothy Ashley
Dr. Timothy Ashley
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Randy Burgett
General Practice
2 doctors agree

In brief: A few things

Canker sores are red, covered in a white plaque, and usually found inside the mouth on the tongue or wall of the cheek, while cold sores are red bumps that turn into blisters and are usually found outside the mouth on and around the lips.
Cold sores are exclusively caused by a herpes simplex virus while the cause of canker sores is often unknown (could be bacteria, virus, allergy, etc.).

In brief: A few things

Canker sores are red, covered in a white plaque, and usually found inside the mouth on the tongue or wall of the cheek, while cold sores are red bumps that turn into blisters and are usually found outside the mouth on and around the lips.
Cold sores are exclusively caused by a herpes simplex virus while the cause of canker sores is often unknown (could be bacteria, virus, allergy, etc.).
Randy Burgett
Randy Burgett
Answer assisted by Randy Burgett, Medical Student
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