An aphthous ulcer, also known as a canker sore, is a type of oral ulcer, which presents as a painful open sore inside the mouth or upper throat (including the uvula) 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 major, 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 has it, and women are more often affected than men. About 30–40% of patients with recurrent aphthae report a family history.
Aphthous ulcers usually begin with a tingling or burning sensation at the site of the future aphthous 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 gray-, 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; another symptom is fever. A sore on the gums may be accompanied by discomfort or pain in the teeth.
The exact cause of many aphthous ulcers is unknown but citrus fruits (e.g. oranges and lemons), lack of sleep, illness, physical trauma, stress, hormonal changes, sudden weight loss, food allergies, immune system reactions and deficiencies in vitamin B12, iron, and folic acid may contribute to their development. Nicorandil and certain types of chemotherapy are also linked to aphthous ulcers.
Trauma to the mouth is the most common trigger. Physical trauma, such as that caused by toothbrush abrasions, laceration with sharp or abrasive foods (such as toast, potato chips or other objects, accidental biting (particularly common with sharp canine teeth), after losing teeth, or dental braces can cause aphthous ulcers by breaking the mucous membrane. Other factors, such as chemical irritants or thermal injury, may also lead to the development of ulcers. Using a toothpaste without sodium lauryl sulfate (SLS) may reduce the frequency of aphthous ulcers but some studies have found no connection between SLS in toothpaste and aphthous ulcers. Celiac disease has been suggested as a cause of aphthous ulcers; small studies of patients (33% or 1 out of 3) with Celiac disease did demonstrate a conclusive link between the disease and aphthous ulcers vs control group (23%) but some patients benefited from eliminating gluten from their diet.
Oral aphthous ulcers are also commonly seen in Crohn's disease.
There is no indication that aphtous ulcers is related to menstruation, pregnancy and menopause. Smokers appear to be affected less often.
Treatment can be considered in three stages: First, the protection of the wound from further physical trauma inside the mouth (such as braces, or contusions caused by the teeth) which can be accomplished with topical ointment protective barriers and care with brushing. Second, a temporary change in diet to remove chemical irritants such as spicy or acidic foods which can prolong the sores. Third, with medicine (ingested or topical) or 'natural' remedies including lysine supplements and licorice root to speed the rate of healing.
Vitamin B12 (1 mg dissolved under the tongue each evening) has been found to be effective in treating recurrent aphthous ulcers, regardless of whether there is a vitamin deficiency present.
Suggestions to reduce the pain caused by an ulcer include: avoiding spicy food, 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, benzydamine or choline salicylate.
Anesthetic 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 anesthetics 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 aphthous ulcers if applied early on and is available in over-the-counter patches.
Dentists can also provide laser treatments.
Powdered alum is commonly cited as a home remedy for canker sores. Because ingesting alum can be harmful (or even fatal) to humans, care should be exercised when using it to treat canker sores. Be sure to rinse the mouth thoroughly with clear water and try not to swallow the alum.
According to MedlinePlus Medical Encyclopedia, milk of magnesia is useful against canker sores (aphthous ulcer) when used topically.
Applying Baking Soda to the canker sore has been known to accelerate healing time.
Corticosteroid preparations containing hydrocortisone hemisuccinate or triamcinolone acetonide to control symptoms are effective in treating severe aphthous ulcers.
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. though in children it can cause tooth discoloration if the teeth are still developing. The use of tetracycline is controversial, as is treatment with levamisole, colchicine, gamma-globulin, dapsone, estrogen replacement and monoamine oxidase inhibitors.
A newer medication known as Debacterol, a topical sulfuric acid/phenolics solution used as a cauterizing agent has been shown to reduce pain and decrease healing time. However, it has only recently been approved by the FDA.
Canker sores contain elevated levels of "activated" mast cells. Activated mast cells secrete histamines (known to cause allergy) and leukotrienes (known to cause inflammation). Aphthasol (Amlexanox 5%) is known to inhibit histamine and leukotriene secretion by mast cells. The application of Amlexanox at prodromal stage prevents/reduces ulceration in humans. Therefore Amlexanox inhibits these processes before tissue damage occurs. Aphthasol is the first and only FDA-approved prescription drug indicated for the treatment of canker sores.
Severe outbreaks are sometimes treated with a corticosteroid such as prednisone and anti-viral medications such as acyclovir.
Oral and dental measures
Regular use of non-alcoholic 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 aphthous 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 aphthous 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.
Zinc deficiency has been reported in people with recurrent aphthous 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.