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What causes mouth ulcers in children?

Most small, minor ulcers occur when there is some kind of accidental damage to the inside of the mouth. This may be the result of a cut from a sharp tooth or a piece of food, or your little one accidentally biting the inside of their cheek whilst eating. If your child has recently had a brace fitted, this can also be the trigger for a mouth ulcer.
The causes of mouth ulcers that occur on a regular basis are less well known. It is thought that there is a genetic link, with 40% of people who have recurrent mouth ulcers also reporting that other members of their family experience the same problem. Certain foods, particularly citric or acidic fruits such as lemons and strawberries, can also cause a mouth ulcer or make an existing ulcer problem worse. Other foods such as chocolate, peanuts, coffee, strawberries and cheese have also been known to cause recurrent ulcers. If your child has a lack of certain vitamins, or low iron levels, this could also be another cause. Mouth ulcers in your little one may also be a symptom of other common childhood illnesses. Recurrent mouth ulcers in your little one may also be a symptom of other childhood illnesses. Viral infections, such as chickenpox, cold sores, and hand, foot and mouth disease, may cause ulcers.
Some medications and treatments, such as ibuprofen and aspirin, can also cause mouth ulcers as a side effect.