How Do I Manage a Patient with Aphthous Ulcers?


Aphthous Ulcers (also known as aphthous stomatitis, canker sores)

Single or multiple ulcerations of the oral mucosa; usually self-limiting, painful, or recurrent.



  • Typical onset in childhood or early adulthood
  • Women affected more often than men


Minor aphthous ulcerations (Fig. 1)

  • Approx. % of cases: 80%
  • Shape and dimensions: round to ovoid ulcers no larger than 2–8 mm in diameter surrounded by a thin erythematous halo
  • Site of occurrence: non-keratinized oral mucosa (usually)
  • Healing time: 10–14 days
  • Scarring potential: no

Major aphthous ulcerations (Fig. 2)

  • Approx. % of cases: 10–15%
  • Shape and dimensions: round to ovoid ulcers larger than 10 mm in diameter
  • Site of occurrence: keratinized and non-keratinized oral mucosa
  • Healing time: 2–8 weeks
  • Scarring potential: yes

Herpetiform aphthous ulcerations (Fig. 3)

  • Approx. % of cases: 5–10%
  • Shape and dimensions: multiple, recurrent crops of small (2–3 mm), painful ulcers (100+); often coalesce into larger irregular ulcers
  • Site of occurrence: keratinized and non-keratinized oral mucosa
  • Healing time: 10–14 days
  • Scarring potential: no

Figure 1: Minor aphthous ulcer

Figure 2: Major aphthous ulcers

Figure 3: Herpetiform aphthous ulceration



Pain severity depends on the variant, but is often out of proportion in relation to the size of the lesions.

Onset Factors

  • Attacks may be precipitated by a variety of events including local trauma, stress, food additives/preservatives (e.g., cinnamaldehyde, sodium benzoate), medications, hormonal changes, vitamin deficiencies (B12, folic acid), iron deficiency, cessation of smoking, and possible sensitivity to sodium lauryl sulfate.
  • Genetic, immunological, and microbial factors have also been implicated in the onset of recurrent aphthous ulcerations.
  • Recurrent aphthous ulcerations may be a marker for an underlying systemic illness such as celiac disease/inflammatory bowel disease, vasculitis (e.g., Behcet syndrome), reactive arthritis (e.g., Reiter syndrome), and HIV/AIDS.


  • Perform a complete extraoral (head and neck) and intraoral examination.
  • Review past dental history to rule out any local pathology as a source of pain. Common pathologies might include a traumatic ulceration: arising from a fractured restoration, tooth, or denture.

Rule Out Systemic Pathologies

Thoroughly review the patient’s medical history for possible:

  • Gastrointestinal disorders (e.g., celiac disease/inflammatory bowel disease)
  • Hematologic disorders (e.g., iron deficiency)
  • Nutritional deficiencies(e.g., vitamin deficiencies)
  • Immunologic disorders (e.g., HIV/AIDS, Behcet syndrome)


Based on the clinical examination and on the patient’s medical history, a diagnosis of aphthous ulcers is determined.


Common Initial Treatments

Treatment strategies are directed to providing symptomatic relief through:

  • Pain reduction
  • Prevention of recurrent episodes
  • Accelerate healing of ulcers

Mild Disease (Minor Aphthous Ulcers)

Topical analgesics/anti-inflammatory agents

  • Topical analgesic pastes [e.g., 20% benzocaine] (to reduce ulcer pain): apply as needed
  • Benzydamine hydrochloride mouthrinse [e.g., Tantum®] (to reduce ulcer pain): apply q.i.d. for 2 weeks or until ulcers heal
  • 5% lidocaine gel/viscous xylocaine (to reduce ulcer pain): rinse and spit as needed
  • Protective bioadhesives [e.g., Orabase®] (to reduce ulcer pain): apply as needed


  • 0.12% chlorhexidine mouthrinse (to reduce ulcer pain and duration of lesions): rinse b.i.d. for 2 weeks or until ulcers heal

Topical corticosteroid agents

  • 0.1% triamcinolone [e.g., Kenalog in Orabase®, Oracort®] (to reduce pain and inflammation): apply t.i.d. or q.i.d. for 5 days

Acute Management of Severe Disease

Corticosteroids (high-potency topical agents usually in combination with antifungal prophylaxis and/or systemic medication). Consider referral to health care provider with advanced knowledge/expertise in managing patients taking these types of medications.

Physical Therapy

  • Surgical removal
  • Laser ablation
  • Chemical cautery


  • Thalidomide
  • Pentoxifylline
  • Colchicine


  • Patients who suffer from frequent, recurrent episodes of aphthous ulcers should be referred to either an oral medicine/oral pathology specialist or their physician to rule out any possible systemic association with recurrent aphthous stomatitis.
  • Laboratory investigations may include complete blood count with differential, serum iron/folate/vitamin B12 levels, and additional tests (as deemed appropriate) to rule out other possible underlying systemic disorders.
  • Screening for celiac disease may also need to be ruled out.
  • Persistence of any ulcer (painful or not) for more than 2 weeks requires further evaluation to rule out:
    • Cancer
    • Other infections (e.g., Herpes simplex virus, fungal infection)
    • Chronic mucocutaneous diseases (e.g., lichen planus, pemphigus, pemphigoid)



Dr. Clark is clinical director of dental services at Ontario Shores Centre for Mental Health Sciences and associate in clinical dentistry with the department of oral medicine, faculty of dentistry, University of Toronto.

Correspondence to: Dr. David Clark, Ontario Shores Centre for Mental Health, 700 Gordon Street, Whitby ON  L1N 5S9. Email:

The author has no declared financial interests.

This article has been peer reviewed.

Suggested Resources

  1. Preeti L, Magesh KT, Rajkumar K, Karthik R. Recurrent apthous stomatitis. J Oral Maxillofac Pathol. 2011;15(3):252-6.
  2. Rashid M, Zarkadas M, Anca A, Limeback H. Oral manifestations of celiac disease: a clinical guide for dentists. J Can Dent Assoc. 2011;77:b39.
  3. Scully C. Clinical practice. Apthous ulceration. N Eng J Med. 2006;355(2):165-72.