An aphthous ulcer
(aka canker sore
) is a type of oral ulcer
which presents as a painful open sore
inside the mouth
or upper throat
, caused by a break in the mucous membrane
. The condition is also known as aphthous stomatitis,
and alternatively as "Sutton's Disease," especially in the case of multiple or recurring ulcers.
The term aphtha means ulcer; it has been used for many years to describe areas of ulceration on mucous membranes. Aphthous stomatitis is a condition which is characterized by recurrent discrete areas of ulceration which are almost always painful. Recurrent aphthous stomatitis (RAS) can be distinguished from other diseases with similar-appearing oral lesions, such as certain viral exanthems or Herpes simplex, by their tendency to recur, and their multiplicity and chronicity. Recurrent aphthous stomatitis is one of the most common oral conditions. At least 10% of the population suffers from it. Women are more often affected than men. About 30–40% of patients with recurrent aphthae report a family history.
Aphthous ulcers are classified according to the diameter of the lesion.
"Minor aphthous ulcers" indicate that the lesion size is between 3-10mm. The appearance of the lesion is that of an erythematous halo with yellowish or grayish color. Pain is the obvious characteristic of the lesion.
Major aphthous ulcers
have the same appearance as minor ulcerations, but are greater than 10mm in diameter and are extremely painful. They usually take more than a month to heal, and frequently leave a scar
. These typically develop after puberty
with frequent recurrences. They occur on moveable non-keratinizing
oral surfaces, but the ulcer borders may extend onto keratinized surfaces. The lesions heal with scarring and cause severe pain and discomfort.
This is the most severe form. It occurs more frequently in females, and onset is often in adulthood
. It is characterized by small, numerous, 1–3 mm lesions that form clusters. They typically heal in less than a month without scarring. Palliative
treatment is almost always necessary.
Aphthous ulcers often begin with a tingling or burning sensation at the site of the future mouth ulcer. In a few days, they often progress to form a red spot or bump, followed by an open ulcer.
The aphthous ulcer appears as a white or yellow oval with an inflamed red border. Sometimes a white circle or halo around the lesion can be observed. The grey-, white-, or yellow-colored area within the red boundary is due to the formation of layers of fibrin, a protein involved in the clotting of blood. The ulcer, which itself is often extremely painful, especially when agitated, may be accompanied by a painful swelling of the lymph nodes below the jaw, which can be mistaken for toothache.
The exact cause of many aphthous ulcers is unknown. Factors that provoke them include citrus (orange juice, lemons, acidic items, etc.), stress
, injury from accidental biting
, sudden weight loss
, food allergies
, the foaming agent in toothpaste (sodium lauryl sulfate
or SLS), and deficiencies in vitamin B12
, and folic acid
. Some drugs, such as nicorandil
, also have been linked to mouth ulcers. In some cases they are thought to be caused by an overreaction by the body's own immune system
Trauma to the mouth is the most common trigger of aphthous ulcers. Physical trauma, such as that caused by toothbrush abrasions, laceration with sharp or abrasive foods (toast) or objects, accidental biting (particularly common with sharp canine teeth), or dental braces can cause mouth ulcers by breaking the mucous membrane. Other factors, such as chemical irritants or thermal injury, may also lead to the development of ulcers. The large majority of toothpastes sold in the U.S. contains SLS, which is known to cause aphthous ulcers in certain individuals. Using a toothpaste without SLS will reduce the frequency of aphthous ulcers in persons who experience aphthous ulcers caused by SLS.
However, some studies find no connection between SLS in toothpaste and mouth ulcers.
A possible cause of aphthous ulcers in a susceptible population is gluten intolerance (Celiac disease), whereby consumption of wheat, rye, barley and sometimes oats, results in chronic mouth ulcers. However, two small studies of patients with Celiac disease did not demonstrate a link between the disease and aphthous ulcers. On the other hand, one of the same studies concluded that one-third of its test group found relief from canker sores after eliminating gluten from the diet This means observing a strict diet, eliminating breads, pastas, cakes, pies, scones, biscuits, beers and so on from the diet and substituting gluten-free varieties where available. The opportunity to go into such a drastic measure is to be balanced with its potential benefits.
Although the exact cause is not known, aphthous ulcers are thought to form when the body becomes aware of and attacks molecules which it does not recognize. The presence of the unrecognized molecules garners a reaction by the T-cells, which trigger a reaction that causes the damage of a mouth ulcer. People who get these ulcers have lower numbers of regulatory T-cells.
Repeat episodes of aphthous ulcers can be indicative of an immunodeficiency, signalling low levels of immunoglobulin in the mucous membrane of the mouth. Certain types of chemotherapy cause mouth ulcers as a side effect.
Mouth ulcers may also be symptoms or complications of several diseases listed in the following section. The treatment depends on the believed cause.
Suggestions to reduce the pain
caused by an ulcer include avoiding spicy food
, eating plain vanilla yogurt, rinsing with salt water
or over-the-counter mouthwashes
, proper oral hygiene
and non-prescription local anesthetics
. Active ingredients
in the latter generally include benzocaine
or choline salicylate
. Anaesthetic mouthwashes containing benzydamine hydrochloride have not been shown to reduce the number of new ulcers or significantly reduce pain, and evidence supporting the use of other topical anaesthetics is very limited though some individuals may find them effective. In general their role is limited; their duration of effectiveness is generally short and does not provide pain control throughout the day; the medications may cause complications
in children. Evidence is limited for the use of antimicrobial
mouthwashes but suggests that they may reduce the painfulness and duration of ulcers and increase the number of days between ulcerations, without reducing the number of new ulcers. Liquorice root
extract may help heal or reduce the growth of canker sores if applied early on and is available in over-the-counter patches. A mixture of equal parts water and 3% hydrogen peroxide
, forming a 1.5% hydrogen peroxide solution, applied to the ulcer may speed healing, and applying Milk of Magnesia
after this treatment can relieve discomfort.
preparations containing hydrocortisone
hemisuccinate or triamcinolone acetonide
to control symptoms are effective in treating severe aphthous ulcers. However, if the ulceration is caused by a virus, steriods are contraindicated.
Multiple ulcers may be treated with an antiviral medication. The application of silver nitrate will cauterize the sore; a single treatment reduces pain but does not affect healing time.
Ulcers larger than 1 cm or lasting longer than two weeks may require treatment with tetracycline though in children it can cause tooth discoloration if the teeth are still developing. The use of tetracyclin is controversial, as is treatment with levamisole, colchicine, gamma-globulin, dapsone, estrogen replacement and monoamine oxidase inhibitors.
Oral and dental measures
- Regular use of mouthwash may help prevent or reduce the frequency of sores. In fact, informal studies suggest that mouthwash may help to temporarily relieve pain.
- In some cases, switching toothpastes can prevent mouth ulcers from occurring with research looking at the role of sodium dodecyl sulfate (sometimes called sodium lauryl sulfate, or with the acronymes SDS or SLS), a detergent found in most toothpastes. Using toothpaste free of this compound has been found in several studies to help reduce the amount, size and recurrence of ulcers.
- Dental braces are a common physical trauma that can lead to mouth ulcers and the dental bracket can be covered with wax to reduce abrasion of the mucosa. Avoidance of other types of physical and chemical trauma will prevent some ulcers, but since such trauma is usually accidental, this type of prevention is not usually practical.
- Avoiding citrus (sour) in your diet (lemons, oranges, acidic drinks, citric foods, and citric candies).
- Zinc deficiency has been reported in people with recurrent mouth ulcers. The few small studies looking into the role of zinc supplementation have mostly reported positive results particularly for those people with deficiency, although some research has found no therapeutic effect.