Definition

Canker sores are small sores or ulcers that appear inside
the mouth. They are painful, self-healing, and can recur.

Description

Canker sores occur on the inside of the mouth, usually
on the inside of the lips, cheeks, and/or soft palate.
They can also occur on the tongue and in the throat.
Often, several canker sores will appear at the same time
and may be grouped in clusters. Canker sores appear as a
whitish, round area with a red border. The sores are
painful and sensitive to touch. The average canker sore is
about one-quarter inch in size, although they can occasionally
be larger. Canker sores are not infectious.

Approximately 20% of the U.S. population is affected
with recurring canker sores, and more women than
men get them. Women are more likely to have canker
sores during their premenstrual period.

Canker sores are sometimes confused with cold
sores. Cold sores are caused by herpes simplex virus.
This disease, also known as oral herpes or fever blisters,
can occur anywhere on the body. Most commonly, herpes
infection occurs on the outside of the lips and the
gums, and much less frequently on the inside the mouth.
Cold sores are infectious.

Causes and symptoms

The exact cause of canker sores is uncertain, however,
they seem to be related to a localized immune reaction.
Other proposed causes for this disease are trauma to
the affected areas from toothbrush scrapes, stress, hormones,
and food allergies. Canker sores tend to appear
in response to stress. The initial symptom is a tingling or
mildly painful itching sensation in the area where the
sore will appear. After one to several days, a small red
swelling appears. The sore is round, and is a whitish
color with a grayish colored center. Usually, there is a red
ring of inflammation surrounding the sore. The main
symptom is pain. Canker sores can be very painful, especially
if they are touched repeatedly, e.g., by the tongue.

They last for one to two weeks.

Diagnosis

Canker sores are diagnosed by observation of the
blister. A distinction between canker sores and cold sores
must be made because cold sores are infectious and the
herpes infection can be transmitted to other people. The
two sores can usually be distinguished visually and there
are specific diagnostic tests for herpes infection.

Treatment

Since canker sores heal by themselves, treatment is
not usually necessary. Pain relief remedies, such as topical
anesthetics, may be used to reduce the pain of the
sores. The use of corticosteroid ointments sometimes
speeds healing. Avoidance of spicy or acidic foods can
help reduce the pain associated with canker sores.

Alternative treatment

Alternative therapies for canker sores are aimed at
healing existing sores and preventing their recurrence.
Several herbal remedies, including calendula (Calendula
officinalis), myrrh (Commiphora molmol), and goldenseal
(Hydrastis canadensis), may be helpful in the
treatment of existing sores. Compresses soaked in teas
made from these herbs are applied directly to the sores.
The tannic acid in a tea bag can also help dry up the sores
when the wet tea bag is used as a compress. Taking dandelion
(Taraxacum officinale) tea or capsules may help
heal sores and also prevent future outbreaks. Since
canker sores are often brought on by stress, such stressrelieving
techniques as meditation, guided imagery,
and certain acupressure exercises may help prevent
canker sores or lessen their severity.

Prognosis

There is no cure for canker sores. They do not get
larger or occur more frequently with age.