Although the exact cause of canker sores is unknown as of 2015, they may occur due to minor mouth injuries, food sensitivities, exposure to sodium lauryl sulfate, certain dietary deficiencies, hormonal and emotional factors and certain bacteria, as listed by Mayo Clinic. Certain other medical conditions may also cause canker sores.
Individuals who brush their teeth roughly, receive dental work or bite their cheeks may develop a canker sore due to a minor injury, according to Mayo Clinic. Sodium lauryl sulfate, an ingredient found in mouth rinses and toothpastes, may also trigger canker sores as well as sensitivities to foods such as coffee, strawberries, chocolate, cheese, eggs, nuts and high-acid food items. Individuals may be more likely to develop the sores if they do not consume enough iron, vitamin B-12 or folic acid. Women can also develop canker sores during their menstrual periods due to hormonal changes.
Researchers suspect that canker sores may develop as an allergic response to certain bacteria. The bacteria helicobacter pylori, which is responsible for peptic ulcers, is thought to play a role, as stated by Mayo Clinic. Conditions such as Celiac disease, Behcet's disease, human immunodeficiency virus and inflammatory bowel disease are also related to canker sores. Canker sores do not develop in response to the herpes virus, which is known to cause cold sores.
Some of the symptoms associated with canker sores may include development of painful sores within various regions of the mouth, general body weakness, increased temperature and swollen lymph nodes.
There is no cure for canker sores. However, their symptoms can be managed by avoiding acidic food, avoid chewing gum, brushing teeth with an extremely soft brush and using recommended tooth products, according to WebMD.