Mouth ulcers or sores can unsettle your tot and make him cranky. Find out how to ease his discomfort.


Working mum Valerie Ng was horrified when her school sent her son, Gabriel, 4, home from his childcare centre last year because he had two mouth ulcers. The teacher had called her while she was at work, to take him home because she suspected that he had Hand, Foot, Mouth Disease (HFMD).

“From what I know, Gabe had been in perfect health, and it was completely unexpected, so I panicked and rush down,” she recalls.

Gabriel did, indeed, have two mouth ulcers inside his lower lip, but he was not having a fever, nor did he have any spots on his hands. “The teacher said that he didn’t want to have his breakfast in school and didn’t want to drink water. It’s understandable because the ulcers might have been making him uncomfortable,” Ng says.

Ng took her son to the paediatrician immediately. But after an examination, it was determined that Gabriel did not have HFMD ― he had probably bitten his lip accidentally.

Ulcers can also occur when children are feeling tired or stressed, or where there is a family history of recurrent mouth ulcers.

“I was relieved because finding alternative childcare arrangements would have been a nightmare,” says Ng. She adds that she understood the school’s rationale for taking precautions because “the incidence of HFMD was also at a peak during that time”.

So, what exactly are these mouth ulcers, also known as mouth and canker sores? Dr Tan Zhen Han, a paediatrician at SBCC Baby & Child Clinic (Bukit Panjang), fills us in.

What causes mouth ulcers in toddlers and young children?
There are numerous causes of mouth ulcers in toddlers and young children, but they usually occur following some trauma to the mouth. These include mechanical trauma from accidentally biting the tongue or inside of the cheek, overchewing hard foods, or even from vigorous toothbrushing, as well as thermal injury from hot foods.

Infections are another major cause of oral ulcers in children. Common viral infections HFMD, chickenpox, and herpes gingivostomatitis (cold sore). In such cases, there may be accompanying symptoms such as fever, feelings of discomfort or rashes.

Ulcers can also occur when children are feeling tired or stressed, or where there is a family history of recurrent mouth ulcers.

Rarely, mouth ulcers can sometimes with associated with an underlying medical condition, such as vitamin deficiencies (for example, iron, vitamin B12, folate, vitamin C, zinc, and magnesium), an impaired immune system, and gastrointestinal tract disease.


How do I know if my child’s mouth ulcer is a sign of something serious and when should I bring him to a doctor?
You should bring your child to the doctor if you notice the following:

  • The ulcers are large in size (more than 1cm in diameter), when there are multiple ulcers (more than four at one time), and when there are frequent episodes (more than four episodes a year). However, as a precaution to prevent the spread of HFMD, your child’s teacher is likely to recommend that you bring your child to a doctor as long as there is more than one ulcer.
  • Your child's mouth ulcer has not healed after two weeks.
  • The ulcers appeared after starting a new medication.
  • Your child is unable to eat or drink because of the pain, and especially if there are signs of dehydration, such as dry lips or tongue, lethargy, or decreased urine output.
  • There are accompanying symptoms such as fever, rash, neck swelling or pain, bloody crusts on the lips, or red, swollen and tender gums.
  • Your child looks very sick.

What kind of medication would the doctor give?
If your child is in significant pain, a topical local anaesthetic (in the form of a wash, gels, drops or spray) is often prescribed to provide some short-term symptomatic relief. This can help improve food and fluid intake.

As a precaution to prevent the spread of HFMD, your child’s teacher is likely to recommend that you bring your child to a doctor as long as there is more than one ulcer.

Is there anything I can do to ease my child’s discomfort?
If your child is old enough to rinse or gargle with liquids, you can try warm salt water rinses.

Encourage your child’s oral intake by giving frequent small amounts of fluids to prevent dehydration ― often, cool fluids, or even frozen juice popsicles can be helpful! Using a straw to drink can also help reduce the pain by preventing the fluids from touching the ulcer.

Give your child soft, bland foods that are easy to chew and swallow. Cut foods into small pieces, or mash, blend or purée foods. Avoid giving your child salty or spicy foods, citrus fruits, nuts, tomatoes and chocolates, as they can often make the ulcers more painful. Always remember that fluid intake is more important than eating any solids.

How long will it usually take to heal?
Oral ulcers usually heal within one to two weeks.

How can I prevent mouth ulcers? Should he eat more of certain foods or avoid some?
Although it can be very difficult to prevent mouth ulcers in children, good oral hygiene is certainly important. Make sure that your child uses a toothbrush with soft bristles, and brushes gently. Do take them to visit the dentist regularly.

If your child has a habit of thumb-sucking, remember to cut his nails regularly. For younger children, be wary of toys, or objects with sharp edges that your child may put into his mouth ― though we all know it can be very hard to stop them!

Similarly, good hand hygiene is equally important ― teach your child to wash his hands regularly at home and in school ― this can help reduce the spread of infections such as HFMD.

Dr Tan Zhen Han is a paediatrician at SBCC Baby & Child Clinic (Bukit Panjang).

Photos: iStock

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