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What Causes Canker Sores on the Tonsils?

K. Gierok
K. Gierok

Canker sores on the tonsils are most commonly caused by food allergies, sensitivities to certain medications, or bad reactions to toothpastes and other oral health products. In some instances they can also be caused by poor oral hygiene, such as not adequately brushing the teeth, particularly if the trend goes on for months at a time. Though the sores can be painful, they aren’t usually dangerous or contagious and they will usually go away on their own, often in as little as a week. Certain medicated mouthwashes can help reduce symptoms, though, and in really serious situations prescription drugs might also be required.

Canker Sore Basics

Food allergies may cause canker sores on the tonsils.
Food allergies may cause canker sores on the tonsils.

Most medical experts describe canker sores as ulcers that develop inside the mouth and throat cavity. They’re usually the most common on the inside of the lip or cheek, but they can grow on the surface of the tonsils, as well. Usually they appear as red or pinkish bumps that can feel sensitive and painful. When they develop on the inside of the cheeks, lips or gums, they're usually the result of biting or injuring the area; when they develop on the tonsils, the culprit is almost always something that was ingested or swallowed. The tonsils sit at the back of the mouth just over the throat opening and tend to be very sensitive.

Food Allergies

An allergic reaction to certian medications can manifest as canker sores in the mouth.
An allergic reaction to certian medications can manifest as canker sores in the mouth.

Food allergies are one of the most common causes of canker sores on the tonsils. Some of the most frequent triggers include strawberries, tomatoes, and other highly acidic fruits and vegetables. In addition, some types of shellfish are also linked to a high occurrence. Individuals who develop these types of canker sores might benefit from keeping track of what they eat shortly before they experience the irritation. This sort of tracking can help identify the cause of the sore so that that particular food can be avoided. Food allergy tests can also help uncover the particular food that causes the sores. Sometimes people will exhibit other symptoms of reaction, such as skin rash or difficulty breathing, but not always; in minor cases, the irritations might be one of the only noticeable symptoms.

Sensitivities to Medication

Gargling with warm salt water may help temporarily soothe a sore throat.
Gargling with warm salt water may help temporarily soothe a sore throat.

Sensitivities and allergies to certain types of medications can cause canker sores anywhere in the mouth, including the tonsils. Again, keeping track of what medications were introduced is often one of the best ways for people to help identify which particular medication caused the sore. Antibiotics are one of the most frequent culprits. Even when a person is pretty sure a medication is at the root of the problem, it’s important for him or her to consult a health care professional before trying to fix things independently. Ceasing a drug regimen before it has run its course, particularly where medications as specialized as antibiotics are concerned, can cause a range of other problems.

As a Reaction to Certain Toothpastes

Practicing good oral hygiene can help prevent canker sores on tonsils.
Practicing good oral hygiene can help prevent canker sores on tonsils.

This sort of tonsil irritation has also been linked to toothpaste allergies in some people. The allergic reaction usually happens because of a specific ingredient in the toothpaste, though what exactly that ingredient is can vary from person to person. Individuals who experience an allergic reaction to toothpaste should read the ingredient list closely. Comparing the ingredient list of an allergy-causing toothpaste with one that has not produced a reaction can help identify the canker sore causing ingredient. People who have this sort of sensitivity will often develop sores whenever they are exposed to that particular ingredient, which means that toothpaste may not be the only problem; mouthwashes or other oral care products that contain it will likely lead to similar results.

Poor Oral Hygiene

Canker sores may be caused by inadequate teeth brushing over an extended period of time.
Canker sores may be caused by inadequate teeth brushing over an extended period of time.

In some cases, canker sores on the tonsils can result from poor hygiene. Failure to brush one's teeth on a regular basis, for example, has been identified as a possible cause of canker sores, as this can lead to bacterial buildup in the mouth and bad breath. Brushing on a regular basis, using the right type of toothbrush, and applying appropriate amounts of pressure are all important in ensuring adequate dental hygiene and preventing this and other problems.

Treatment Options

Canker sores on the tonsils may cause bad breath.
Canker sores on the tonsils may cause bad breath.

Canker sores aren’t usually considered a serious medical condition, and unless they’re causing a great deal of discomfort people are usually advised to wait the situation out. Most of the time, they will go away on their own after a week or so. Sores on the tonsils are often more painful, though, and people more commonly seek treatment for these as opposed to those that occur on the lips or cheeks. Sometimes specially formulated antimicrobial mouthwashes can help reduce the swelling, and medicated gargle solutions are sometimes also prescribed. Oral medications like antibiotics might also be necessary, though these solutions are typically reserved for the most extreme cases.

Discussion Comments

anon965789

I found something called Canker Patch in the drugstore. It works wonderfully if the sore is on the inside of your lip or cheek. You put this patch on and it adheres to the sore and it has some medication on it and when you wake up it is almost healed sometimes it takes another day. You cannot put it on your tonsil, though. So I guess we just have to figure something else out for that. Also, I have been eating a lot of strawberries and my canker sores seem to be cyclical.

anon318791

Strawberries were on sale absurdly cheap at the supermarket, so I bought and ate an entire container on Monday and Tuesday. By Tuesday, I had a very bad sore throat and swollen glands that I assumed was from a developing cold. Yesterday, I was convinced that it must be strep, although I have not had a fever or any other symptoms of a cold or infection.

Today is Saturday morning and the canker sores on my tonsils are still there. I have also eaten shellfish over the past two days, so who knows if I've eaten more than one thing to cause it. I've had the same reaction to sodium lauryl sulfate -- many canker sores, and the constant brushing I was doing (thinking I didn't do a good enough job) was making it worse. No more toothpaste with that ingredient and I guess now, no more strawberries either.

anon317015

I get a canker sore on my tonsils every couple of months, but this is the first time I've heard of it being a food allergy, though. They feel like you have a sore throat, but are more of a piercing/burning than sore pain.

I am allergic to aspartame (a lot of people are, but don't know it), so chewing sugar-free gum causes a mouthful of canker sores for me and also sodium lauryl sulfate (SLS) found in toothpaste makes canker sores worse and lasts longer. I use Sensodyne toothpaste now, or Toms of Maine.

As for getting canker sores to go away faster, I've tried the oral canker sore mouthwashes. They work all right, but the best thing I've used is a gritty gel paste prescription from my doctor that "knits" your skin back together. I can't remember what it's called though. Highly recommend the gel, but it won't help with the ones on your tonsils.

To make you all feel better about having one or two canker sores at a time, I got a viral infection once and easily had over 100 canker sores cover my mouth, tonsils and throat. Couldn't eat or drink hardly anything for a week.

julies

Does anyone have any tips for some canker sore remedies that work? When I get a canker sore I usually just wait for it to go away, but would like to find something that would speed this along. Sometimes it can take weeks for a canker sore to go away and having one on the tonsils is not any fun.

This happened to me when I had a reaction to a new antibiotic I was prescribed. This is the only time I have had a reaction like this, and I stopped taking the medication right away.

golf07

I guess someone can be allergic to just about everything, but I never thought about someone having toothpaste allergies. What would be an ingredient in toothpaste that would cause a canker sore on the tonsils?

I use a natural toothpaste that is sweetened with xylitol, but use this for health purposes and not because I am allergic to any certain kind of toothpaste. I have had a canker sore on the tongue which was more annoying than anything else. I imagine that canker sores on the tonsils would be a lot worse than any other place in your mouth.

sunshined

@LisaLou-- The exact same thing happened to my dad who had been eating fresh tomatoes for years. He found out he can eat the orange tomatoes and not have any problems because they don't have as much acid.

I have never had a canker sore on my tonsils but imagine they can be pretty painful. I have had them on the inside of my cheek before and I just chew on the opposite side of my mouth until the canker sore goes away.

If they were on your tonsils, there isn't any way you could avoid them if you wanted to eat or swallow anything.

LisaLou

The first time I realized someone could get a canker sore on a tonsil was when this happened to my sister. She loves fresh tomatoes and plants a bunch of them in her garden every year. She uses these to make salsa, and she can also sit down and eat a whole plate full of them at one time.

After the tomatoes were in season for a few weeks, she developed canker sores on her tonsils because of the high acidic content of the tomatoes. Once she stopped eating them, the canker sores went away.

She was relieved that they went away, but really misses eating those fresh tomatoes. She can get by with eating a few slices, but not nearly as many as she used to eat at one time.

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    • Food allergies may cause canker sores on the tonsils.
      By: Farina3000
      Food allergies may cause canker sores on the tonsils.
    • An allergic reaction to certian medications can manifest as canker sores in the mouth.
      By: Dmitry Naumov
      An allergic reaction to certian medications can manifest as canker sores in the mouth.
    • Gargling with warm salt water may help temporarily soothe a sore throat.
      By: taka
      Gargling with warm salt water may help temporarily soothe a sore throat.
    • Practicing good oral hygiene can help prevent canker sores on tonsils.
      By: GVictoria
      Practicing good oral hygiene can help prevent canker sores on tonsils.
    • Canker sores may be caused by inadequate teeth brushing over an extended period of time.
      By: Alliance
      Canker sores may be caused by inadequate teeth brushing over an extended period of time.
    • Canker sores on the tonsils may cause bad breath.
      By: carla9
      Canker sores on the tonsils may cause bad breath.
    • Most medical experts describe canker sores as ulcers that develop inside the mouth and throat cavity.
      By: JackF
      Most medical experts describe canker sores as ulcers that develop inside the mouth and throat cavity.