Some food allergies can cause mouth sores. Examples include allergies to apples, bananas, carrots, and some nuts.
Food allergies can trigger conditions such as oral allergy syndrome (OAS) and allergic contact stomatitis. These can lead to mouth sores and other symptoms.
OAS is also known as pollen-food allergy syndrome (PFAS). This is because it can happen when a person with a pollen allergy consumes fruits or vegetables related to certain trees, grasses, or weeds.
OAS can cause mouth sores, as well as symptoms such as:
- an itchy or tingling mouth
- swollen lips
- irritated gums
- a runny nose
Pollen types that commonly cause OAS include grasses, ragweed, and birch trees.
View the table below for information about foods related to grasses, ragweed, and birch trees that may cause mouth sores due to OAS.
| Pollen type | Food |
|---|---|
| Birch pollen | • almond • apple • carrot • celery • cherry • hazelnut • kiwi • peach • pear • plum • potato • pumpkin seed |
| Grass pollen | • kiwi • melon • peach • tomato |
| Ragweed pollen | • banana • cantaloupe • chamomile • cucumber • echinacea • honeydew melon • melon • sunflower seed • watermelon • zucchini |
Allergic contact stomatitis is a rare condition that can cause various symptoms inside the mouth, such as:
- sores
- blisters
- pain
- stinging
- burning
- itching
It can also affect the lips and tongue.
Symptoms can develop after coming into contact with an allergen. As well as dental materials, flavorings are a common cause of allergic contact stomatitis.
Examples of flavorings that can lead to allergic contact stomatitis include:
- balsam of Peru
- cinnamaldehyde
- eugenol
- menthol
- peppermint essential oil
These ingredients can be present in toothpaste, but they can also be in some foods. If you experience mouth sores after eating certain foods, check the ingredients to see if any of these ingredients are present.
Other flavorings may also cause allergic contact stomatitis. Bringing food labels to a doctor’s appointment may help a doctor determine the cause of your symptoms.
Contact a doctor as soon as there are concerns about mouth sores. There are many possible causes for mouth sores and other oral symptoms, so it is important to receive an accurate diagnosis.
Seek immediate medical help if symptoms of a severe allergic reaction, or anaphylaxis, develop. These can include, but are not limited to, the following:
- breathing difficulties
- facial swelling
- swelling of the mouth of throat
- hives or rashes
- itchy skin
- abdominal pain
- confusion
- speech problems
- swallowing problems
- wheezing