If you haven’t had one yet, consider yourself blessed. Canker sores a.k.a. Recurrent Aphthous Stomatitis affects 20% of the general population. These little suckers can pop up anywhere there is non-keratinized tissues of the oral cavity (usually anywhere except on your gums where the teeth are). So you should not see these on the little ulcers on your hard palate or gingiva(gums)1.
Clinical Presentation:
- Small (less than one centimeter) diameter, for the minor variant
- Red halo around the outside of a yellowish-grayish-whitish pseudomembranous center
- Typically on the inside of the lips, tongue, cheeks or even on the floor of the mouth
- Painful ulcer that hangs around for 10-14 days
- Usually only one ulcer at a time, but some individuals may experience up to 5. If there are more than five this may indicate a more pressing issue
- Individuals may notice a prodromal burning sensation 2-48 hours before presentation in the oral cavity1.

Different Types of Canker Sores (Recurrent Aphthous Stomatitis-RAS)
- Minor RAS: Most common type of aphthous ulcers, these are the ones that can randomly pop up on non-keratinized tissues and are usually under one centimeter in diameter and heal without scarring in 10-14 days. Minor RAS is usually seen at an earlier age (10-19years)4.
- Major RAS: These ulcers will be larger than one centimeter in diameter and most commonly seen lips, soft palate, and on the pharyngeal arches. These nasty things can hang around for 6 weeks and heal with scarring.
- Herpetiform Aphthae: These are crops of ulcers similar to the herpes ulcers, but do not have a vesicular pre-stage as does herpes. Usually, these are 2-3 millimeters in diameter and there can be up to 100 of them. They are usually seen in women and at a later age2,3.
Why Do We Get Them?
- Genetics: Some people just have the unlucky genetic predisposition to getting these ulcers. So if your parents had them, you might too.
- Trauma: A sharp tooth, dental injections, rubbing from braces, e.t.c., can all cause recurrent aphthous ulceration.
- Drugs: Certain drugs have the potential to to cause the ulceration seen with RAS.
- Nutritional Deficiencies: Deficiencies in: Folic acid, Iron, Zinc, and B Vitamins all have the potential to predispose an individual to RAS
- Gluten Sensitivity or Inflammatatory Bowel Disease: Oftentimes, the ulcers may be the only sign of these medical conditions
- Sodium lauryl sulfate-containing toothpaste: Some studies show that reducing the use of toothpastes with this ingredient can help decrease the occurrence of RAS
- Stress: Psychological stress appears to have a direct impact on triggering the formation of an ulcer
- Bacteria and Viruses: There is some data that suggests there are certain strains of bacteria and viruses that have the potential to cause these ulcers3.
- Sometimes we just don’t know, could be hormones, allergies, or diet.
Management
As noted above, most of the recurrent aphthous stomatitis minor ulcers heal without scarring on their own in 10-14 days. So really, no treatment is needed. That being said, if you are prone to getting them often or they are particularly painful, certainly there is something to help manage?
First up on the list is confirming that you are only experience the minor form of RAS. If not, consultation with a specialist, an oral pathologist, may be warranted.
Next, determine if there is a trigger/cause/time of year/ whatever it may be that initiates the ulcer formation. If this is understood you can then try your best to avoid that trigger.
If you just can’t stand the pain, or the annoyance, of the canker sore your next step could be a topical paste applied to the affected area. This can be in the form of an over-the-counter such as Orajel or a if that is not enough, your dentist can prescribe a topical steroid gel to place over the ulcer. Some dentists may even offer to laser the ulcer off to decrease healing time, but this does not mean that it won’t still come back.
Orajel Mouth Sore Pain Relief Gel, 0.18 oz — Link to Orajel for canker sores.
Summary: Canker sores, a.k.a. Recurrent Aphthous Stomatitis, can be a painful annoyance. If you get them often and there are more than 4-5 at a time and/or they are bigger than one centimeter you should get a referral to an Oral Pathologist to make sure something else is not afoot. If you are sure it is just the minor form of RAS, try and determine the trigger and avoid said trigger. If the annoyance is too much, try out the over-the-counter topical gels. Or talk to your dentist and see if they would recommend a prescription for topical steroid gel.
- Akintoye, S. O., & Greenberg, M. S. (2014). Recurrent aphthous stomatitis. Dental clinics of North America, 58(2), 281–297. https://doi.org/10.1016/j.cden.2013.12.002
- Scully, C., & Porter, S. (1989). Recurrent aphthous stomatitis: current concepts of etiology, pathogenesis and management. Journal of oral pathology & medicine : official publication of the International Association of Oral Pathologists and the American Academy of Oral Pathology, 18(1), 21–27.
- Preeti, L., Magesh, K., Rajkumar, K., & Karthik, R. (2011). Recurrent aphthous stomatitis. Journal of oral and maxillofacial pathology : JOMFP, 15(3), 252–256. https://doi.org/10.4103/0973-029X.86669
- Ship, J. A., Chavez, E. M., Doerr, P. A., Henson, B. S., & Sarmadi, M. (2000). Recurrent aphthous stomatitis. Quintessence international (Berlin, Germany : 1985), 31(2), 95–112.
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