Aphthous ulcer causes

Overview
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. 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. 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. However, some studies find no connection between SLS in toothpaste and mouth ulcers.

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,, 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. 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.

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.