Introduction

In children, small, painful lesions inside the mouth are known as mouth ulcers or canker sores. These sores can be especially distressing for infants and upsetting for children, leading to pain during eating, drinking, and talking. They impact the oral soft tissues like the lips, gums, tongue, and inner cheeks.

Despite being often found in children, they are not spread between individuals, and the precise reason for their occurrence remains unidentified. Parents and caregivers must comprehend potential causes and effective treatment to help manage children's discomfort and facilitate healing. This article aims to examine the frequent reasons for mouth ulcers in children and offers effective treatment choices to enhance children's oral health.¹

Understanding mouth ulcers

Mouth ulcers appear inside the mouth as small, round, or oval sores with different colours, such as white, yellow, or grey, surrounded by red inflammation. They might be small or large. They often cause a painful, stinging, and burning sensation, especially when scratched by food and dental hygiene practices. Although mouth ulcers are generally harmless and self-resolve within one to two weeks, a recurrent group of ulcers might indicate certain health issues that require medical intervention.

Causes of mouth ulcers in children

Till now, there is no definite known cause for mouth ulcers; it might be according to one and not limited to the following causes: 

Trauma and injury

One of the most common causes of mouth ulcers in children. It results from accidentally biting the tongue or inside cheeks while eating and chewing solid foods, either dry or with sharp edges. In addition to the irritation that results from dental braces, the habit of babies and young children chewing on objects such as toys and pencils can also induce injuries and ulcers.²

Nutritional deficiencies

Poor nutrition and a lack of certain vitamins and minerals can cause mouth ulcers. Iron, zinc, folic acid, and vitamin B12 deficiencies are especially linked to the developing and recurring of mouth ulcers and sores. The aforementioned nutrients are essential for the preservation of the health of the mucous membranes.³

Infections

Viral and bacterial infections

The following viral and bacterial infections can cause mouth ulcers:

Fungal infections

Patients vulnerable to fungal infections typically have weakened immune systems, which can be caused by conditions such as HIV or by immunosuppressant medications. Fungal infections known to cause ulcers include histoplasmosis, blastomycosis, zygomycosis, aspergillosis, and paracoccidioidomycosis also cause ulcers and sores.¹

Allergies and sensitivities

Food allergies and sensitivities may cause mouth ulcers in children. Foods known to induce ulcers include acidic citrus fruits, tomatoes, and spices. Other children show developed ulcers with certain food additives or preservatives.⁴

Stress and hormonal change

Emotional or physical stress may trigger the development of mouth ulcers in children, especially in those facing significant school-related stress and anxiety. The changes in hormonal levels during puberty have also been linked to mouth ulcers. These lifestyle factors may also impact the immune system, and render the mucous membranes more vulnerable to ulcers.⁵

Genetic predispositions

Susceptibility to mouth ulcers may be inherited from parents to children. The likelihood of problematic ulcers is more higher in children born into families with a history of recurrent aphthous stomatitis (RAS). However, the exact genetic mechanism behind this is still unknown.⁶

Autoimmune conditions

Autoimmune conditions cause the body’s immune system to mistakenly attack its own (healthy) tissues - including the mucous membranes in the mouth, which results in mouth ulcer formation. Diseases such as Behcet's disease, Crohn’s disease, and celiac disease all have mouth ulcers as one of the manifesting symptoms, among others.⁷

Recognising symptoms of mouth ulcers

Mouth ulcers may show a variety of symptoms, according to the severity and the underlying cause of the condition. The symptoms may be presented as: 

• Pain and discomfort: the pain can range from mild to severe based on the size and place of the ulcers. The inflamed ulcer causes pain during eating, drinking, and talking
• Redness and swelling: the main symptom of an ulcer is an inflamed, red, swollen area around the ulcer
• Difficulty eating and drinking: as a result of the existing pain, the children avoid eating and drinking certain foods, like acidic or salty foods, as well as drinks. The child’s fear of pain impacts their appetite and hydration level
• Fever and swollen lymph nodes: when mouth ulcers are caused by a viral infection, the most common accompanying symptoms are fever and swollen lymph nodes in the neck

Diagnosis of mouth ulcers in children

The diagnostic procedure for mouth ulcers is fairly simple, and typically involves:⁸

• Physical examination
• Medical history review

In the majority of cases, the appearance of the ulcers and the child’s symptoms are enough to conclude the diagnosis, but in certain cases where the ulcers are recurrent and are accompanied by other manifestations that require further investigation, such as:

• Blood tests: to check for infections, autoimmune conditions, and malnutrition
• Allergy testing: to check for food sensitivity or allergic stimuli
• Biopsy: taking a small tissue sample from the ulcer to investigate more serious conditions in rare cases

Treatment options for mouth ulcers 

Mouth ulcers can be managed and treated in several ways:⁹

Home remedies and self-care

In most cases, simple home remedies and procedures can help in the relief and healing of children’s mouth ulcers. These include:

• Salt water rinses: prepare a warm saline solution by mixing salt and warm water, and gargle throughout the day to help reduce the swelling and overcome the infection
• Baking soda paste: prepare a paste from baking soda and water, then apply it to mouth ulcers. This can have a soothing effect on inflamed ulcers, reduce pain, and help balance acidity within the mouth
• Cold compresses: use ice packs on the face to help numb the pain and reduce the swelling
• Adjusting the diet: avoid acidic, spicy, or rough foods to avoid irritating ulcers

Topical treatments

The doctor may prescribe over-the-counter (OTC) topical treatment, that relieves the pain and discomfort of the ulcers:

• Corticosteroids: these are anti-inflammatory therapeutics that reduce swelling and accelerate recovery
• Antiseptics: often provided in the form of gels or mouthwashes, these medications prevent the infection from progressing, kill bacteria, keep the mouth clean, and promote healing 
• Pain relievers: these gels contain numbing agents such as benzocaine and clove extracts, and act as local anaesthetics to relieve the pain caused by ulcers

Nutritional supplements

If the mouth ulcers are thought to be caused by nutritional deficiencies, your doctor may recommend you take some of the following supplements:

• Vitamin B1: available as oral supplements, injections, or nasal sprays, and in foods like fortified cereals, meat, fish, and dairy products
• Iron: ulcers are especially common in children with iron deficiency anaemia. Iron supplements come in the form of tablets, capsules, and liquids. It is also available in foods such as red meat, beans, lentils, and spinach
• Folic acid: this repairs and supports the growth of mucous tissues in the mouth. It is available in the form of tablets and as a component of multivitamin tablets. It can also be found in foods such as green leafy vegetables, beans, and fortified cereals
• Probiotics: these supplements contain bacteria that improve your health (such as Bacillus coagulans). These “good bacteria” prevent the growth of the harmful bacteria that cause mouth ulcers in children

Medications for underlying conditions

In case they are linked to other medical conditions. The treatment of the initial condition is crucial to prevent the ulcer formation or progress. 

• Anti-inflammatory medication: usually used in the treatment of autoimmune diseases such as Behçet's or Crohn’s disease
• Antiviral medication: widely used to treat viral infections such as herpes simplex
• Gluten-free diet: especially recommended for children with celiac disease

Professional medical treatment

In the case of stubborn conditions and recurrent ulcers, patients should seek professional medical treatments; these include:

• Laser therapy: using a low-energy laser beam to clear ulcers more quickly. This also reduces pain and speeds up healing
• Prescription medications: if over-the-counter treatments are ineffective, your doctor may prescribe more potent therapeutics like corticosteroids or immunosuppressive drugs. The role of these medications is to reduce inflammation and control the immune system to heal the sores

Preventing mouth ulcers in children

There are some tips considered as preventive action to avoid mouth ulcer conditions:

• Maintain a balanced diet: attention should be paid to the kids' food content to include enough vitamins and minerals. Eating a variety of healthy foods will prevent deficiencies that cause ulcers
• Gentle (but thorough) oral care: teaching kids the right way to brush and floss their teeth gently without hurting the soft tissues inside their mouth
• Avoid trigger foods: figuring out the foods that cause ulcers in children and avoiding these types of food will reduce the ulcers' appearance
• Stress management: relieving stress through exercise, hobbies, and relaxing activities should help reduce the incidence of ulcers

When to seek medical attention

Although mouth ulcers in children are harmless and heal spontaneously within 1-2 weeks, some conditions require the attention of the parents to seek consultation and intervention from healthcare practitioners. These conditions are: 

• If the ulcers persist for more than two weeks, or continuously recur
• If the ulcers cause severe pain
• If the ulcers affect your child’s ability to talk, eat, or drink
• If the ulcers are causing systemic symptoms (or a combination of fever, swollen lymph nodes, and other symptoms)

Summary

Small, inflamed ulcers in the oral cavity, also known as canker sores, are one of the most common conditions in children. They can make eating, drinking, and even speaking uncomfortable and painful. Mouth ulcers are typically linked to bacterial or viral infections such as herpes simplex, hand-and-foot disease, and mouth diseases. However, ulcers can also be caused by deficiencies in vitamin B12, iron, and folic acid intake deficiency, food sensitivities, allergies, and minor injuries to the mouth.

As most mouth ulcers heal on their own within one or two weeks, treatments focus on maintaining childrens’ oral hygiene, avoiding the intake of salty, acidic foods, and using suitable medication for pain relief. Keeping children hydrated and addressing any underlying nutritional deficiencies are crucial to accelerating the healing process. In serious conditions, or where ulcers persist and recur, health practitioners may make arrangements for further treatment.