Canker Sores (Aphthous Ulcers)

Canker sores, also known as aphthous ulcers, are small, painful lesions that typically appear on the soft tissues inside your mouth, including the lips, cheeks, and tongue. Unlike cold sores, they do not occur on the surface of your lips and are not contagious.

Causes and triggers

While the exact cause of canker sores remains unknown, several factors may trigger their occurrence:

• Stress: Emotional stress can weaken your immune system, making you more susceptible to canker sores.
• Injury: Minor injuries from sports accidents or even aggressive tooth brushing can lead to the development of canker sores. ​
• Food Sensitivities: Certain foods, particularly acidic or spicy foods, can trigger or worsen canker sores. Common culprits include citrus fruits, tomatoes, strawberries, and certain nuts and spices.
• Nutritional Deficiencies: A lack of essential vitamins and minerals, such as vitamin B12, zinc, folic acid, and iron, can contribute to the formation of canker sores.

Duration and symptoms

Canker sores usually heal on their own within 7-10 days. During this time, you may experience a painful sore or sores inside your mouth, accompanied by a tingling or burning sensation prior to their appearance. The sores are typically round, white or yellow, and have a red edge.

Management and relief

During the healing period, the following tips can help manage pain and promote healing:

• Avoid Irritating Foods: Steer clear of spicy, acidic, or rough foods that can irritate the sore.
• Salt-Water Rinses: Rinsing your mouth with warm salt water can help soothe the pain and promote healing. Mix 1 teaspoon of salt with 1 cup of warm water and rinse your mouth several times a day. ​
• Maintain Oral Hygiene: Keeping your mouth clean can prevent secondary infections. Use a soft-bristled toothbrush and avoid toothpaste with sodium lauryl sulfate (SLS), which can irritate the sores.

When to see a dentist

While most canker sores are harmless and resolve on their own, you should consult a dentist if the sores are unusually large or persistent, lasting more than three weeks. Seek professional advice if you experience severe pain that is not alleviated by over-the-counter medications, have difficulty drinking enough fluids to stay hydrated, or experience a high fever along with the sores.