How to Treat Sores in a Baby's Mouth?

The presence of sores in the baby's mouth causes discomfort and pain in little ones. We'll tell you what you can do when they appear.
How to Treat Sores in a Baby's Mouth?

Last update: 02 August, 2022

The discomfort caused by sores in the baby’s mouth is a cause for concern for parents.

In this article, we’ll tell you what they look like, why they appear, and what to do to help your child feel better. Keep reading!

What do sores in a baby’s mouth look like?

Sores are small inflammatory lesions that cause painful spots or ulcers in the mouth. This situation is quite common in childhood and its reasons are diverse.

When we talk about sores, we’re actually referring to canker sores. Due to the similarity to these lesions, viral and fungal infections of the mouth are also often called this way.

Canker sores appear as whitish or yellowish spots, surrounded by a reddish halo. Their size is variable and they can appear isolated or in groups.

Although they’re located anywhere on the oral mucosa, the most common sites are at the level of the cheeks, above the gums, or under the tongue. One aspect that differentiates them from viral lesions is that they’re located on the lips and soft palate.

Children with mouth sores are often irritable, have bad breath, have difficulty eating, and even sleeping. In some cases, they may have a fever and swollen glands in the neck.

These lesions usually go away on their own within 1 to 2 weeks. In any case, it’s always advisable to consult a pediatric dentist in order to determine the cause and receive the appropriate indications.

A child with a canker sore on her lower lip.

Causes of sores in a baby’s mouth

As we already mentioned, it’s quite common to call several of the painful lesions that appear in the baby’s mouth sores. Below, we’ll mention the most common causes that originate these processes.


Viral infections are the most common causes of thrush in the baby’s mouth. However, some fungal and bacterial infections can also cause them.

Among all the viruses that cause these lesions, the herpes simplex family is the most common and can trigger the following conditions:

  • Herpangina: A disease that manifests itself with multiple painful ulcers on the palate, lips, and cheeks. In addition, it can cause fever and a lot of irritability in little ones. It’s very contagious and resolves on its own after a week.
  • Herpetic gingivostomatitis: Unlike the previous one, this disease manifests itself through multiple vesicles of liquid content located in the oral mucosa. Sometimes they rupture and leave bleeding ulcers. They’re associated with fever, swollen glands, sore throat, and difficulty swallowing. Usually, little ones who suffer from it appear irritable, sore, reject food, don’t rest well, and cry frequently.

Candida albicans infections can also look like sores in a baby’s mouth. But in this case, they look like white spots with an erythematous (red) base and are located in the corners of the lips, on the palate, and on the tongue.


During chewing, tooth brushing, or playing, injuries to the oral mucosa can occur and the resulting wounds look like painful ulcers.

Other causes of sores in the baby’s mouth

Many times, sores in a baby’s mouth appear without an apparent cause. Other times, they may be associated with some of the following factors:

  • Stress or anxiety
  • Food or drug allergies
  • Systemic diseases
  • Lack of iron, vitamin B12, or folic acid

Finding out what causes these injuries helps resolve the underlying problem and improve the condition. In addition, it favors the prevention of new episodes in the future.

Treatments for sores in a baby’s mouth

In most cases, canker sores disappear spontaneously within 7 to 10 days, so curative treatments aren’t usually necessary.

Just the same, the symptoms are very annoying and interfere with certain basic activities, such as eating and resting. With this in mind, the use of anti-inflammatories or analgesics to alleviate the discomfort of the child may be necessary. Especially when the sore’s are accompanied by a fever.

In the event that the lesions are caused by bacteria or fungi, it may be necessary to resort to antibiotics or antifungals. However, this is at the discretion of the physician and the child should never be self-medicated.

For all these reasons, when sores appear in a baby’s mouth, it’s important to consult a pediatric dentist or pediatrician to detect the cause and help your little one feel better.

How to soothe a baby when they have mouth sores

As we’ve mentioned, most of the time, injuries heal on their own. Still, you can give your child relief by using the following strategies:

  • Offer a bland and cold diet: Spicy, citrus, acidic, or very hot foods exacerbate the pain. Therefore, it’s preferable to avoid them. The same with those that require a lot of chewing. On those days, it’s best to offer a cold, soft, and smooth diet.
  • Ensure sufficient hydration: The child may reject food and have no appetite due to pain. Offer plenty of fluids to prevent dehydration. Try cups or spoons if they reject the nipple on those days.
  • Avoid topical pain relievers: There are medications for local use to alleviate the discomfort caused by sores, although their use isn’t as recommended in children. They should only be used if recommended by a healthcare professional.
  • Use home remedies cautiously: There are natural alternatives to relieve pain, such as saltwater, ice, or baking soda. In any case, when dealing with the mouth of an infant, the use of these products must be done with awareness and responsibility.
Blueberry popsicles.

When to go to the doctor

If the sores in a baby’s mouth are numerous (4 or 5), last more than 2 weeks, or appear in other areas of the body (such as the eyelids or genitals) it’s important to go to the pediatrician.

Also, when the child has a fever (over 38 ° C), they’re not drinking enough fluids, or their general condition deteriorates.

Accompany the little one

The appearance of sores in a baby’s mouth is an uncomfortable situation for the child and very nerve racking for adults. Having the patience to be able to accompany your little one during the duration of this condition is essential.

In general, the lesions resolve spontaneously with the passing of time and don’t involve complications. Seeking professional help and accompanying the child with responsible and loving care will help them to better navigate this moment.

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This text is provided for informational purposes only and does not replace consultation with a professional. If in doubt, consult your specialist.