There may be an inherited tendency to develop canker sores, as they often run in families. There may also be an immune system link. Ulcers may develop in response to a mouth injury such as dental procedures or aggressive tooth cleaning.
Canker sores are thought to form when, for unexplained reasons, a person's immune system identifies the presence of chemical molecules that it does not recognize. The presence of these molecules activates an attack by the immune system's lymphocytes (a type of white blood cell), somewhat like when a person's immune system attacks a transplanted organ. The carnage of the lymphocytes' attack on these unrecognized molecules results in the type of mouth ulcers we term canker sores.
Several factors that seem to trigger outbreaks of canker sores have been identified. Any one or a combination of the following items may play a significant role in the formation of canker sores for any one individual:
Toothpastes and mouthwashes that contain sodium lauryl sulfate.
Research suggests that a person's use of products that contain sodium lauryl sulfate ("SLS"), a foaming agent found in most toothpaste and mouthwash formulations, can cause an increased recurrence rate of canker sores. This is probably due to a drying effect SLS has on the protective surface of oral tissues. Once this protective layer has been compromised the tissue underneath is more vulnerable to irritants such as acidic foods.
Several studies have reported that participants who brushed with a toothpaste that was SLS free found that they experienced a reduction in the number of canker sores that formed. This reduction was found to be 81% in one study. In this same study some of the participants reported that the canker sores that did form were less painful than those that developed during those time periods when they had been using a toothpaste that did contain SLS.
People will often recall some sort of trauma preceding the formation of their canker sores. This trauma might take the form of a self-inflicted bite, irritation from a sharp tooth, or possibly trauma from some type of food such as a crisp chip. 38% of the participants of one study felt that their canker sores were precipitated by trauma.
Emotional stress / Psychic stress.
Psychological stress has been shown to adversely affect the health of people in a number of ways. Many people who suffer from canker sores will frequently report that the timing of their ulcers coincide with periods of stress.
Researchers have discovered that some people who suffer from canker sores have an underlying nutritional deficiency. Some of the nutritional deficiencies that have been correlated with the presence of canker sores are:
* Vitamin deficiencies: B1, B2, B6, B12, C
* Other nutrients: zinc, folic acid, iron, selenium, calcium
Allergies and sensitivities.
Allergies to foods and other substances have been postulated as being a trigger for canker sore breakouts. Any substance that comes into contact with the person's oral tissues must be considered a potential causative agent. If an allergy is suspected the individual might choose to maintain a diary so to help them and their dentist identify the most likely candidates associated with the causation of their sores. In some cases allergy testing might be considered.
Some of the substances identified by researchers as being potential triggers for canker sore outbreaks are:
* Cereal grains: buckwheat, wheat, oats, rye, barley, the gluten protein found in grains
* Fruits and vegetables: lemons, oranges, pineapples, apples, figs, tomatoes, strawberries
* Dairy: milk, cheeses
* Other foods: nuts, chocolate, shellfish, soy, vinegar, French mustard
* Additives: cinnamonaldehyde (a flavoring agent), benzoic acid (a preservative)
* Other substances: toothpastes, mints, gums, dental materials, metals, medications
Some women have reported that they find a relationship between the presence of canker sores and certain phases of their menstrual period. It has also been reported that a woman may notice a remission of canker sores during pregnancy. Neither of these observations has been adequately documented or explained by research.
Some researchers have felt that they have identified a genetic predisposition for canker sores. One study found that 35% of those persons who experience canker sores have at least one parent who suffers from these ulcers also. Another study found that 91% of identical twins both suffered from canker sores whereas only 57% of fraternal twins did.
Infectious agents (both bacterial and viral).
The fact that substances characteristic of bacterial and viral infections have been isolated from canker sores suggests that bacteria or viruses could be causative in the formation of these mouth ulcers.
Several different medical conditions can be associated with the presence of canker sores (and other forms of aphthous ulcers as well). For those patients who experience persistent difficulties with canker sores consideration must be given to the presence of an underlying undiagnosed systemic disease and the need for an evaluation and testing by a physician.
A few of the medical conditions that have been associated with the presence of these ulcers are: Behcet's disease, neutrophil dysfunction diseases, inflammatory bowel diseases (celiac and Crohn's), and HIV-AIDS.
Nonsteroidal anti-inflammatory drugs (NSAIDs), beta blockers, chemotherapeutic agents, and nicorandil have each been reported as possibly having a relationship with outbreaks of canker sores.
I get them often, mostly when I'm not on birth control and right about to get my peroid. I usually get a canker sore or a cold sore just about every month. They come earlier in my cycle and less often when I'm on birth contol.