What is the treatment for a canker sore (aphthous ulcer)?

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Last updated: June 13, 2025View editorial policy

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From the Guidelines

Canker sores can be effectively treated with topical corticosteroids, such as clobetasol propionate 0.05%, applied directly to the affected area daily during the acute phase. This approach is supported by the U.K. guidelines for the management of Stevens-Johnson syndrome/toxic epidermal necrolysis in adults 2016 1. For mild cases, a topical anaesthetic preparation, e.g. viscous lidocaine 2%, 15 mL per application, may be used as an alternative 1.

Some key considerations for treatment include:

  • Using an antiseptic oral rinse twice daily to reduce bacterial colonization of the mucosa, with options including 1.5% hydrogen peroxide mouthwash or 0.2% chlorhexidine digluconate mouthwash 1
  • Taking oral and lip swabs regularly if bacterial or candidal secondary infection is suspected, and treating candidal infection with nystatin oral suspension or miconazole oral gel 1
  • Considering the use of a topical corticosteroid four times daily, such as betamethasone sodium phosphate 0.5 mg in 10 mL water as a 3-min rinse-and-spit preparation 1

It's essential to note that most canker sores heal within 7-14 days without treatment, but these interventions can reduce discomfort and potentially speed healing. For severe or recurrent sores, prescription options like topical steroids or systemic medications may be necessary and would require consultation with a healthcare provider.

From the FDA Drug Label

Temporarily relieves pain associated with the following mouth and gum irritations: toothache sore gums canker sores braces minor dental procedures The treatment for a canker sore (aphthous ulcer) is to use a topical medication such as benzocaine to temporarily relieve pain associated with the condition 2.

  • If symptoms do not improve in 7 days, or if irritation, pain, or redness persists or worsens, users should stop use and ask a doctor or dentist 2.

From the Research

Treatment Options for Canker Sores

  • Topical oral health care medications, such as those containing benzocaine, can provide relief from pain associated with aphthous ulcers 3
  • These medications work by incorporating local anesthetics into their formulations to produce an anesthetic effect
  • Examples of such medications include Red Cross Canker Sore Medication, Maximum Strength Anbesol, and Orajel Mouth Aid, with Red Cross Canker Sore Medication showing the longest duration and greatest intensity of anesthetic effect 3

Alternative Treatments

  • A new topical oral medication, ORABASE Soothe.N.Seal, has been shown to be an effective pain-relieving adjunct to healing therapies for oral ulcerations, including canker sores 4
  • This medication can be used to alleviate pain caused by oral ulcerations, providing an alternative to topical analgesics or systemic pain medications

Most Effective Treatment

  • Amlexanox 5% paste has been found to be the most effective overall treatment for recurrent canker sores, reducing ulcer size, pain duration, and healing time 5
  • This treatment option appears to be a promising solution for individuals suffering from recurrent canker sores, providing relief from pain and promoting faster healing

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Clinical treatment evaluations of a new topical oral medication.

Compendium of continuing education in dentistry. (Jamesburg, N.J. : 1995). Supplement, 2001

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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