Medically known as aphtous ulcers, these nuisance, small lesions on the inside of your mouth or at the base of the gums, are a medical mystery in its own right. We don’t know how and why they appear. Mystery. Medicine doesn’t have all the answers, after all.
The work canker means “spreading ulcer” and it was the common word for the disease that we all now as cancer until 1700 and in time its meaning shifted to become a general term for ulceration.
They are very common. In fact, they are so common, that nobody is keeping track of its epidemiology, and when researched, all you can get is a wide range of percentages, like 5-70% incidence rate in Canada.
Despite many studies trying to identify a causal microorganism, canker sores do not appear to be infectious, contagious, or sexually transmitted. Immune mechanisms appear at play in persons with a genetic predisposition to oral ulceration. It appears that they are the result of a T cell–mediated response to the antigens of Streptococcus sanguis, a nasty bacterium.
People often confuse them with the Cold sores, which are completely different. Cold sores, also called fever blisters or herpes simplex (HPV) type 1, are groups of painful, fluid-filled blisters. Unlike canker sores, cold sores are caused by a virus and are extremely contagious. Also, cold sores typically appear outside the mouth – usually under the nose, around the lips, or under the chin – while canker sores occur inside the mouth.
What triggers these pesky things on the inside of your mouth?
Stress or tissue injury is thought to be the cause of simple canker sores. Certain foods, some people reported citrus or acidic fruits and vegetables (such as lemons, oranges, pineapples, apples, figs, tomatoes, and strawberries), can trigger a canker sore or make the problem worse. Sometimes a sharp tooth surface or dental appliance, such as braces or ill-fitting dentures, might also trigger canker sores.
In the matter of how you treat them, and because we don’t know what exactly cause them, medicine doesn’t have much to offer. Conventional medicine says Just pay attention to the triggers and avoid them. Complementary medicine will offer you coconut oil, sage or honey rub, cayenne cream, aloe rinse, gargle with warm salt water etc. With or without treatment, the pain lessens after 2-3 days and the canker sores will heal in 7-10 days anyway.
So, to answer to the question from the title, canker sores are not contagious (if you were afraid of that) and they will spontaneous heal in 7-10 days. The miracles and mysteries of the human body.