Aphthous mouth ulcers are painful, clearly defined, round or ovoid, shallow ulcers that are confined to the mouth and are not associated with systemic disease. They are often recurrent, with onset usually in childhood.


  • Incidence: 5000.00 cases per 100,000 person-years
  • Peak incidence: 20-30 years
  • Sex ratio: more common in females 1:1
<1 1-5 6+ 16+ 30+ 40+ 50+ 60+ 70+ 80+


Single ulcers, or recurrent ulcers in the same place, may be caused by damage to the mouth, for example biting the cheek, or damage to the buccal mucosa with a toothbrush or a sharp tooth or filling.

People with recurrent ulcers may have a genetic predisposition. Precipitating factors include:
  • Oral trauma (for example excessive tooth brushing).
  • Anxiety or stress.
  • Certain foods (typically chocolate, coffee, peanuts, almonds, strawberries, cheese, tomatoes, and wheat flour).
  • Stopping smoking.
  • Hormonal changes related to the menstrual cycle.

Clinical features

Aphthous ulcers present as one or more rounded or ovoid mouth ulcers with a clearly-defined margin, a floor of yellowish-grey slough, and an erythematous periphery. They generally occur on non-keratinized mucosal surfaces such as the inside of the lips, the inside of the cheeks, the floor of the mouth, or the undersurface of the tongue.


Investigations are generally unnecessary. Investigations should be considered (for example full blood count, erythrocyte sedimentation rate, ferritin, folate and vitamin B12) if an underlying systemic disease is suspected based on history and examination findings.


Most aphthous ulcers heal within 10-14 days without scarring.

Management of aphthous ulcers includes:
  • Avoidance of precipitating factors, and
  • Symptomatic treatment for pain, discomfort, and swelling e.g. a short course of a low potency topical corticosteroid (hydrocortisone lozenges), an antimicrobial mouthwash, or a topical analgesic.
  • People with a mouth ulcer that persists for more than 3 weeks should be referred urgently to a specialist