The precise cause of canker sores remains unclear, though researchers suspect that a combination of several factors contributes to outbreaks, even in the same person.
Possible triggers for canker sores include:
- A minor injury to your mouth from dental work, overzealous brushing, sports mishaps, spicy or acidic foods, or an accidental cheek bite
- Toothpastes and mouth rinses containing sodium lauryl sulfate
- Food sensitivities, particularly to chocolate, coffee, strawberries, eggs, nuts, cheese and highly acidic foods, such as pineapple
- A diet lacking in vitamin B-12, zinc, folate (folic acid) or iron
- An allergic response to certain bacteria in your mouth
- Helicobacter pylori, the same bacteria that cause peptic ulcers
- Hormonal shifts during menstruation
- Emotional stress
Canker sores may also occur because of certain conditions and diseases, such as:
- Celiac disease, a serious intestinal disorder caused by a sensitivity to gluten, a protein found in most grains
- Inflammatory bowel diseases, such as Crohn's disease and ulcerative colitis
- Behcet's disease, a rare disorder that causes inflammation throughout the body, including the mouth
- A faulty immune system that attacks healthy cells in your mouth instead of pathogens, such as viruses and bacteria
- HIV/AIDS, which suppresses the immune system
Unlike cold sores, canker sores are not associated with herpes virus infections.
Mar. 24, 2012
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- Canker sores, cold sores & common mouth sores. American Dental Association. http://www.ada.org/2982.aspx?currentTab=1. Accessed Feb. 2, 2012.
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- Rakel D. Integrative Medicine. 2nd ed. Philadelphia, Pa.: Saunders Elsevier; 2007. http://www.mdconsult.com/das/book/body/208746819-2/0/1494/0.html. Accessed Feb. 6, 2012.
- Goldstein BG, et al. Oral lesions. http://www.uptodate.com/home/index.html. Accessed Feb. 6, 2012.
- AskMayoExpert. Recurrent aphthous ulcers. Rochester, Minn.: Mayo Foundation for Medical Education and Research; 2011.
- Morelli V, et al. Alternative therapies for common dermatologic disorders, part 2. Primary Care Clinics in Office Practice. 2010;37:285.
- Bailey J, et al. What is the most effective way to treat recurrent canker sores? The Journal of Family Practice. 2011;60:621.
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- Gibson LE (expert opinion). Mayo Clinic, Rochester, Minn. Feb. 21, 2012.
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