Oral ulcers

A mouth ulcer (/ˈʌl-sɚ/, from Latin ulcus or American English: canker sores) is the name for the appearance of an open sore inside the mouth caused by a break in the mucous membrane or the epithelium on the lips or surrounding the mouth. The types of oral ulcers are diverse, with a multitude of associated causes including: physical or chemical trauma, infection from microorganisms, medical conditions or medications, cancerous and nonspecific processes. Once formed, the ulcer may be maintained by inflammation and/or secondary infection. Two common oral ulcer types are aphthous ulcers and cold sores or fever blisters. Cold sores around the lip are caused by the herpes simplex virus.

Minor physical injuries
Trauma to the mouth is a common cause of oral ulcers. A sharp edge of a tooth, accidental biting (this can be particularly common with sharp canine teeth, or Wisdom teeth), sharp, abrasive, or excessively salty food, poorly fitting dentures, dental braces or trauma from a toothbrush may injure the mucosal lining of the mouth resulting in an ulcer. These ulcers usually heal at a moderate speed if the source of the injury is removed (for example, if poorly fitting dentures are removed or replaced). .

It is also common for these ulcers to occur after dental work, when incidental abrasions to the soft tissues of the mouth are common. A dentist can apply a protective layer of petroleum jelly before carrying out dental work in order to minimize the number of incidental injuries to the soft mucosa tissues.

Chemical injuries
Chemicals such as aspirin or alcohol that are held or that come in contact with the oral mucosa may cause tissues to become necrotic and slough off creating an ulcerated surface. Sodium lauryl sulfate (SLS), one of the main ingredients in most toothpastes, has been implicated in increased incidence of oral ulcers.

Infection
Viral, fungal and bacterial processes can lead to oral ulceration. One way to contract pathogenic oral ulcerations is to touch your chapped lips without having washed your hands first. The reason that this happens is that the bacteria from your hands sinks into the tiny, open cuts caused by your chapped lips.

Viral
The most common is Herpes simplex virus which causes recurrent herpetiform ulcerations preceded by usually painful multiple vesicles which burst. Varicella Zoster (chicken pox, shingles), Coxsackie A virus and its associated subtype presentations, are some of the other viral processes that can lead to oral ulceration. HIV creates immunodeficiencies which allow opportunistic infections or neoplasms to proliferate.

Bacterial
Bacterial processes leading to ulceration can be caused by Mycobacterium tuberculosis (tuberculosis) and Treponema pallidum (syphilis).

Opportunistic activity by combinations of otherwise normal bacterial flora, such as aerobic streptococci, Neisseria, Actinomyces, spirochetes, and Bacteroides species can prolong the ulcerative process.

Fungal
Coccidioides immitis (valley fever), Cryptococcus neoformans (cryptococcosis), Blastomyces dermatitidis ("North American Blastomycosis") are some of the fungal processes causing oral ulceration.

Protozoans
Entamoeba histolytica, a parasitic protozoan is sometimes known to cause mouth ulcers through formation of cysts.

Immune system
Many researchers view the causes of aphthous ulcers as a common end product of many different disease processes, each of which is mediated by the immune system.

Aphthous ulcers are thought to form when the body becomes aware of and attacks chemicals which it does not recognize.

Immunodeficiency
Repeat episodes of mouth ulcers can be indicative of an immunodeficiency, signaling low levels of immunoglobulin in the oral mucous membranes. Chemotherapy, HIV, and mononucleosis are all causes of immunodeficiency with which oral ulcers become a common manifestation.

Autoimmunity
Autoimmunity is also a cause of oral ulceration. Mucous membrane pemphigoid, an autoimmune reaction to the epithelial basement membrane, causes desquamation/ulceration of the oral mucosa.

Allergy
Contact with allergens such as amalgam can lead to ulcerations of the mucosa.

Dietary
Vitamin C deficiencies may lead to scurvy which impairs wound healing, which can contribute to ulcer formation. Similarly deficiencies in vitamin B12, zinc have been linked to oral ulceration.

A common cause of ulcers is Coeliac disease, in which case consumption of wheat, rye, or barley can result in chronic oral ulcers. If gluten sensitivity is the cause, prevention means following a gluten-free diet by avoiding most breads, pastas, baked goods, beers etc. and substituting gluten-free varieties where available. Artificial sugars (Aspartame/Nutrisweet/etc) such as those found in diet cola and sugarless chewing gum, have been reported as causes of oral ulcers as well.

Flovent
Use of flovent without rinsing the mouth out afterwards may cause oral ulcers.

Cancer
Oral cancers can lead to ulceration as the center of the lesion loses blood supply and necroses. Squamous cell carcinoma is just one of these by tobacco.

Medical conditions associated with mouth ulcers
The following medical conditions are associated with mouth ulcers:
 * Behçet's disease
 * Bullous pemphigoid
 * Celiac disease (gluten sensitivity)
 * Crohn's disease
 * Gingivostomatitis
 * Leukoplakia
 * oral lichen planus
 * Lupus erythematosus
 * Neutropenia
 * Oral thrush
 * Ulcerative colitis
 * Infectious mononucleosis

Prevention
For trauma related cases, avoiding the offending source will prevent ulceration, but since such trauma is usually accidental, this type of prevention is not usually practical.

Individuals who have a high incidence of opportunistic bacterial infections subsequent to an accidental oral injury (biting etc.) can prevent the injury from becoming infected by directly bathing the wound with an anti-bacterial mouthwash for one minute every 12 hours for 2 days; it is important to use a small vessel to contain the solution as most antibacterial mouth washes that remain in the mouth for a full minute will have detrimental effects such as a prolonged impairment to the sense of taste and the potential loss of otherwise desirable flora. Quantities around 1 milliliter are more than sufficient. Ideally, the first treatment should occur within 3 hours.

Treatment
Symptomatic treatment is the primary approach to dealing with oral ulcers. If their cause is known, then treatment of that condition is also recommended. Adequate oral hygiene may also help in relieving symptoms. Typical antihistamines, antacids, corticosteroids or applications meant to soothe painful ulcers may be helpful, as may be oral analgesics such as paracetamol or ibuprofen and local anaesthetic lozenges, paints or mouth rinses such as benzocaine and avoiding spicy or hot foods may reduce pain. Rinsing the mouth out with brine (warm salted water) may help. An age old remedy is applying a small amount of vinegar to the ulcer, this relieves pain for a short amount of time. Ulcers persisting longer than three weeks may require the attention of a medical practitioner.