A canker sore is a small, shallow ulcer inside the mouth that is often located on the tongue, gums or inside the cheeks and can last up to a week or longer. They are painful and can interfere with the ability to eat or even talk.
While there is no definite cause of a canker sore, there are a number of known triggers, including stress, hormone changes, mouth injuries, medications and allergies, to name a few. Canker sores can also be representative of underlying health conditions, such as an impaired immune system, nutritional problems and the deficiency of vitamin B-12, zinc, folic acid or iron. If an individual experiences frequent canker sores, he or she may have a genetic predisposition to them or be suffering from something more serious, like Lupus or a gastrointestinal tract disease such as celiac disease or Crohn’s disease.
Unfortunately, there is no known cure for canker sores. However, pain from a canker sore normally subsides in a few days, and usually heals without treatment in a week or two. During this timeframe, it is wise to avoid certain citrus and acidic foods like lemons, oranges, apples, strawberries, pineapples and tomatoes, as each is known to irritate present canker sores. You might also consider using topical, over-the-counter pain medications to relieve pain or discomfort, or take advantage of popular home remedies like rinsing with saltwater or swishing and spitting a mixture of equal amounts of magnesia and Benadryl liquid.
If your canker sores are large, painful or persistent, make sure to consult a dentist. He or she may be able to prescribe an ointment or mouth rinse to help further reduce the pain and irritation.
Resources: WebMD, Mayo Clinic, MedicineNet