The FAQs about RAS

What are canker sores?

Also known as recurrent minor aphthous ulcers, recurrent aphthous stomatitis (RAS), mouth ulcers, or mouth sores, canker sores (sometimes spelled cancher sores or kanker sores) are small, round crater-like irritations, where the top layers of skin look as though they’ve been scraped away by a tiny spoon; like a miniature moon crater.

They can occur anywhere in the mouth and throat, but usually on the soft, spongy tissue.

What causes canker sores?

That’s the million dollar question. We don’t know the exact underlying cause, but we do know what triggers them most of the time. And the culprit that’s easiest to fix is in your toothpaste. Stop using a commercial toothpaste with sodium lauryl sulfate (SLS) and over time most of your canker sores will disappear. It’s as simple as that. Here are some excellent SLS-free toothpastes that will help you banish your canker sores.

Are they contagious?

The official answer is no. And although it is unlikely, the truth is, there has been no definitive cause identified for canker sores. There’s only conjecture and a few studies that point to various culprits.

If we don’t know the precise mechanism by which they occur, how can we be sure they aren’t contagious?

Can you get them on your tongue?

Yes. They can appear anywhere in the mouth. Although the most common place to get them is the inside of the cheeks (as opposed to the outside, on your face), you can also get canker sores on your tongue, the roof of your mouth, the back of your throat, the inside of your lips, your gums, under your tongue, and even on your uvula (the little hangy downy thing near your throat).

The only place you won’t ever get them, of course, is on your teeth.

Can you get a canker sore anywhere besides your mouth?

The technical term for canker sores is “recurrent aphthous stomatitis”, which literally means, repeated inflammation of the mucous tissue of the mouth [with] roundish pearl-colored specks or flakes.

So, by definition, you can’t get canker sores anywhere besides the mouth. However, if you regularly apply an irritant like SLS to other mucous membranes, you could probably develop similar sores in those areas.

How long will it take for my mouth sores to go away?

Existing mouth ulcers usually take from a few days to two weeks to go away if you do nothing – assuming you don’t make them worse with further injury or gluttonous consumption of offending foods.

You can accelerate their demise with certain topical agents: either natural treatments or chemical or drug treatments.

Getting rid of them for the long term varies with the individual, but if you completely avoid using toothpastes containing sodium lauryl sulfate (or similar agents), you will see a gradual disappearance of your canker sores over two to three months. The canker sores should disappear entirely after that.

You will also notice that you can eat foods that once gave you canker sores and not develop any.

I wouldn’t go overboard here. Going on the highly acidic Grapefruit Diet may push your system over the edge and give you a mouth sore. Moderation is the key.

Over time you will also notice that mouth injuries will simply heal without developing into a canker sore.

Does sodium lauryl sulfate cause cancer?

Apparently not. The American Cancer Society says this about SLS: “This chemical and its other compounds are known irritants, not known carcinogens.

Given the prevalence of SLS in toothpaste, if it did cause cancer there would likely be a corresponding rise in mouth cancer unrelated to tobacco, which there isn’t.

However, if SLS removes something protective from the mouth so that canker sores develop, is that a good thing? Is that even a neutral thing?

Sores and ulcers don’t occur without an underlying cause. They are the result of some sort of irritation. Irritants like alcohol and chewing tobacco have been proven to cause mouth cancer over time.

If SLS opens the door for irritations (like canker sores) to happen over and over again, that can’t be good. Why take the chance when there are excellent alternatives available?

Most people probably have nothing to worry about because they don’t develop canker sores.  In fact, only 20% of the population gets them.  But for us lucky 20%, it’s best to avoid SLS like the plague.

What is the difference between cold sores and canker sores?

Cold sores, also known as fever blisters, are caused by the herpes virus. These usually occur on the outer part of the lips or face and not inside the mouth. See canker sores herpes connection here.

Although we don’t know for sure what the specific underlying cause is, we do know that these mouth ulcers are not caused by the herpes virus. Plus, their occurrence is confined to the inside of the mouth – tongue, cheeks, gums, etc.

Is baking soda a good toothpaste replacement?

Not really. Although baking soda was used regularly many years ago as a tooth cleaning agent because it neutralizes acids and cleans well, it’s not usually recommended anymore because of its abrasiveness. You’re better off using plain water or one of several SLS free toothpastes, with a soft toothbrush.