From the Guidelines
The most likely cause of mouth ulcers is a combination of local and systemic factors, including minor trauma, stress, hormonal changes, nutritional deficiencies, and underlying health conditions such as celiac disease, inflammatory bowel disease, or autoimmune disorders. According to the expert consensus guideline for diagnosis of difficult and complicated oral ulceration 1, oral ulcers can be caused by a variety of factors, including traumatic, infectious, allergic factors, and may be associated with skin disease, autoimmune disease, tumor, inflammatory bowel disease, and so on.
Some common causes of mouth ulcers include:
- Minor trauma to the mouth's soft tissues, such as accidental biting of the cheek, tongue, or lip, or injury from hard foods, dental appliances, or aggressive tooth brushing
- Stress, hormonal changes, nutritional deficiencies (particularly vitamin B12, folate, iron, and zinc)
- Certain foods (like citrus fruits, coffee, chocolate, and spicy foods)
- Underlying health conditions such as celiac disease, inflammatory bowel disease, or autoimmune disorders
Treatment typically involves over-the-counter topical medications containing benzocaine (such as Orajel) or hydrogen peroxide (like Peroxyl) to relieve pain, or antimicrobial mouthwashes containing chlorhexidine to prevent infection 1. For pain relief, taking acetaminophen or ibuprofen can help. Most mouth ulcers heal on their own within 1-2 weeks without treatment. To prevent recurrence, maintain good oral hygiene, use a soft-bristled toothbrush, avoid triggering foods, and manage stress effectively. If ulcers are large (greater than 1 cm), extremely painful, last longer than three weeks, or occur frequently, medical evaluation is recommended as they may indicate a more serious underlying condition, such as Crohn’s disease 1 or oral tuberculosis 1.
From the Research
Causes of Mouth Ulcers
The most likely cause of mouth ulcers can be attributed to various factors, including:
- Trauma and infections, which can result in innocent solitary ulcerations 2
- Immune system disturbances, such as erosive lichen planus, mucous membrane pemphigoid, and pemphigus vulgaris, which can cause multiple chronic oral ulcers 2
- Recurrent aphthous ulcers, also known as canker sores, which are a common type of inflammatory efflorescence of the oral mucosa 3
- Infections, such as acute necrotizing ulcerative gingivitis, and allergies, which can cause rapid-onset oral ulcers 2
- Systemic diseases, such as Adamantiades-Behçet disease, which can cause severe and refractory oral aphthous ulcers 3
Factors that Can Trigger or Exacerbate Mouth Ulcers
Certain factors can trigger or exacerbate mouth ulcers, including:
- Hard, acidic, and salty foods 3
- Toothpastes containing sodium lauryl sulfate 3
- Alcohol and carbonated drinks 3
- Trauma, such as biting the cheek or tongue 2
- Systemic diseases, such as autoimmune disorders 4
Importance of Diagnosis and Treatment
Diagnosis and treatment of mouth ulcers are crucial to relieve pain, lessen functional impairment, and lower the frequency and severity of recurrences 3. A detailed patient history and clinical examination are essential in assessing ulcerative oral lesions, and biopsy may be indicated in many cases to establish a diagnosis 4.