Aphthous Ulcer

Aphthous ulcers, commonly called canker sores, are painful mouth sores that affect about one in five people at some point in their lives. These small ulcers appear inside the mouth and, while usually harmless, can make eating and talking difficult until they heal.

Table of contents

• Identification and Alternative Names
• What Are Aphthous Ulcers?
• Who Gets Aphthous Ulcers?
• Types of Aphthous Ulcers
• Symptoms and Appearance
• Causes and Triggers
• Diagnosis
• Related Health Conditions
• Treatment Options
• Prevention
• Outlook

Identification and Alternative Names

Aphthae, Aphthosis, Aphthous stomatitis, Canker sore

K12.0; N76.6; N50.8; N77.0

• Oral mucosa (mouth lining)
• Lips (inner surface)
• Cheeks (inner surface)
• Tongue
• Gums
• Soft palate
• Genital mucosa

What Are Aphthous Ulcers?

An aphthous ulcer is the most common type of ulcer that forms inside the mouth. It appears as a painful, punched-out sore on the delicate tissue that lines the inside of the mouth, known as the mucous membrane^[1]. These ulcers can occur on various soft surfaces inside the mouth, including the inside of the lips and cheeks, under the tongue, and on the gums^[2].

Aphthous ulcers are not contagious and cannot be spread through saliva or contact with another person^[3]. This distinguishes them from cold sores, which are caused by a virus and can spread from person to person. Aphthous ulcers occur only inside the mouth, while cold sores typically appear on the outer surface of the lips^[5].

In most cases, these ulcers are harmless and heal on their own within 10 to 14 days without leaving scars^[1]. However, they can cause significant discomfort, particularly when eating, drinking, or talking.

Who Gets Aphthous Ulcers?

Aphthous ulcers are very common, affecting approximately 20 to 25 percent of the population^[1]. Anyone can develop these ulcers, though they typically first appear during childhood or adolescence^[1]. They are most common in teenagers and people in their 20s^[3].

Women are more likely to experience aphthous ulcers than men^[1]. Researchers believe this difference may be related to hormonal factors^[3]. About 40 percent of people who get aphthous ulcers have a family history of the condition, suggesting that genetics may play a role^[1].

Interestingly, people who smoke tobacco may be less likely to develop aphthous ulcers, even though smoking worsens many other mouth and skin conditions^[1]. It is unusual for someone to develop their first aphthous ulcer after age 40^[3].

Types of Aphthous Ulcers

Aphthous ulcers are classified into three main types based on their size, appearance, and how long they take to heal^[2].

Minor aphthous ulcers are the most common type, accounting for about 80 percent of all cases^[1]. These ulcers are small, usually less than 5 millimeters in diameter (about the size of a pencil eraser or smaller). They typically appear as round or oval sores and heal within one to two weeks without leaving scars^[2]. A person may have one ulcer or several at the same time, and they can recur at intervals of one to four months^[4].

Major aphthous ulcers are larger and more severe. They are typically more than 10 millimeters in diameter and involve deeper layers of tissue^[1]. These ulcers are extremely painful and can take anywhere from two weeks to several months to heal. Unlike minor ulcers, major aphthous ulcers often leave scars after healing^[2]. They can affect any area of the mouth, including deeper areas like the throat^[4].

Herpetiform ulcers are the least common type, affecting only about 1 to 10 percent of people with aphthous ulcers^[4]. Despite their name, these ulcers are not caused by the herpes virus. They appear as multiple small, pinpoint ulcers (2 to 3 millimeters in diameter) that can cluster together, sometimes numbering up to 100 at once^[4]. The clusters may merge to form larger, irregular-shaped ulcers. These typically heal within one to two weeks and may leave scars^[2].

Symptoms and Appearance

Before an aphthous ulcer appears, many people experience a warning sign. About two to 48 hours before the ulcer forms, you may notice a tingling, burning, or itching sensation in the area where the ulcer will develop^[3].

When the ulcer first develops, it typically appears as a round yellowish elevated spot surrounded by a red ring or halo^[1]. As it progresses, it breaks down into a clearly defined, punched-out sore. The center of the ulcer is covered with a white, yellow, or grayish membrane, while the surrounding tissue appears red and inflamed^[1]. The tissue around the ulcer remains otherwise healthy and unaffected^[1].

The main symptom of an aphthous ulcer is pain, which can range from mild discomfort to severe pain depending on the size and location of the ulcer^[3]. The pain typically worsens when the ulcer is irritated by movement, eating certain types of food (especially citrus fruits, spicy foods, or salty foods), or brushing teeth^[1].

Aphthous ulcers most commonly appear on soft, movable areas inside the mouth, such as the inside of the lips and cheeks, the sides or underside of the tongue, the floor of the mouth, and the soft palate at the back of the roof of the mouth^[1]. They do not typically occur on tightly bound surfaces like the hard palate or the attached gums around teeth. In some cases, aphthous ulcers can also affect the genitals in both males and females^[1].

Causes and Triggers

The exact cause of aphthous ulcers is not fully understood^[1]. Current scientific thinking suggests that the immune system becomes disturbed by external factors and reacts abnormally against proteins in the mouth’s mucous membrane tissue^[1]. The condition appears to involve problems with cell-mediated immunity, which is the part of the immune system that uses special cells rather than antibodies to fight infections^[7].

Although the underlying cause remains unclear, researchers have identified several factors that can trigger outbreaks of aphthous ulcers^[1]:

• Emotional stress and lack of sleep can trigger ulcer formation
• Physical injury to the mouth, such as accidentally biting the inside of your cheek, scrapes from braces or ill-fitting dental appliances, or aggressive tooth brushing
• Nutritional deficiencies, particularly low levels of vitamin B12, iron, folic acid (folate), or zinc
• Certain foods, including chocolate, coffee, strawberries, eggs, nuts, cheese, and foods that are spicy, acidic, or salty
• Toothpastes and mouthwashes containing sodium lauryl sulfate (the ingredient that creates foam)
• Hormonal changes during menstruation
• Certain medications, including nicorandil (used for chest pain), beta-blockers, immunosuppressants, and nonsteroidal anti-inflammatory drugs (NSAIDs)
• Viral infections

Some people find that keeping a food diary helps them identify which foods trigger their ulcers, allowing them to avoid those foods in the future^[3].

Diagnosis

Aphthous ulcers are usually diagnosed based on their appearance and the patient’s description of symptoms^[1]. Your doctor or dentist can typically identify them through a visual examination of your mouth. No special tests are needed in most cases^[2].

If you have recurrent attacks of multiple or severe ulcers, your healthcare provider may recommend some investigations to look for underlying causes^[1]. These tests may include:

• Blood tests to check for anemia, and levels of iron, vitamin B12, and folate
• Tests for antibodies to gluten (to check for celiac disease)
• Stool tests to check for markers of Crohn’s disease
• Swabs of the ulcers to test for infections such as Candida (yeast), herpes simplex virus, or certain bacteria

Your healthcare provider will want to rule out other conditions that can cause mouth ulcers. Unlike aphthous ulcers, cold sores caused by herpes simplex virus typically occur on or near the lips and are contagious. Other viral infections that can cause mouth sores include hand, foot, and mouth disease and herpangina^[1].

If you have unusually large canker sores, sores that last longer than two weeks, sores that are extremely painful, or frequent recurrences, you should see your doctor or dentist^[2]. An ulcer that does not heal may rarely be a sign of mouth cancer, especially in people who use tobacco products or drink alcohol regularly^[10].

Related Health Conditions

Aphthous ulcers can sometimes be an early sign or symptom of other health conditions. In some cases, these ulcers occur as part of more serious systemic diseases^[1].

Behçet’s disease is an autoimmune condition that causes blood vessel inflammation throughout the body. People with this disease experience recurrent mouth ulcers along with ulcers on the genitals, eye inflammation (uveitis), and vision problems (retinitis)^[8].

Gastrointestinal disorders can be associated with aphthous ulcers. These include celiac disease (an immune reaction to eating gluten), Crohn’s disease (inflammation of the digestive tract), and ulcerative colitis (inflammation and ulcers in the colon)^[1].

In children, aphthous ulcers can be a feature of PFAPA syndrome, which stands for Periodic Fever, Aphthous stomatitis, Pharyngitis, and Adenitis. This is a recurrent fever syndrome that causes episodes of fever along with mouth ulcers, sore throat, and swollen lymph nodes^[1].

People with weakened immune systems, such as those with HIV/AIDS, may develop larger, more severe, or more persistent aphthous ulcers^[3]. Certain immune-related conditions like lupus erythematosus, bullous pemphigoid, and pemphigus vulgaris can also cause mouth ulcers that may be confused with aphthous ulcers^[8].

Treatment Options

Most minor aphthous ulcers heal on their own within one to two weeks without treatment^[2]. However, various treatments are available to help relieve pain, speed healing, and reduce the frequency of recurrences.

Mouth rinses can help reduce pain and prevent infection. Regular antimicrobial mouthwash containing chlorhexidine can help prevent germs from spreading and worsening the ulcer^[1]. However, you should avoid mouthwashes that contain alcohol, as these can irritate the sore^[3]. For multiple canker sores, doctors may prescribe a mouth rinse containing dexamethasone (a steroid that reduces inflammation) or lidocaine (a numbing medication)^[18].

Over-the-counter topical products come as gels, creams, pastes, or liquids that you apply directly to the ulcer. These products may contain active ingredients such as benzocaine or lidocaine to numb the area and reduce pain, or fluocinonide (a steroid) to reduce inflammation^[18]. Applying these products as soon as you notice an ulcer forming can help speed healing^[18].

Prescription corticosteroid treatments are the main medical treatment for aphthous ulcers^[7]. These come in various forms, including hydrocortisone pellets that dissolve in the mouth, triamcinolone paste, and betamethasone mouth rinse^[14]. Corticosteroids help reduce pain and inflammation, though they may not prevent new ulcers from forming^[14].

Other topical medications that may help include amlexanox paste, which has been found to shorten healing time for minor ulcers^[14]. Some healthcare providers recommend applying alum powder (potassium aluminum sulfate), which has properties that may help shrink tissues and dry out the ulcer^[21].

Laser therapy has emerged as an effective treatment option. Low-level laser therapy uses light energy to promote healing, reduce the size of ulcers, and relieve symptoms without causing heat damage to tissues^[4].

Probiotics show promise for long-term management. Using probiotics as mouthwash or tablets may help extend the time between episodes and reduce how often ulcers recur^[4].

Systemic medications may be needed for severe or frequent ulcers that do not respond to topical treatments. These can include oral medications such as colchicine (normally used for gout), pentoxifylline, or prednisolone (an oral steroid)^[1]. For particularly severe cases related to conditions like Behçet’s disease, stronger immunosuppressive drugs may be necessary^[1].

Nutritional supplements may be recommended if blood tests reveal deficiencies in iron, vitamin B12, folate, or other nutrients^[14]. Correcting these deficiencies can help reduce the frequency and severity of ulcers.

Prevention

While there is no guaranteed way to prevent aphthous ulcers, several strategies may help reduce their frequency and severity^[3].

Practice good oral hygiene by brushing your teeth gently with a soft-bristled toothbrush after meals and using waxed dental floss^[3]. Brush carefully to avoid injuring the delicate tissues inside your mouth. Consider switching to a toothpaste that does not contain sodium lauryl sulfate, as this ingredient may trigger ulcers in some people^[1].

Avoid foods and drinks that trigger your ulcers. Common triggers include acidic foods (like citrus fruits and tomatoes), spicy foods, salty foods, hard or sharp foods (like toast or potato chips), chocolate, coffee, nuts, cheese, eggs, strawberries, and carbonated drinks^[1]. Keep a food diary to help identify your personal triggers.

Take steps to reduce stress and ensure you get enough sleep, as both stress and fatigue can trigger ulcers^[1]. Practice stress-reduction techniques such as meditation or deep breathing exercises^[3].

Protect your mouth from injury. Be careful when eating to avoid accidentally biting the inside of your cheek or tongue. If you have braces or other dental appliances that have sharp edges, ask your dentist about orthodontic wax to cover these areas^[3]. Make sure dentures or other dental devices fit properly.

Talk to your healthcare provider about potential nutritional deficiencies, as addressing low levels of vitamins and minerals may help prevent recurrences^[3]. If certain medications seem to trigger your ulcers, discuss alternatives with your doctor.

Outlook

The outlook for people with aphthous ulcers is generally good. Most ulcers heal completely within one to two weeks without leaving scars, and they do not cause lasting damage^[3]. Even major aphthous ulcers, though they take longer to heal and may leave scars, eventually resolve on their own or with treatment.

For many people, aphthous ulcers tend to appear most frequently during the teenage years and twenties, then gradually decrease in frequency over time^[6]. The natural course of recurrent aphthous ulcers is one of eventual remission, with many people experiencing fewer and less severe outbreaks as they get older^[14].

While recurrences are common, understanding your triggers and following preventive measures can help reduce how often ulcers appear and how severe they are when they do occur. With appropriate management, most people with aphthous ulcers can minimize the impact these sores have on their daily lives.