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Test Your Knowledge of Canker Sores

What Are Canker Sores?

Recurrent aphthous stomatitis, also known as “canker sores,” is an illness that causes small ulcers to appear in the mouth,1,2 usually inside the lips, on the cheeks, or on the tongue.2

What Causes Them?

The exact cause of canker sores is not known.1,2 There are many factors that are thought to be involved with the development of canker sores, including:

  • Immune system problems1

  • Allergies to food such as nuts, wheat products (gluten), various fruits or chocolate4

  • Stress or fatigue1

  • Viruses and bacteria1

  • Trauma to the mouth1

  • Poor nutrition2,4

  • Certain medications3

  • Systemic conditions such as Crohn’s disease1,2

  • Using toothpaste containing sodium lauryl sulfate2,3

Canker sores are not contagious and cannot be spread.2 Canker sores are usually seen in individuals before they reach age 20.3 Although severity and recurrence rates vary from patient to patient, approximately 80 percent of individuals suffer from the more minor form of this condition.3

What Are the Symptoms?

The following are the more common symptoms for the minor form of this condition. However, other conditions may cause ulcers in the mouth, so any ulcer lasting more than 10 to 14 days warrants consultation with a dental professional:3

  • Ulcers less than 1 centimeter in diameter in the mouth, usually inside the lips, on the cheeks, or on the tongue1,2,3

  • Ulcers that are covered with a gray, white or yellow layer and have a red border1,2,3

  • Ulcers that usually heal in seven to 14 days1,3 and do not cause scarring2,3

  • Ulcers that may reappear1,2

How Are Canker Sores Diagnosed?

Diagnosis is usually based on a physical exam and complete medical history.2,3   The appearance and location of the sores are helpful in identifying this condition.2,3 In addition, your dental professional may order the following tests to help confirm the diagnosis and rule out other causes for the mouth ulcers:

  • Blood tests2

  • Cultures of the ulcers2

  • Biopsy of the sore—taking a small piece of tissue and examining it microscopically2

How Are Canker Sores Treated?

The goal of treatment is to help decrease the severity of the symptoms, help with healing, and prevent recurrence.4 Treatment for minor canker sores may include:

  • Over-the-counter topical anesthetics1,4

  • Antimicrobial mouthrinses1,4

  • Avoiding hot, spicy or acidic foods1

If outbreaks are frequent and/or severe, consultation with a dental professional and perhaps other medical professionals may be in order.4 For more major cases, treatment focuses on providing relief for symptoms.3 Topical analgesics, such as benzocaine, may be used.3 Prescription drugs, such as topically delivered glucocorticosteroids, may help with disease containment.3 Keeping an ulcer diary may also help identify connections between canker sore outbreaks and diet, hygiene habits (certain toothpastes) or lifestyle (stress).4 Sharing this information with your dental professional may help you devise more effective prevention and treatment strategies.4

1 “Oral Health Topics A-Z: Common Mouth Sores.” American Dental Association. www.ada.org/public/topics/mouth_sores.asp Accessed 2008.

2 “Patient Information Sheet: Canker Sores (Recurrent Aphthous Stomatitis [RAS]). American Academy of Oral Medicine, December 31, 2007.   www.aaom.com/associations/3215/files/PatienthandoutAphthousUpdated123107.pdf Accessed 2008.

3 “Oral Mucosal Diseases in the Office Setting – Part I: Aphthous Stomatitis and Herpes Simplex Infections.” J.J. Sciubba. General Dentistry. July/August 2007, vol. 55, no. 4, pp. 347-54. www.agd.org/publications/articles/?ArtID=1858. Accessed 2008.

4 “Patient Information Sheet: Treatment of Canker Sores (Recurrent Aphthous Stomatitis [RAS]).” American Academy of Oral Medicine, December 31, 2007.  www.aaom.com/associations/3215/files/TreatmentofCankerSoresUpdated12312007.pdf Accessed 2008.

Online Medical Reviewer: Fincannon, Joy, RN, MS
Date Last Reviewed: 12/8/2008
Date Last Modified: 10/11/2008
The views represented by this article are that of the author and not of Delta Dental. This article is provided for information only. Please consult with a licensed dentist to discuss the best way for you to improve or maintain your oral health.

In all cases, specific group contract provisions, benefits, limitations and exclusions take precedence over oral health recommendations given here. We recommend that you contact your dental benefits carrier to determine the specific limitations and exclusions for your group.