Diseases & Conditions
A small painful ulcer on the inside of the mouth, lip, or underneath the tongue that heals without treatment. About 20 percent of Americans at any one time experience a canker sore, which are most common between ages 10 and 40. The most severely affected people have almost continuous sores, while others have just one or two per year.
Because hemolytic streptococcus bacteria have so often been isolated from canker sores, experts believe they may be caused by a hypersensitive reaction to the bacteria. Other factors often associated with a ﬂare-up include trauma (such as biting the inside of the cheek), acute stress and allergies, or chemical irritants in toothpaste or mouthwash. More women than men experience canker sores, which are more likely to occur during the premenstrual period and are more likely to occur if other members of the family suffer from them. Interestingly, the older a person gets the less likely they are to suffer a canker sore. Some experts believe canker sores may be connected to an underlying immune system defect similar to an allergy.
A canker sore is usually a small oval ulcer with a gray center surrounded by a red, inﬂamed halo, which usually lasts for one or two weeks. They are similar but not identical to COLD SORES (or “fever blisters)”, which also appear on the mouth. Both usually cause small sores that heal within two weeks. However, canker sores are not usually preceded by a blister. Canker sores are usually larger than fever blisters, but they do not usually merge to form one large sore as fever blisters do. Finally, canker sores usually erupt on movable parts of the mouth (such as the tongue and the cheek or lip linings), whereas cold sores usually appear on the gums, roof of the mouth, lips, or nostrils.
While the ulcers will heal themselves, topical painkillers may ease the pain; healing may be speeded up by using a corticosteroid ointment or a tetracycline mouthwash. Victims may also cover the sore with a waterproof ointment to protect it. A canker sore should heal within two weeks; if it persists, or if the sufferer cannot eat, speak, or sleep, seek medical help.
Over-the-counter medication containing carbamide peroxide (Cankaid, Glyoxide, and Amosan) may be effective in treating the sore. Other possibilities include medications that include liquid or gel forms of benzocaine, menthol, camphor, eucalyptol and/or alcohol, or pastes (such as Orabase) that form a protective “bandage” over the sore. For short-term pain relief, rinse with a prescription mouthwash containing viscous lidocaine, an anesthetic.
Children prone to canker sores should avoid coffee, spices, citrus fruits, walnuts, strawberries, and chocolates. Instead, eating at least four tablespoons of plain yogurt containing Lactobacillus acidophilus daily introduces helpful bacteria into the mouth to ﬁght canker sore bacteria. To prevent outbreaks and to heal severe ones, a prescription anti-inﬂammatory steroid may help.
Children should avoid commercial toothpastes and mouthwashes and brush teeth with baking soda for a month or two. The mouth should be rinsed with warm salt water. Speciﬁcally, scientists found that toothpaste with the detergent sodium lauryl sulfate (SLS) was linked to canker sores in susceptible children. In a study of 10 people prone to sores, brushing with SLS-free paste for three months led to a 70 percent decrease in the number of canker sores. Scientists suggest that SLS may dry out the mucous layer of the mouth, leaving gums and cheeks vulnerable to irritants.