Cold Sore, Canker Sore or Cancer?

What is that Sore?

Cold Sore, Canker Sore or Cancer?

Sores in and around the mouth are the source of discomfort and embarrassment for millions of Americans. Unfortunately, there’s a lot of misinformation about these lesions, so let’s have a frank discussion.

  • Canker sores and cold sores are not the same thing. Canker sores are typically small bubble-like ulcers inside the mouth – either on the inside of the lip or on the tongue. While these symmetrical sores hurt like crazy after they open up, they aren’t contagious and usually heal in 10-14 days. I have much more updated information on my website’s  Canker Sore/Cold Sore  Page.
  • Cold sores generally appear on the outside of the mouth. They look like fluid-filled blisters on the border of the lip, but will eventually open, crust over, and dry up. “Fever blisters” are caused by herpes simplex virus–type 1 (HSV-1) and are contagious. Cold sores can spread via kissing or through something as seemingly innocuous as sharing a glass of water or letting someone use your fork to sample cake. HSV-1 is closely related to genital herpes (HSV-2). Both herpes variants can be transmitted through oral sex.
  • Oral cancer lesions – in their early stage – could mimic the look of an opened canker sore anywhere inside the mouth or be a discolored lump on the edge of your lip. It might be a really sore area on your neck. The problem will not heal or go away on its own. Cancer cells may stay in a concentrated spot for a while, but will eventually spread more aggressively. It’s imperative that you get the patch of unusual tissue checked out sooner rather than later. We do oral cancer screenings as part of our general dentistry exams. It’s simple, fast and painless.


Oral cancer can be caused by a number of things. Tobacco use, whether smoked or chewed, is carcinogenic. Exposure to alcohol may be linked to oral cancer, too. Sun burns and habitual exposure to ultraviolet rays cause skin damage and may trigger cancerous growths in the sensitive lip area, as well.

Tobacco and sunburns are easy to talk about. Unfortunately, statistics now show that the human papillomavirus (HPV) – a sexually transmitted virus – is considered the fastest growing risk factor for oral cancer!  Most people don’t know this. In fact, only one out of three people is aware of this risk. Folks, if you have sexual encounters with the wrong people – those infected with HPV – you could be looking at oral cancer, genital warts or other cancers of the reproductive system. If your partner is infected with HIV, AIDS or hepatitis, well, you are playing roulette with your health and your life.

Cold sores, however, aren’t necessarily caused by physical contact like kissing. A shared water bottle or two kids trying to play a musical instrument could transfer the initial virus. So parents, think twice before you recite the “It’s nice to share” creed. Many people are infected with the cold sore virus as children, so caretakers need to stay vigilant about teaching and policing healthy behaviors.

Wearing hats and using sunscreen and lip balm with a high SPF are good habits to instill, but are especially important for those who want to keep the cold sore virus dormant. People can have the cold sore virus in their system for years before it surfaces. Sun exposure and fevers are noted triggers for HSV-1 blisters, which usually last about two weeks. Stress and even dental procedures that put strain on the lips may trigger an outbreak.

Unlike herpes, scientists do not think canker sores are viral. Environmental stress – like brushing teeth too vigorously, stressful jobs, acidic foods, or harsh toothpastes – are factors. In some cases, hormone fluctuation, immune system malfunction, nutritional problems, or even hereditary components serve as catalysts. Usually canker sores appear singly, but some patients get a dozen or more at a time. Obviously, these cases are puzzling and require more intervention because the patient can barely eat, swallow or talk.

I know this is a lot of information to absorb, but understanding the difference between canker sores, fever blisters and potentially cancerous lesions will help you make wise decisions and stay healthy. If you’re not sure what you might be dealing with, please come see me or your family physician. Early-stage oral cancer is easier to treat than cancer that has metastasized into surrounding tissue and lymph nodes. And, there are ointments that relieve canker sore discomfort. Although there’s no cure for HSV-1 fever blisters, antiviral medications may help with healing and minimize recurrence.

If you have painful mouth sores, I would be happy to take a look.

 

Tip of the Day: If you feel a cold sore threatening – tingling, burning, itching, and swelling of the lip – you can try several medications to relieve pain and speed healing. These include Zovirax, Famvir and Valtrex. They won’t prevent or cure your HPV, but they may minimize symptoms.

Best regards,

Allan Melnick, DDS

PS  Check out my website  Home Page. It is the gateway to everything you ever wanted to know about dentistry and then some.  Parts are hopelessly  boring but there is a wealth of information there for those seekers of knowledge.