What Is It?
This disease causes painful, round ulcers to develop on the linings
of the cheeks and lips, the tongue or the base of the gums. The
tendency to develop these ulcers is inherited. Ulcers also can be
associated with other diseases, particularly connective tissue diseases
such as lupus or Behçet's syndrome, which cause symptoms on the eyes
and genitals as well as the mouth. There can be one or many ulcers at
the same time, and they are recurrent, which means they keep returning.
Multiple ulcers are scattered across the lining of the mouth, not
clustered. Most people get one to three of these lesions at each
episode, but a small number of people get more than a dozen ulcers at a
The cause of canker sores is not known, but most theories involve an
immune abnormality. Certain blood diseases, vitamin and mineral
deficiencies, allergies, trauma and Crohn's disease cause similar
ulcers. Canker sores are often confused with cold sores, which are
caused by a herpes virus.
Approximately 17% of the population has recurrent aphthous stomatitis, which is classified into three categories:
- Minor ulcers
are less than 1 centimeter (slightly less then ½inch) in diameter and
do not leave scars. The sores usually heal within two weeks.
- Major ulcers
(also called Sutton's disease) are almost ½ inch or more in diameter,
take longer than minor ulcers to heal and may leave scars.
- Herpetiform ulcers are clusters of dozens of smaller ulcers. This form is rare.
People tend to have two to six ulcers per episode and have several
episodes each year. For most people, canker sores are merely an
annoyance, but some people experience large, painful, frequent sores
that can reach 2 to 4 centimeters in diameter. The ulcers can interfere
with speech and eating and can last for weeks to months, causing
significant pain and disability. When they do heal, they may leave
scars that can make it more difficult to move the tongue and can
destroy oral tissue.
You may feel a burning or tingling sensation in an area of
inflammation before an ulcer appears. An ulcer takes two to three days
to form completely. The sores are round, shallow and symmetric, which
means they are the same on all sides. The are painful. They usually are
found on the inner part of the lips and cheeks and the tongue.
Canker sores are the most common recurring oral ulcers and are
diagnosed mostly by process of elimination. If the ulcers become more
frequent or severe, are accompanied by other symptoms (such as rashes,
joint pain, fevers or diarrhea) or are larger than about ½inch in
diameter, you should visit your dentist or physician. He or she will
try to rule out blood diseases, connective tissue diseases, drug
reactions and skin disorders. A biopsy and blood tests may be required
to rule out other conditions or diseases.
The painful stage lasts 3 to 10 days, and most canker sores disappear within 2 weeks.
There is no way to prevent canker sores.
Treatment focuses on relieving symptoms. Rinsing with a warm-water
solution and eating bland foods can minimize discomfort. Anesthetic
medications or over-the-counter agents that are placed directly on the
sores to coat them also may help.
People with more severe disease may need steroid medications placed
on the lesions. These medications significantly shorten the healing
time of the ulcers and prevent them from becoming larger. Other
possible treatments include placing a medication called
chlortetracycline (Aureomycin) on the sores or injecting steroids into
the sores. In very severe, disabling cases, your dentist may prescribe
When To Call a Professional
Canker sores usually are painful but are not a significant risk to
your health. However, if you have severe, recurring canker sores, or if
they are becoming worse, consult your dentist or physician. He or she
may do tests to look for blood problems such as anemias or deficiencies
of iron, folate or vitamin B12. Some research has shown that canker
sores improve when these deficiencies are treated. Persistent or large
ulcers can also occur as a part of other, more significant, disorders,
including inflammatory bowel disease, connective tissue diseases, drug
allergies, arthritic disorders, inflammatory skin disorders and cancer.
Most canker sores clear up without treatment and do not leave scars, although they usually return.