OVERVIEW

What is recurrent aphthous ulcer?

Recurrent aphthous ulcer is a type of oral ulcer that recurs frequently, accompanied by a distinct burning pain. It presents as "yellow, red, sunken, and painful." The exact cause and pathogenesis of this condition remain unclear, but it may be related to immune factors, genetic factors, systemic diseases, infections, psychological factors, and environmental factors—though it is not associated with "excessive internal heat" (a concept in traditional Chinese medicine).

Due to the unknown cause, treatment outcomes are often unsatisfactory, and the condition tends to recur, significantly affecting patients' oral health and quality of life. Current treatments focus on alleviating symptoms, prolonging remission periods, and shortening active phases, but a complete cure is not yet possible^[1,2].

Is recurrent aphthous ulcer common?

Recurrent aphthous ulcer is the most common type of oral mucosal ulcer disease. Epidemiological surveys in China indicate a prevalence rate of 10%–25%, meaning 10 to 25 out of every 100 people suffer from this condition. Women are generally more affected than men, and it is most common among individuals aged 10–30^[1].

What are the types of recurrent aphthous ulcer?

The symptoms of recurrent aphthous ulcer vary in severity and are often classified into three types: minor, major, and herpetiform ulcers.

1. Minor: The most common type, accounting for 75%–85% of cases. The number of ulcers is small, usually 3–5 (fewer than 10). The ulcers are small (less than 1 cm), well-defined, and accompanied by noticeable burning pain.
2. Major: One or multiple ulcers may appear. The ulcers are large and deep, often surrounded by red and swollen tissue, with a diameter typically exceeding 1 cm. The pain is severe, and scarring may occur after healing.
3. Herpetiform: Numerous ulcers (more than 10) appear during an episode. The ulcers are small (mostly under 5 mm) and scattered across any part of the mouth, resembling "stars in the sky." Sometimes, adjacent ulcers may merge into larger patches, and symptoms like fever and headache may occur^[1].

Which department should I visit for recurrent aphthous ulcer?

You may consult the departments of oral mucosal diseases, oral medicine, or general dentistry.

For recurrent aphthous ulcers, the oral mucosal diseases department is the preferred choice for treatment.

Given that most hospitals may not be specialized and lack such detailed divisions, you can also visit departments like oral medicine or general dentistry to seek help from dentists experienced in treating oral mucosal diseases.

SYMPTOMS

What are the characteristic manifestations of recurrent aphthous ulcers?

Recurrent aphthous ulcers often occur on non-keratinized or poorly keratinized mucosa, such as the lips, tongue, cheeks, and soft palate, and are usually less than 5 mm in size. The ulcers have very typical features, which can be summarized in four words: yellow, red, sunken, and painful^[3].

1. Yellow: The ulcer surface is covered with a yellow pseudomembrane;
2. Red: A red hyperemic ring surrounds the ulcer;
3. Sunken: The center of the ulcer is slightly depressed;
4. Painful: The ulcer can cause significant burning pain.

Another characteristic of recurrent aphthous ulcers is their cyclical progression from onset to healing. Even without treatment, most ulcers begin to heal after 5 days and fully resolve within 10–14 days, usually without scarring.

Of course, in addition to the above-mentioned minor recurrent aphthous ulcers (accounting for about 80% of cases), other types of ulcer manifestations should also be noted. For example, major recurrent aphthous ulcers are large and deep, causing severe pain and often leaving scars after healing.

Another type, herpetiform recurrent aphthous ulcers, presents as small, scattered ulcers resembling a "starry sky" distribution on the oral mucosa, sometimes accompanied by systemic symptoms such as headache and low-grade fever^[1].

When these recurrent and severe "oral ulcers" occur, specialized medical attention should be sought.

CAUSES

What factors cause recurrent aphthous ulcers?

Among people with very similar lifestyles, some suffer from repeated oral ulcers, while others never experience them. The exact cause and mechanism of recurrent aphthous ulcers remain unclear, with significant individual differences.

Currently, there are different theories about the occurrence of recurrent aphthous ulcers. The most widely accepted is the "triple-factor theory" of genetics, environment, and immunity—an abnormal immune response triggered by genetic predisposition combined with environmental factors. The following factors may contribute to or promote recurrent ulcers:

1. **Genetic predisposition**: The condition tends to run in families, and those with a family history are more susceptible.
2. **Environmental factors**:
   • **Dietary factors**: Consumption of spicy or irritating foods, frequent intake of rough or hard foods, picky eating, and nutritional imbalances.
   • **Poor lifestyle habits**: Irregular routines, frequent late nights, and insufficient sleep.
   • **Psychological influences**: Major life changes (e.g., divorce, bankruptcy), high stress, anxiety, or tension.
   • **Oral environmental factors**: Poor oral hygiene, residual tooth roots, sharp tooth edges, or ill-fitting dentures causing trauma^[1-3].
3. **Other factors**: Systemic diseases (e.g., gastric ulcers, Crohn's disease), bacterial infections (e.g., Helicobacter pylori, L-form streptococci), and viral infections (e.g., herpes simplex virus, adenovirus)^[1,2].

Are recurrent aphthous ulcers caused by "heatiness"?

Many people attribute oral ulcers to "heatiness" and self-medicate with "heat-clearing" remedies.

In reality, oral ulcers are unrelated to "heatiness." Even from a traditional medicine perspective, oral ulcers cannot be simply summarized as "heatiness." Blindly taking "heat-clearing" medications is not recommended.

Are recurrent aphthous ulcers related to vitamin or micronutrient deficiencies?

Possibly.

The exact cause of recurrent aphthous ulcers (oral ulcers) remains unknown. Some studies suggest that deficiencies in vitamins and minerals, particularly vitamin B₁₂, may be linked to their occurrence. However, the effectiveness of vitamin supplementation in treating the condition remains unclear^[3].

Are recurrent aphthous ulcers related to psychological factors?

For some patients, psychological factors may play a role. Studies have found that the incidence of oral ulcers increases significantly among students before exams. Stress, anxiety, and tension can trigger ulcers^[2].

Are recurrent aphthous ulcers related to poor oral hygiene?

Yes.

Poor oral hygiene and excessive dental calculus may lead to infections, increasing the risk of oral ulcers or prolonging healing time. Therefore, those prone to recurrent ulcers should maintain good oral hygiene^[1,3].

Are recurrent aphthous ulcers hereditary?

There is a genetic tendency. If parents frequently experience oral ulcers, their children may also be more susceptible^[1].

Apart from recurrent aphthous ulcers, are there other conditions that can cause oral ulcers?

Yes.

Recurrent aphthous ulcers are the most common cause of oral ulcers. However, other conditions such as Behçet's disease, eosinophilic ulcer of the oral mucosa, systemic lupus erythematosus, and inflammatory bowel disease can also present with oral ulcers, which may be confused with recurrent aphthous ulcers^[3].

For details, see the "Oral Ulcers" topic.

DIAGNOSIS

How is recurrent aphthous ulcer diagnosed?

1. Physical examination: The symptoms of recurrent aphthous ulcers are relatively typical, presenting as round to oval ulcers with scattered distribution, red edges, and a pale yellow exudate in the center. Combined with the patient's history of recurrent episodes, diagnosis can usually be made based on the typical appearance.
2. Biopsy: For severe or atypical oral ulcer presentations, a biopsy can help rule out other mucosal lesions^[3].

Which diseases are easily confused with recurrent aphthous ulcers?

Recurrent aphthous ulcers are easily confused with cancerous ulcers and tuberculous ulcers.

Major recurrent aphthous ulcers generally occur in young and middle-aged adults, often appearing in the posterior part of the oral cavity. These ulcers are large, deep, and have well-defined edges, with a slightly concave base covered by a light yellow pseudomembrane. Patients may also experience systemic symptoms such as low-grade fever, fatigue, and lymph node swelling and pain (in the ulcer area)^[1].

In contrast, cancerous ulcers are more common in the elderly, frequently occurring on the ventral surface or lateral edges of the tongue or the corners of the mouth. These ulcers have irregular edges, a hard base, and sometimes a cauliflower-like appearance at the bottom. Patients often have poor overall health. Tuberculous ulcers, on the other hand, have a rodent-eaten appearance at the edges and granulation tissue at the base. Patients typically exhibit systemic symptoms of tuberculosis, such as fatigue, fever, and weight loss.

If the ulcer is large, deep, and does not heal for an extended period, prompt medical attention is necessary for a biopsy to confirm the diagnosis. Additionally, if ulcers appear not only on the oral mucosa but also on the skin, genital mucosa, or conjunctiva, Behçet's disease should also be considered for differential diagnosis.

For more information on oral ulcer lesions, refer to the "Oral Ulcers" topic.

TREATMENT

How to Treat Recurrent Aphthous Ulcers?

The treatment of recurrent oral ulcers primarily involves identifying and addressing triggers, followed by topical medications to alleviate symptoms. If these measures fail, oral medications may be considered. The goal of treatment is not to "cure" but to reduce recurrence frequency, prolong remission periods, and alleviate pain while speeding up healing^[1,2].

1. For mild ulcers:
   If the pain is tolerable and the number of ulcers is small (usually one or two), extensive treatment is often unnecessary, as most mild recurrent oral ulcers heal on their own within a relatively short period (1–2 weeks).

   Daily care is sufficient: Maintain oral hygiene during the ulcer phase, rinse frequently, and the pain will gradually subside over time.

2. For severe ulcers:
   If the ulcers are painful, numerous (dozens), or accompanied by headaches, fever, swollen lymph nodes, or if symptom relief is urgently needed, topical medications such as lidocaine gel, compound chlorhexidine mouthwash, or dexamethasone acetate patches may be used.

   For large, deep, and extremely painful ulcers—sometimes accompanied by multiple smaller ulcers—medical attention is recommended. Under a doctor's guidance, cauterizing agents (e.g., silver nitrate) or laser therapy can be used for pain relief and cauterization. Steroid injections (e.g., triamcinolone, dexamethasone) may also be administered locally.

   Additionally, oral medications like corticosteroids (e.g., prednisone) or immunosuppressants (e.g., thalidomide) may be prescribed under medical supervision.

3. For ulcers caused by systemic diseases:
   For conditions like gastric ulcers or ulcerative colitis, treatment of the underlying disease is prioritized. Immunomodulators (e.g., thalidomide) may also be used for regulation.

Medication for recurrent oral ulcers should be determined after a doctor’s evaluation due to potential side effects. Self-medication is strongly discouraged.

Seek prompt medical attention if ulcers persist for over a month, are unusually large/deep, or cause severe pain.

Are Antibiotics Effective for Recurrent Aphthous Ulcers?

The exact cause of recurrent aphthous ulcers remains unclear, but bacterial infection is not a primary trigger. Thus, oral antibiotics are generally unnecessary. Treatment focuses on topical anti-inflammatory, pain-relieving, infection-preventing, and healing-promoting agents. Antibiotics are only considered for severe ulcers with secondary infections^[1].

How Long Does It Take for Recurrent Aphthous Ulcers to Heal?

Typically, minor and herpetiform recurrent aphthous ulcers last 10–14 days, while major ulcers may persist for 1–2 months or longer^[1].

Can Recurrent Aphthous Ulcers Turn Cancerous?

Recurrent aphthous ulcers rarely become cancerous. However, large, deep, or long-lasting ulcers (over 1 month) in the same location carry a risk of malignancy. Vigilance is advised for recurrent ulcers in identical spots^[1].

DIET & LIFESTYLE

What should patients with recurrent aphthous stomatitis pay attention to in daily life?

1. Oral ulcer care: Gently wipe the ulcer surface with a cotton ball soaked in saline before and after sleep daily to maintain cleanliness.
2. Maintain oral hygiene: Rinse regularly with mild saltwater or mouthwash to reduce bacterial growth and infection risks.
3. Balancediet: Ensure nutritional diversity in meals and avoid picky eating.

What dietary precautions should patients with recurrent aphthous ulcers take?

1. Cook with less salt, oil, and high-sodium seasonings; avoid pickled vegetables, meats, hard/rough foods (e.g., fried chicken, nuts), and overly hot dishes to prevent mucosal damage^[1].
2. Replace refined grains with legumes, potatoes, or pumpkin for partial staple intake.
3. Balance meat and vegetables: Prioritize poultry/fish (white meat) over fatty cuts; eggs and milk are key protein sources. Increase fruit/vegetable intake.
4. Vegetarians should consume more beans/bean products for protein.
5. Avoid alcohol.

Is mouthwash beneficial for treating recurrent aphthous ulcers?

While many mouthwashes exist, not all aid ulcer treatment. Chlorhexidine mouthwash (4–5 times daily, 5-minute rinses) is commonly used for relief. Long-term use may cause tongue discoloration or tooth staining, but these effects reverse after discontinuation^[1].

PREVENTION

Can Recurrent Aphthous Ulcers Be Prevented?

For recurrent aphthous ulcers, neither a complete cure nor absolute prevention is possible.

However, the following lifestyle recommendations may have some preventive effects:

1. Maintain oral hygiene: Clean your mouth daily and avoid injuries. If there are damaged teeth or dentures in the mouth, it is recommended to repair or adjust them promptly^[1,3].
2. Stay in a positive mood: Psychological factors are a significant trigger for oral ulcers. Therefore, maintaining a cheerful state of mind through activities like watching movies, listening to music, or exercising can help avoid depressive emotions.
3. Adopt healthy lifestyle habits: Balance work and study with rest, and ensure adequate sleep.
4. Maintain a healthy diet: Avoid picky or unbalanced eating, ensure nutritional balance, and consume more fruits and vegetables.