What Causes Canker Sores?

As a pediatric dental practice here in Austin, we often hear from parents who are worried about their child’s recurring mouth ulcers, better known as canker sores. These small, painful spots may look alarming, but they’re very common in children. While they usually heal on their own, the discomfort can make eating, drinking, and even smiling a challenge.

Understanding what causes canker sores—and how to treat them—can give parents peace of mind and help children recover more comfortably.

What Causes Canker Sores in Children?

Canker sores, also called aphthous ulcers, are not contagious. Instead, they can be triggered by several different factors:

1. Minor Mouth Injuries

Kids are naturally active, and sometimes small injuries inside the mouth lead to sores. Accidentally biting the cheek, brushing too hard, or irritation from braces and retainers are common culprits.

2. Diet Triggers

Certain foods may spark canker sores in sensitive children. Acidic fruits (like oranges, lemons, or tomatoes), spicy snacks, or even chocolate can cause irritation.

3. Vitamin Deficiencies

Low levels of essential vitamins such as B12, iron, and folic acid have been linked to recurring canker sores. A balanced diet often helps reduce their frequency.

4. Stress and Fatigue

School pressures, sports schedules, or changes at home can take a toll on a child’s health—including their mouth. Stress is a well-known trigger for canker sores.

5. Underlying Conditions

Although rare, frequent or unusually large canker sores may signal allergies, gastrointestinal issues, or a genetic tendency. If your child experiences ongoing problems, it’s best to discuss this with a pediatric dentist or pediatrician.

Treatment for Canker Sores in Children

The good news is that most canker sores heal naturally in 7–10 days. Still, when they’re painful, there are safe ways to ease your child’s discomfort:

• Rinses and Soothing Solutions – Saltwater or mild baking soda rinses can reduce irritation (best for older kids who can swish and spit safely).
• Topical Relief – Over-the-counter gels or protective pastes for mouth ulcers can coat the sore and reduce pain during meals.
• Pain Management – Children’s acetaminophen or ibuprofen may be helpful if the sores are severe, but always consult your dentist or pediatrician first.
• Soft Foods – Yogurt, applesauce, smoothies, and scrambled eggs are gentle options that won’t sting. Avoid acidic, spicy, or salty foods until the sore heals.
• Gentle Oral Care – Encourage brushing with a soft-bristled toothbrush to prevent additional irritation and keep the mouth clean.

In some cases, prescription rinses or medications may be recommended—especially if sores are frequent, severe, or take longer than two weeks to heal.

Helping Kids in Austin Smile Comfortably Again

At Sherwood Pediatric Dentistry, we understand how uncomfortable canker sores can be for kids. That’s why we not only treat the symptoms but also work closely with families to identify possible triggers—whether it’s diet, stress, or orthodontic appliances. With the right guidance, most children can experience fewer outbreaks and faster healing.

If your child struggles with frequent or painful canker sores, don’t wait. Schedule a visit, and together we’ll find the best way to keep their smile healthy and comfortable.

Categorised in: Pediatric Dentistry