What is the etiology of recurrent oral ulcers (mouth ulcers)?

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Last updated: April 27, 2025View editorial policy

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From the Guidelines

Recurrent oral ulcers are primarily caused by a combination of local and systemic factors, including traumatic, infectious, allergic factors, and may be associated with skin disease, autoimmune disease, tumor, inflammatory bowel disease, and so on, as stated in the expert consensus guideline for diagnosis published in the International Journal of Oral Science in 2022 1. The etiology of recurrent oral ulcers is complex and diverse, making diagnosis and treatment challenging for oral specialists. According to the study published in 2022 1, oral ulceration can be attributed to local stimulus, including mechanical, physical, or chemical factors, as well as systemic causes. The exact cause of recurrent aphthous ulcers (RAU) is unknown, but it may be caused by disturbed immune response, genetic predisposition, nutrient deficiency, oral trauma, anxiety, or stress. Some key points to consider in the etiology of recurrent oral ulcers include:

  • Traumatic factors, such as minor trauma from dental appliances or aggressive brushing
  • Systemic conditions, such as Behçet's disease, celiac disease, inflammatory bowel disease, HIV infection, and cyclic neutropenia
  • Nutritional deficiencies, especially of vitamin B12, folate, iron, and zinc
  • Genetic factors, with family history being a risk factor
  • Immune system dysfunction, with T-cell mediated responses and altered cytokine production leading to mucosal damage It is essential to identify and address these underlying factors to effectively manage recurrent oral ulcers, as stated in the expert consensus guideline for diagnosis published in the International Journal of Oral Science in 2022 1.

From the Research

Etiology of Recurrent Oral Ulcer

  • The cause of recurrent oral ulcers is idiopathic in most patients, with local trauma and stress being the most likely precipitating factors 2
  • Other associated factors include systemic diseases, nutritional deficiencies, food allergies, genetic predisposition, immune disorders, the use of certain medications, and HIV infection 2
  • Hard, acidic, and salty foods, as well as toothpastes containing sodium lauryl sulfate, should be avoided as they can trigger or exacerbate oral ulcers 3
  • Recurrent oral ulcerations can be manifestations of a heterogeneous set of both general and more-or-less specific oral diseases due to numerous potential etiologies, including infections, medications, autoimmune disease, and other systemic disease 4

Classification of Recurrent Oral Ulcer

  • Recurrent oral ulcers can be classified into different types, including traumatic ulceration, chemical ulceration, recurrent aphthous stomatitis, medication-related ulceration, infectious ulceration, mucocutaneous disease, and autoimmune/systemic disease 4
  • Recurrent aphthous stomatitis (RAS) is the most frequent form of oral ulceration, characterized by recurrent oral mucosal ulceration in an otherwise healthy individual 5

Management of Recurrent Oral Ulcer

  • The primary goals of therapy for recurrent oral ulcers are relief of pain, reduction of ulcer duration, and restoration of normal oral function 2
  • Topical medications, such as antimicrobial mouthwashes and topical corticosteroids, can achieve the primary goals but have not been shown to alter recurrence or remission rates 2
  • Systemic medications can be tried if topical therapy is ineffective, with options including levamisole, oral corticosteroids, and thalidomide 2
  • A diagnostic algorithm for recurrent oral ulceration can be used to guide management and treatment 4

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Treatment strategies for recurrent oral aphthous ulcers.

American journal of health-system pharmacy : AJHP : official journal of the American Society of Health-System Pharmacists, 2001

Research

The treatment of chronic recurrent oral aphthous ulcers.

Deutsches Arzteblatt international, 2014

Research

Systemic interventions for recurrent aphthous stomatitis (mouth ulcers).

The Cochrane database of systematic reviews, 2012

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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