Mouth ulcers
Consultation guide for UK community pharmacy: clinical features, referral criteria, time frame to resolution and management strategy.
Clinical features
- Aphthous ulcers have a clearly-defined margin, are white-yellowish-grey with a red (erythematous) periphery
- They generally occur on the inside of the lips and cheeks, the floor of the mouth or tongue
- Minor aphthous ulcers are the most common and are typically between 2 and 9 mm in diameter
- Major aphthous ulcers are larger than minor ulcers and have a raised, irregular border. They are often ≥1 cm in diameter
- Herpetiform ulcers present as multiple (5-100) pinhead-sized ulcers that may fuse together and are extremely painful. While their appearance suggests a viral cause, they are NOT actually caused by viral infection i.e. they are not caused by the Herpes virus, despite the name
Aphthous ulcer (minor)
Aphthous ulcer (major)
Referral criteria
- Suspected oral cancer (see under oral thrush heading)
- Ulceration/swelling persisting for more than 3 weeks (although some resources refer after 2 weeks since a minor aphthous ulcer should only last for 7-14 days).
- Painless ulcer/lesion
- Major aphthous or herpetiform ulcers (most OTC products are licensed for minor aphthous ulcers rather than large ulcers). Consider also referring minor ulcers that recur very frequently or when no/inadequate relief is obtained from OTC products. Typically minor aphthous ulcers occur as a single ulcer or in a small crop of up to about 5 ulcers (therefore more than this should be referred)
- Suspected underlying condition (if the ulcers first occur later in life, affect atypical sites in the mouth (such as the palate or gums), other areas of the body such as genitalia, or the presence of systemic symptoms. Could suggest various conditions including a deficiency (vitamin B12, folate, or iron), coeliac disease, ulcerative colitis or Behçet's or Reiter's syndrome or immunosuppression
- Primary or secondary oral herpes simplex infection or suspected lichen planus
- Suspected adverse drug reaction (for example NSAIDS, nicorandil, beta-blockers)
- Associated skin lesions (could suggest chickenpox or hand, foot, and mouth disease)
Time frame to resolution
- Minor aphthous ulcers and herpetiform ulcers typically heal in 10 to 14 days
- Major aphthous ulcers heal slowly over several weeks, and often lead to scarring
Management strategy
Non-pharmacological advice
- Identify and manage precipitating factors. If triggered by a particular food, avoid this. If the cause is dental in origin (for example by dentures, braces or a damaged or broken tooth) the patient should be referred to their dentist
- Avoid trauma by using a softer toothbrush, and eating softer foods
- Try relaxation techniques if linked to stress
- NB: Smoking cessation may actually precipitate ulceration, but this will resolve in a short time and the overall benefits to health are clearly greater than the risks
Pharmacological advice
- Protect ulcerated area, relieve pain, reduce inflammation, prevent/control secondary infection
- Hydrocortisone oromucosal tablets/pellets — note that these are not currently available (dm+d lists every UK pack of hydrocortisone 2.5 mg muco-adhesive buccal tablets as discontinued, most recently in September 2025), so benzydamine or chlorhexidine will usually be the practical options.
- Benyzdamine mouth rinse is useful if pain and inflammation is present and there is more than one ulcer in a hard to reach area
- Chlorhexidine helps with mouth hygiene and is good if there is more than one area, or if the area is hard to reach. Remember toothpaste incompatibilities, staining of teeth and tongue, and latest MHRA advice regarding allergies and anaphylaxis
- Choline salicylate may help with pain relief; care as excessive use/use under dentures can actually cause ulceration (not suitable under 16 years)
- Pregnancy: Corsodyl® mouthwash is okay (as per most recent PIL) but the other pharmacological measures mentioned above will typically not be licensed over-the-counter