Aphthous ulcer

Mouth ulcer on the lower lip

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 suffers from it. Women are more often affected than men. About 30–40% of patients with recurrent aphthae report a family history.

Presentation

Lge aphthous ulcer on the lower lip

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

Minor ulceration

"Minor aphthous ulcers" indicate that the lesion size is between 3-10 mm. The appearance of the lesion is that of an erythematous halo with yellowish or grayish color. Extreme pain is the obvious characteristic of the lesion. When the ulcer is white or grayish, the ulcer will be extremely painful and the infected lip may swell.

Major 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 movable 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 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.

Symptoms

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 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; another symptom is fever. A sore on the gums may be accompanied by discomfort or pain in the teeth.

Causes

The exact cause of many aphthous ulcers is unknown but citrus fruits (e.g. oranges and strawberries), lack of sleep, illness, physical trauma, hormonal changes, menstruation, 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) or 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 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 with Celiac disease did not demonstrate a conclusive link between the disease and aphthous ulcers but some patients benefited from eliminating gluten from their diet.

Treatment

Non-prescription treatments

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.

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 aphthous ulcers if applied early on and is available in over-the-counter patches.

Dentists can also provide laser treatments with good results.

A thick paste made of crushed aspirin and water applied to the canker sore may reduce pain after the initial burning sensation caused by application subsides, and may prevent the sore from further irritation allowing it to heal more quickly.

Prescription treatments

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.

Alternatively, a newer medication known as Debacterol, a topical sulfuric acid/phenolics solution used as a cauterizing agent has proven to be a highly effective treatment against canker sores, which has shown significantly to reduces pain and increases healing time. However, Debacterol is not yet FDA approved.

Canker sores contain lots 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.

OraDiscA-(amlexanox 2mg) is a mucoadhesive, water-erodible disc incorporating 2mg of Amlexanox for the treatment and prevention of aphthous ulcers. A thin, flexible, biodegradable composite film is composed of a backing layer attached to a layer which contains both the mucosal adhesive polymers and Amlexanox. While adhering to the mucosal tissue, the polymer absorbs moisture, commences disintegration while delivering the active drug Amlexanox into the lesion. Complete erosion and drug release occurs in less than 60 minutes.

Severe outbreaks are sometimes treated with a corticosteroid such as prednisone and anti-viral medications such as acyclovir. Prednisone can help, but can have some serious side effects which should also be considered.

Prevention

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.

Nutritional therapy

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.