A canker sore (aphthous ulcer) is characterized by painful, open sores in the inner lining of the oral cavity, gum or upper throat. It can be due to various causes including mechanical and chemical trauma. In seniors this may be seen with poorly fitting dentures, certain medication, diabetes and nutritional deficiencies among other causes. The most important symptom is pain and difficulty during eating and speaking. Although various treatment options for canker sores are available, most of the canker sores heal without treatment within one to two weeks. If the cause is not removed, these sores tend to recur.

Signs and Symptoms

Canker sores most commonly affect inner lining (mucosal covering) of the cheeks, tongue (the tip, sides, upper and lower side), lips, base of the gum, roof of the mouth (soft palate) and upper throat. It should not be confused with cold sores (fever blisters) that are due to a herpes simplex virus (HSV-1) infection and occur on the lips and the skin around it. However, cold sores can occur inside the mouth in some cases.

Canker sores usually begin with typical tingling or burning sensation on the mucosal membrane followed by red spot or bumps which breaks into an open sore with time. The ulcer appears as oval shaped yellow to white in color bordered by red margin (inflammation).

There are three different types of canker sores :

• Minor ulceration (most common) :
  – Size is 3 to 10mm.
  – Painful.
  – Heals within 2 weeks usually with no scar.
• Major ulceration :
  – Size is greater than 10 mm
  – Extremely painful
  – Takes longer time to heal (a month) leaving a scar.
• Herpetiform ulceration :
  – Most severe form.
  – Multiple ulcers (1 to 3mm).
  – Heals within a month without scarring.

The common symptoms of the canker sores are pain in the ulcer. The sores are very sensitive to spicy amd hot food. Ulcers present on the gum may be associated with pain in the teeth. Painful swelling of the local neck glands (lymph nodes) and fever may be present.

Causes of Canker Sores

Canker sores are commonly occurring oral ulcers with a prevalence ratebetween 15 to 30%. For most of the cases of canker sores, it is difficult to pinpoint the exact cause but there are some known risk factors.

• Consumption of certain citrus food like oranges and lemons.
• Injury to mucosal lining due to dental procedure, tooth cleaning, tongue or cheek biting, eating hard, abrasive foods like toast, dentures.
• Stress especially when associated with sleep deprivation and weight loss.
• Allergy to certain foods.
• Viral infection.
• Lack of vitamins such as vitamin B12, folic acid and iron.
• Intake of certain drugs including chemotherapy.
• Associated with other medical conditions like Crohn’s disease, Behcet disease, celiac disease.
• Poor immune defenses particularly in patients with long term poorly controlled diabetes.

Canker Sores Treatment

Usually canker sores do not need any treatment, with time they heal on their own. However, in some cases with extreme pain, ulcers that are very large or with repeated attacks, treatment is required.

• Mouth rinses to relieve pain and inflammation containing steroids or antibiotics (tetracycline).
• Ointments for oral mucosa such as benzocaine, fluocinonide may be used to relieve pain and hasten healing. Debacterol can be given to reduce healing time.
• Oral steroids are sometimes prescribed in severe cases that do not respond to other drugs.
• Nutritional supplements including vitamin B12, iron, folic acid or any other nutrient for the relevant deficiency.