What conditions lead to an increase in aphthous ulcers (canker sores)?

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From the Guidelines

Aphthous ulcers, also known as canker sores, often increase in frequency due to a combination of local and systemic factors, including stress, oral trauma, nutritional deficiencies, hormonal changes, and underlying health conditions such as celiac disease, inflammatory bowel disease, or Behçet's disease. According to the most recent expert consensus guideline for diagnosis of difficult and complicated oral ulcers 1, the causes of oral ulcers are related to traumatic, infectious, allergic factors, and may be associated with skin disease, autoimmune disease, tumor, inflammatory bowel disease, and so on.

Some of the key factors that contribute to an increase in aphthous ulcers include:

  • Stress and anxiety
  • Oral trauma, such as injuries to the mouth tissue
  • Nutritional deficiencies, particularly vitamin B12, zinc, folate, and iron
  • Hormonal changes during menstruation
  • Certain medications, including NSAIDs and beta-blockers
  • Food sensitivities and allergies
  • Underlying health conditions, such as celiac disease, inflammatory bowel disease, or Behçet's disease
  • Poor oral hygiene and ill-fitting dental appliances
  • Genetic predisposition

To reduce the frequency of canker sores, it is recommended to:

  • Manage stress through relaxation techniques and stress-reducing activities
  • Maintain good oral hygiene, including regular brushing and flossing
  • Avoid triggering foods, such as acidic or spicy foods
  • Use a soft-bristled toothbrush to reduce oral trauma
  • Consider vitamin supplements if deficient, as recommended by the expert consensus guideline 1.

It is also important to note that canker sores can be a symptom of underlying health conditions, such as Behçet's disease, which requires prompt and aggressive treatment to prevent irreversible organ damage, as recommended by the 2018 update of the EULAR recommendations for the management of Behçet's syndrome 1. Therefore, persistent or severe cases of canker sores warrant medical attention to rule out more serious conditions.

From the Research

Conditions Leading to an Increase in Aphthous Ulcers

Several conditions can contribute to the development of aphthous ulcers, including:

  • Immunological factors 2, 3
  • Local trauma 2, 3
  • Smoking 2, 3
  • Stress 2, 3
  • Hormonal state 2, 3
  • Family history 2, 3
  • Food hypersensitivity 2, 3
  • Infection 2, 3
  • Vitamin B12 deficiency 2, 4
  • Folate deficiency 4
  • Vitamin B1, B2, and B6 deficiencies 5
  • Hematologic or oncologic conditions 6
  • Autoimmune disorders 6, 3
  • Human immunodeficiency virus (HIV) 6, 3

Nutritional Deficiencies

Nutritional deficiencies, particularly vitamin B12 and folate, have been linked to an increased risk of developing aphthous ulcers 2, 4.

  • A study found that patients with recurrent aphthous stomatitis had significantly lower daily intake of vitamin B12 and folate compared to a control group 4.
  • Another study suggested that consuming sufficient amounts of these vitamins may be a useful strategy to reduce the number and/or duration of aphthous ulcer episodes 4.
  • Vitamin B1, B2, and B6 deficiencies have also been identified as potential precipitating factors in recurrent aphthous ulceration 5.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Aphthous ulcers and vitamin B12 deficiency.

The Netherlands journal of medicine, 1998

Research

Reduced dietary intake of vitamin B12 and folate in patients with recurrent aphthous stomatitis.

Journal of oral pathology & medicine : official publication of the International Association of Oral Pathologists and the American Academy of Oral Pathology, 2010

Research

Recurrent aphthous ulceration: vitamin B1, B2 and B6 status and response to replacement therapy.

Journal of oral pathology & medicine : official publication of the International Association of Oral Pathologists and the American Academy of Oral Pathology, 1991

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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