Canker Sores (Aphthous Ulcer) Causes, Symptoms, Diagnosis, Treatment, Prevention, Home Remedies

Canker Sores (Aphthous Ulcer) Causes, Symptoms, Diagnosis, Treatment, Prevention, Home Remedies


What are canker sores?


Canker sores, also called aphthous ulcers, are small, shallow lesions that develop on the soft tissues in your mouth or at the base of your gums. Unlike cold sores, canker sores don't occur on the surface of your lips and aren't contagious. They can be painful, however, and can make eating and talking difficult.

Canker Sores (Aphthous Ulcer)



Canker sores are the most common type of oral lesion, affecting about 20% of people. Women get canker sores more often than men. Canker sore susceptibility may be inherited, and the condition can run in families.



Most canker sores go away on their own in a week or two. Check with your doctor or dentist if you have unusually large or painful canker sores or canker sores that don't seem to heal.

What Causes Canker Sores (Aphthous Ulcer)?


The exact cause of most canker sores is unknown. Stress or tissue injury is thought to be the cause of simple canker sores. Certain foods -- including 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.

Some cases of complex canker sores are caused by an underlying health condition, such as an impaired immune system; nutritional problems, such as vitamin B-12, zinc, folic acid, or iron deficiency; and gastrointestinal tract disease, such as Celiac disease and Crohn's disease.

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Are cold sores the same thing as Canker Sores (Aphthous Ulcer)?


No. Although these sores are often confused for each other, they are not the same. Cold sores, also called fever blisters or herpes simplex 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 are symptoms of Canker Sores (Aphthous Ulcer)?


Canker sores are painful sores inside the mouth. They may occur on the tongue, the lining of the cheeks, the gums, the inside of the lips, or the soft palate on the back of the roof of your mouth. Common symptoms of canker sores include:

  • A burning, tingling, or prickling sensation, up to 24 hours before the sore appears
  • Crater-like ulcers that are white, gray, or yellow in color, with a red border
  • Sores are usually painful
  • Difficulty speaking, eating, or swallowing
Less common symptoms that can also indicate a more serious underlying infection include:

  • Fever
  • Swollen lymph nodes
  • Sluggishness

When to see a doctor


Consult your doctor if you experience:

  • Unusually large canker sores
  • Recurring sores, with new ones developing before old ones heal
  • Persistent sores, lasting three weeks or more
  • Sores that extend into the lips themselves (vermilion border)
  • Pain that you can't control with self-care measures
  • Extreme difficulty eating or drinking
  • High fever along with canker sores
See your dentist if you have sharp tooth surfaces or dental appliances that seem to trigger the sores.

Diagnosis for Canker Sores (Aphthous Ulcer)


Tests aren't needed to diagnose canker sores. Your doctor or dentist can identify them with a visual exam. In some cases, you may have tests to check for other health problems, especially if your canker sores are severe and ongoing.

How are Canker Sores (Aphthous Ulcer) treated?


Treatment usually isn't necessary for minor canker sores, which tend to clear on their own in a week or two. But large, persistent or unusually painful sores often need medical care. A number of treatment options exist, ranging from mouth rinses and topical ointments to systemic corticosteroids for the most-severe cases.

Mouth rinses


If you have several canker sores, your doctor may prescribe a mouth rinse containing the steroid dexamethasone (dek-suh-METH-uh-sown) to reduce pain and inflammation. Oral suspensions of the antibiotic tetracycline also can reduce pain and cut healing time, but tetracycline has drawbacks. It can make you more susceptible to oral thrush, a fungal infection that causes painful mouth sores, and it can permanently discolor children's teeth.

Topical pastes


Over-the-counter and prescription pastes with active ingredients such as benzocaine (Anbesol), amlexanox (Aphthasol) and fluocinonide (Lidex, Vanos) can help relieve pain and speed healing if applied to individual sores as soon as they appear. Your doctor may recommend applying the paste to the sore two to four times a day until it heals.

Oral medications


Medications not intended specifically for canker sore treatment, such as the heartburn drug cimetidine (Tagamet) and colchicine, which is normally used to treat gout, may be helpful for canker sores. Your doctor may prescribe oral steroid medications when severe canker sores don't respond to other treatments, but because of serious side effects, they're usually considered a last resort.

Cautery of sores


During cautery, an instrument or chemical substance is used to burn, sear or destroy tissue. Debacterol is a topical solution designed to treat canker sores and gum problems. By chemically cauterizing canker sores, this medication may reduce healing time to about a week. Silver nitrate — another option for chemical cautery of canker sores — hasn't been shown to speed healing, but it may help relieve canker sore pain.

Nutritional supplements


Your doctor may prescribe a nutritional supplement if you consume low amounts of important nutrients, such as folate (folic acid), vitamin B-6, vitamin B-12 or zinc.

If your canker sores relate to a more serious health problem, your doctor will treat the underlying condition.

Can mouthwash solutions be used to treat Canker Sores (Aphthous Ulcer)?


There are several mouthwash solutions that may be used to treat canker sore symptoms.

  • Diphenhydramine suspension (Benadryl Allergy liquid) is available over-the-counter and can be used as a mouth rinse because it has topical anesthetic effects on the tissue of the mouth and the canker sore. Put the suspension in your mouth, swish it around for 30 seconds to one minute, and spit it out. Do not swallow the rinse.
  • Anti-inflammatory steroid mouth rinses may be prescribed by your doctor or dentist to help reduce inflammation.
  • Tetracycline antibiotic rinses may be prescribed, and have been shown to relieve the pain and promote healing of canker sores. Tetracycline should not be used by pregnant women, people allergic to tetracycline, or children under 16.

Can Canker Sores (Aphthous Ulcer) Be Prevented?


Canker sores often recur, but you may be able to reduce their frequency by following these tips:

Follow good oral hygiene habits. Regular brushing after meals and flossing once a day can keep your mouth clean and free of foods that might trigger a sore. Use a soft brush to help prevent irritation to delicate mouth tissues, and avoid toothpastes and mouth rinses that contain sodium lauryl sulfate.

Avoiding foods that irritate your mouth, including citrus fruits and acidic vegetables and spicy foods.

Choose healthy foods. To help prevent nutritional deficiencies, eat plenty of fruits, vegetables and whole grains.

Avoiding irritation from gum chewing.

Brushing with a soft-bristled brush after meals and flossing daily, which will keep your mouth free of foods that might trigger a sore.

Protect your mouth. If you have braces or other dental appliances, ask your dentist about orthodontic waxes to cover sharp edges.

Reduce your stress. If your canker sores seem to be related to stress, learn and use stress-reduction techniques, such as meditation and guided imagery.

Home remedies for Canker Sores (Aphthous Ulcer)


Brush your teeth gently, using a soft brush and toothpaste without foaming agents.

Rinse your mouth. Use salt water; baking soda (dissolve 1 teaspoon of soda in 1/2 cup warm water); or a mixture of 1 part — such as 1 teaspoon — diphenhydramine (Benadryl) to either 1 part Kaopectate or 1 part Maalox. Be sure to spit out the mixtures after rinsing.

Avoid abrasive, acidic or spicy foods that can cause further irritation and pain.

Dab a small amount of milk of magnesia on your canker sore a few times a day.

Try over-the-counter products that contain the numbing agent benzocaine.

Cover canker sores with a paste made of baking soda plus a small amount of water — just enough to make a paste.