Fever Blisters/Cold & Cankers Sores > Cold Sores > Canker Sores
What are
canker sores?
Canker sores are a type of mouth ulcer. Some of the medical terms used
to refer to canker sores are "recurrent minor aphthous ulcers"
and "recurrent minor aphthous stomatitis". Canker sores are
the most common form of mouth ulcer.
What causes
canker sores?
The precise mechanism by which canker sores form has not been definitively
determined but it is quite likely that their development is related to
a reaction of an individual's own immune system.
Canker sores are thought to form when, for unexplained reasons, a person's immune system identifies the presence of chemical molecules which it does not recognize. The presence of these molecules activates an attack by the immune system's white blood cells, somewhat like when a person's immune system attacks a transplanted organ.
What triggers
outbreaks of canker sores?
Several factors which 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:
1.
Toothpastes and mouthwashes which contain sodium lauryl sulfate.
Research suggests that a person's use of products which contain sodium
lauryl sulfate ("SLS"), the most common foaming agent included
in the formulations of toothpastes and mouthwashes, can cause an increased
recurrence rate of canker sores. This is probably related to a drying
effect SLS has on the protective surface of oral tissues which in turn
can leave them vulnerable to irritants such as acidic foods.
Several studies have
reported that their participants who brushed with a toothpaste which was
free of SLS found that they had a reduction in the number of canker sores
they experienced. This reduction was found to be 81% in one study. In
this same study some of the participants reported that the canker sores
which did form were less painful than those which developed during those
time periods when they were using a toothpaste which did contain SLS.
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2.
Mechanical trauma.
People often recall some sort of trauma preceding the development 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 in one study felt that their
canker sores were precipitated by trauma.
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3.
Emotional stress / Psychic stress.
Psychological stress has been shown to adversely affect the health of
people in a number of ways. Persons who suffer from canker sores frequently
report that the timing of their ulcers coincide with periods of stress.
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4.
Nutritional deficiencies.
Researchers have discovered that some persons who suffer from canker sores
are found to have an underlying nutritional deficiency. Some of the deficiencies
which 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
5.
Allergies and sensitivities.
Allergies to foods and other substances have been postulated to be a trigger
for canker sore breakouts in some individuals. In these cases, any substance
which comes into contact with oral tissues must be considered a potential
causative agent. If an allergy is suspected a patient 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 which research has suggested can trigger outbreaks of canker sores in some individuals 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
6.
Hormonal changes.
Some women feel they find a relationship between the presence of canker
sores and certain phases of their menstrual period. It has also been reported
that women may notice a remission of canker sores during pregnancy. Neither
of these observations, however, has been adequately documented or explained
by research.
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7.
Genetics.
Some researchers have felt 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.
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8.
Infectious agents (bacteria and viruses).
The fact that agents associated with 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.
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9.
Medical conditions.
Several different medical conditions can be associated with the presence
of both canker sores and other forms of aphthous ulcers. For those patients
who experience persistent difficulties with canker sores, consideration
must be given to the presence of an underlying undiagnosed systemic disease.
Some of the medical conditions which 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.
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10.
Medications.
Nonsteroidal anti-inflammatory drugs (NSAIDs), beta blockers, chemotherapeutic
agents, and nicorandil have all been suggested as having a relationship
to the occurrence of canker sores.
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