Cause Remains a Mystery : Cold, Dry Days Can Bring Outbreak of Canker Sores

When the days are cold and dry and the nose is stuffy, then mouth sores become an increasingly common problem.

“Your mouth is dryer and there is an abnormal balance of bacteria in your saliva,” said Dr. Jeffrey Kerner, president of the Long Island branch of the American Academy of Otolaryngology--Head and Neck Surgery. “For people prone to these sores, the colder months can mean a lot more outbreaks.”

Doctors have little idea what causes aphthous ulcers, commonly known as canker sores. Because the problem is so common and rarely troublesome, few researchers have spent time studying its causes and cures.

According to a report from the academy, the sores can appear on the inside of the lips, gums and tongue. They can be as small as a pinprick or involve the entire interior of the cheek. And they can range from unnoticeable to painfully irritating.

Some People Susceptible

Doctors said some people are prone to canker sores and others are not.

“There are people who have never had one,” Kerner said. “And then there are people who get them all the time.”

Some researchers believe a virus may cause the sores--and believe that simply because there is no better explanation. Almost everyone must have been exposed to the virus at one time or another, they theorize, and some people are susceptible to it while others are not.

But even if canker sores are caused by a virus, they are not transmitted through kissing or sharing utensils used in eating and drinking, according to the academy.

Not Like Herpes Virus

“In that way it is very different from the herpes simplex 1 virus, which is very contagious during some periods of time,” Kerner said. The herpes virus causes fever blisters, or cold sores, on the lips.

“Commonly canker sores are found on the inside of the mouth and cold sores on the parts of the lip where the skin meets a mucous membrane,” he said.

The academy reports that some doctors believe emotional or psychological stress, minor injuries and an intolerance to some types of food can contribute to a canker sore outbreak.

The sores usually take several days to develop and remain for about a week before fading away, the report said.

Foods to Avoid

The group advises people who are prone to canker sores to avoid excessively sugary foods as well as chocolate, nuts, coconut and peanut butter, all of which appear to aggravate the condition.

Acidic foods such as grapes, plums, citrus fruit and tomatoes can make the sores more painful when they do appear.

Kerner said folk remedies abound when it comes to canker sores. Some people find relief by sucking on antacid tablets, which decrease acid levels in the saliva of the mouth.

Others say rinsing their mouths out with warm salt water or solutions containing diluted peroxide helps ease the pain and quicken the healing process.

Antibiotic Developed

Recently, drug companies have developed antibiotics that can be applied to a wet surface. The drugs come in gels that can numb the sore and prevent secondary infections, but doctors said such drugs are needed only by people with particularly painful or frequent sores.

“In my years of practice I’ve found very, very few patients who have complained about canker sores,” said Kerner, who practices in Long Beach on New York’s Long Island. “For most people, it’s just an annoying little fact of life.”

Cold sores, on the other hand, can be painful and, for some people, embarrassing, doctors say.

“The virus, which infects most people before adulthood, usually lies dormant in the nerves of the lips until reactivated by a variety of causes,” according to another academy report. “Factors causing flare-ups include a high fever, a cold, exposure to too much sun and emotional stress.”

Kerner said cold sores rarely occur on the inside of the mouth. But when they do, they have the characteristic blister type appearance as when they appear on the outside of the lips.