oral health center

Are Canker Sores a Virus?

Canker sores are not caused by viruses, and their cause is not known. Possible causes and triggers may include mouth injuries (biting, vigorous tooth brushing, friction from braces), stress, sodium lauryl sulfate (SLS), nutritional deficiencies, hormonal changes, immune system problems, genetics, sensitivity to certain foods, certain medical conditions, medications, and others.
Canker sores are not caused by viruses, and their cause is not known. Possible causes and triggers may include mouth injuries (biting, vigorous tooth brushing, friction from braces), stress, sodium lauryl sulfate (SLS), nutritional deficiencies, hormonal changes, immune system problems, genetics, sensitivity to certain foods, certain medical conditions, medications, and others.

Canker sores (also called aphthous ulcers or aphthous stomatitis) are commonly found, small and painful ulcers that form inside the mouth, usually occurring on the tongue, inner lining of the cheeks, or lips, and the throat. 

What Causes Canker Sores?

Canker sores are not caused by viruses. The cause of canker sores is usually unknown. Possible causes of and triggers for canker sores may include: 

  • Mouth injuries, including biting the inside of the lip, vigorous tooth brushing, or braces rubbing against the cheek
  • Stress
  • Sodium lauryl sulfate (SLS), a common ingredient in toothpastes and mouthwashes
  • Nutritional deficiencies including low vitamin B12, iron, folate, or zinc
  • Hormonal changes during the menstrual cycle
  • Immune system problems
  • Genetics
  • Sensitivity to chocolate, coffee, strawberries, eggs, nuts, cheese, or spicy or acidic foods
  • Certain medical conditions, such as inflammatory bowel diseases (IBD)
  • A weakened immune system such as HIV/AIDS
  • Allergies
  • Dehydration
  • Certain medications
    • Beta-blockers
    • Immunosuppressants
    • Anticholinergic bronchodilators
    • Platelet aggregation inhibitors
    • Vasodilators
    • Protease inhibitors
    • Antibiotics
    • Nonsteroidal anti-inflammatory drugs (NSAIDs)
    • Antiretrovirals
    • Antihypertensives 
    • Chemotherapy medications

Canker sores are not contagious. They are not spread through saliva and cannot be transmitted by kissing, oral sex, or sharing toothbrushes or utensils with someone who has a canker sore. 

Canker sores are not the same as cold sores (fever blisters), which are an infection caused by the herpes virus.

What Are Symptoms of Canker Sores?

Canker sores are oral ulcers with a characteristic appearance: 

  • Round or oval shape
  • Red rim
  • Yellow colored fluid in center
  • Size varies from smaller than 1 mm to larger than 1 cm
  • Lesions usually start as a pinpoint-sized bump and develop into an ulcer over 1 to 2 days, reaching their largest size in 3 to 4 days before beginning to heal

They may have a burning or tingling feeling as they develop, and are often painful once the ulcer forms. 

How Do I Get Rid of Canker Sores?

Canker sores usually go away on their own within 2 weeks. The goal of treatment for canker sores is to relieve pain, speed healing, and decrease their recurrence.

Treatment for canker sores includes: 

  • Pain medicines
    • Topical anesthetics
  • Topical corticosteroids for mild to moderate canker sores
  • Topical antibiotics (mouth rinses, gels, or pastes) to control secondary infection 
  • Vitamins and dietary supplements if there are diagnosed nutritional deficiencies (e.g., vitamin B12, folate, iron, zinc) 
  • Proper oral hygiene
    • Brush twice daily with a soft toothbrush and floss regularly
    • Use mouthwash that does not contain alcohol to help reduce microbial overgrowth
    • Avoid toothpastes that contain sodium lauryl sulfate (SLS) if that causes or aggravates sores
  • Avoid behaviors that can injure the mouth
    • Don’t bite the inside of the lips or cheeks
    • Avoid foods that trigger sores 
    • Reduce sharp or rough edges on braces and dental restorations 

For severe cases of canker sores that do not respond to traditional therapies, treatments may include: 

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References
https://www.uptodate.com/contents/recurrent-aphthous-stomatitis?search=Canker%20Sores&source=search_result&selectedTitle=3~150&usage_type=default&display_rank=3

https://kidshealth.org/en/teens/canker.html

https://www.cedars-sinai.org/blog/canker-sores.html

https://www.sciencedirect.com/science/article/pii/S1882761613000811