Aphthous ulcer

An aphthous ulcer or canker sore is a type of mouth ulcer which presents as a painful open sore inside the mouth, 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 are 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, 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.[1][2][3]

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Presentations of aphthous stomatitis

Aphthous ulcers are classified according to the diameter of the lesion.

Recurrent Aphthous Stomatitis

Recurrent Aphthous Stomatitis is a T-cell mediated localized destruction of oral mucosa associated with an increased relative ratio of CD8+ T-cells to CD4+ T-cells.

Minor aphthous ulcerations

This is the most common and least severe form of the disease. Aphthous ulcers develop in childhood and adolescence, and continue sporadically throughout life. Aphthous ulcers occur exclusively on non-keratinized, movable mucosa, such as buccal (cheeks) and lingual mucosa, the floor of the mouth, and the soft palate. It is characterized as a yellow-gray ulcer surrounded by an erythematous halo less than 10 mm in diameter. They tend to heal without scarring in 7–10 days. Typical treatment is with topical steroids, although treatment is not necessary for healing to occur.

Major aphthous ulcerations

Major aphthous ulcers have the same appearance as minor ulcerations, but are greater than 10 mm 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.

Herpetiform aphthous ulcerations

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.^[1]

Symptoms

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.

Causes

The exact cause of aphthous ulcers is unknown. Factors that provoke them include stress, fatigue, illness, injury from accidental biting, hormonal changes, menstruation, sudden weight loss, food allergies, the foaming agent in toothpaste (SLS), and deficiencies in vitamin B12, iron, and folic acid.^[2] Some drugs, such as nicorandil, also have been linked with 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.[4][5][6] Physical trauma, such as that caused by toothbrush abrasions, laceration with sharp foods 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. contain Sodium lauryl sulfate (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.^[3][4][5] However, some studies find no connection between SLS in toothpaste and mouth ulcers.^[6]

Artificial sugars, such as those found in diet cola and sugarless gum, have been reported as causes of aphthous ulcers as well. They can also be linked to an increased intake of acids such as ascorbic acid (one form of Vitamin C) or citric acid. In this case the sores disappear after intake decreases (for example, by substituting ascorbate salts for ascorbic acid).

According to small-scale experiments by one patent applicant Hau, (6,248,718 ), topical preparations of high doses of penicillin resulted in accelerated healing of mouth ulcers.

There is a commonly held belief that another cause of aphthous ulcers is gluten intolerance (Celiac disease), whereby consumption of wheat, rye, barley and sometimes oats can result in chronic mouth ulcers. However, two small studies of patients with Celiac disease have demonstrated no link between the disease and aphthous ulcers.^[7][8] If patients with aphthous ulcers do happen to have gluten intolerance, they may experience benefit in eliminating breads, pastas, cakes, pies, scones, biscuits, beers and so on from their diet and substituting gluten-free varieties where available.^[7]

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.^[9] 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.^[9]

Repeat episodes of aphthous ulcers can be indicative of an immunodeficiency, signalling low levels of immunoglobulin in the mucous membrane of the mouth.^{[citation needed]} Certain types of chemotherapy cause mouth ulcers as a side effect.^[10] Mouth ulcers may also be symptoms or complications of several diseases listed in the following section. The treatment depends on the believed cause.

Pain relief and healing

Aphthous ulcers normally heal without treatment within 1 to 2 weeks. Good oral hygiene should be maintained, and spicy, acidic, and salty foods and drinks are best avoided, as they may irritate existing ulcers. Strong mouthwashes such as Listerine have also been known to cause irritation because of their strong ingredients, and many oral care professionals discourage the use of these mouthwashes until the mouth ulcers have healed.

Pain can be mitigated by an OTC pain-relieving and/or protectives gel, such as Anbesol, Bonjela, Campho-Phenique, Orabase B, Orajel, Zilactin, Canker Cover or Kanka.

Triamcinolone Acetonide dental paste can be very effective; the steroid reduces the immune system's response in the area of the ulcer. It is available by prescription only for bigger pack size - 10g or over the counter for smaller pack size - 5g in pharmacies in the UK.

A recent study of the Oral-B product Amosan suggests that it may reduce anaerobic bacteria, such as those found in oral wounds. The study did not, however, demonstrate the efficacy of the product in treating mouth ulcers.^[11]

Tincture of benzoin can be used as a protectant for recurring aphthous ulcers, by forming a layer over the sore and protecting it from further irritation.

Home remedies

Some home remedies that have been suggested include:

• Licorice Root (Glycyrrhiza) in the form of over-the-counter medicated disk patches may help heal or reduce the growth of canker sores if applied early on.[7]

Antacid techniques suggested include the following:

• Swab the ulcers with Milk of Magnesia.[8]
• Make a paste of baking soda and water; apply directly to the ulcers.[9]
• Make a mix of half milk of magnesia and half Benadryl, and hold in the mouth for up to 3 minutes.^[12]

Treatment for severe cases

In very severe cases, a doctor may prescribe a steroid treatment. One such steroid is methylprednisolone (usually in a dose-pack), taken orally for a period of 7 days. Alternatively, the doctor may inject a steroid directly into the site of the ulcer (this treatment is performed with kenalog. Between 0.2 and 0.4 ml of kenalog is injected into the site of the ulcer, which will usually be completely healed 72 to 96 hours after the injection).

Patients in whom ulcers do not respond to local treatment may benefit from a short course of pulsed prednisone.

Some dentists recommend a sulfuric acid solution for treating mouth ulcers, such as debacterol.

Thalidomide has been effective in unresponsive aphthous stomatitis. Thalidomide has been used successfully generally to treat various inflammatory conditions characterized by tissue infiltration with polymorphonuclear leukocytes (PMNLs). Therapeutic benefit has been attributed to depression of PMNL chemotaxis and, possibly, PMNL phagocytosis. However, adverse effects can be both problematic and clinically significant.

Another chemical treatment option is the application of silver nitrate to cauterize the sore. In clinical trials it was found that this treatment reduced pain in patients by 70% with one application but had no effect on healing compared to placebo.^[13]

Another choice doctors have is to prescribe Aphthasol, the only Food and Drug Administration (FDA) approved treatment specifically indicated for Aphthous ulcers.

Controversial therapies include levamisole, colchicine, gamma-globulin, dapsone, estrogen replacement, MAOIs, and tetracycline. [10]

Some evidence supports treatment with tetracycline. Tetracycline oral mouth rinse (ie, swish orally and swallow) decreases healing time and pain severity and duration. Whether this benefit is due to a direct antimicrobial effect, tetracycline's anti-inflammatory properties^[14] or to an inhibitory effect on chemotaxis and chemotoxicity is not known.

The miracle cures that are advertised should be viewed with skepticism. However, aqueous sulphuric acid products as listed above can provide significant pain relief, if not treating the underlying causes.

Prevention

Oral and dental measures

• Regular use of mouthwash may help prevent or reduce the frequency of sores.^[15]

• 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 simply 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.^[16][17][18]

• 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.

• Take caution when brushing or flossing teeth, and be extra careful when using a toothpick.

Nutritional therapy

• Zinc deficiency has been reported in people with recurrent mouth ulcers.^[19]The few small studies looking into the role of zinc supplementation have mostly reported positive results particularly for those people with deficiency, ^[20]although some research has found no therapeutic effect.^[21]

See also

• Mouth ulcer

References