The management of mouth ulcers

16 November 2018

First published November 2012

What treatments should you recommend to clients with mouth ulcers?



Mouth ulcers are a common complaint. Most people get a mouth ulcer at some point in their life and about 20% of the UK population get them repeatedly.1 This section describes the different types and their causes.


The lesions that we commonly call mouth ulcers - or more precisely aphthous ulcers - which are the subject of this module, are confined to the oral cavity and are not associated with signs of systemic illness. They are painful, clearly defined, round or oval, shallow sores, usually with a white or yellowish-grey centre, and a red inflamed rim, ranging in diameter from a few millimetres to more than a centimetre. They usually occur inside the lips and cheeks, on the floor of the mouth and on the underside of the tongue. These mouth ulcers are not associated with ulcers elsewhere on the body, and they are not the same as cold sores, which are caused by a herpes virus infection.


Mouth ulcers can be solitary or recurrent. Recurrent ulcers are also known as recurrent aphthous stomatitis (RAS) or canker sores.2 They are named according to their appearance (see Table 1):

  • Minor ulcers (Mikulicz's aphthae or mild aphthous ulcers) are small, shallow mouth ulcers and are the most common type
  • Major ulcers (Sutton's disease or periadenitis mucosa necrotica recurrens) are deeper and larger with a raised irregular border
  • Herpetiform ulcers (herpes-like) are the least common. They appear as crops of 5-100 tiny, painful blisters. These can fuse to form large, irregular ulcers, which can be extremely painful.





Some people have infrequent recurrences (2 to 4 times a year) while others have almost continuous ulcers. Each recurrence may be preceded by a tingling sensation inside the mouth for a day or two before the ulcers appear. The ulcers typically begin in childhood or adolescence, and in over 80% of cases, they develop before the age of 30 years.3 Recurrences tend to become less frequent and severe with increasing age.


Most mouth ulcers are painful. When an ulcer forms, the surface layer of the oral mucosa is removed, exposing the nerve endings. The pain is often mild, but sometimes it is so intense that it causes difficulty speaking, swallowing and eating, and may be aggravated by contact with hot, salty, spicy, acidic or abrasive foods.4 There is a potential for bacterial infection of the ulcers, which can further increase discomfort and delay healing. However, most mouth ulcers heal naturally within 14 days, and they rarely lead to any complications.


Solitary mouth ulcers are usually the result of some physical or chemical injury to the oral mucosa. Physical causes might include accidentally biting the inside of the mouth, habitual cheek or lip biting, and abrasions or rubbing caused by a rough tooth or filling, dental treatment, vigorous tooth brushing, orthodontic appliance, dentures or a sharp piece of food. Chemical injury can arise from prolonged contact of the oral mucosa with some drug treatments, or from deliberate or accidental exposure to other substances, for example after using inappropriate chemicals to clean braces or dentures.

The cause of recurrent ulcers is unknown. They don't appear to be contagious but there is probably an immunological mechanism involved and there seems to be a genetic basis. About 40% of sufferers have a first-degree relative who has mouth ulcers.1 If both parents have recurrent mouth ulcers, there is a 90% chance of developing them. But, if neither parent has them, the chances are 20%.1 In predisposed individuals, various factors may trigger recurrences, including:

  • oral trauma
  • anxiety or stress
  • food hypersensitivities ( typically to chocolate, coffee, peanuts, almonds, strawberries, cheese, tomatoes or gluten)
  • fluctuating hormone levels associated with the menstrual cycle
  • sensitivity to ingredients of oral hygiene products5
  • quitting smoking (but the ulcers quickly settle).6



Community practitioners should be able to address their clients' concerns, be able to recommend suitable treatment options, and recognise when a referral is needed. Here we provide best-practice advice to help you.


Clients with uncomplicated mouth ulcers don't necessarily need a formal assessment by a doctor. The diagnosis will often be obvious from the symptoms and clinical appearance. However, certain signs and symptoms associated with oral ulceration may indicate a more complex or systemic disorder (see Box 1) that needs fully investigating. Ulceration due to these causes will usually require specific management in addition to symptomatic treatment.


  • Infections such as hand, foot and mouth disease, and chickenpox
  • Deficiencies of iron, folate or vitamin B12
  • Coeliac disease, Crohn's, ulcerative colitis, and other malabsorption syndromes
  • Behcet's syndrome
  • Sweet's syndrome
  • Reiter's syndrome (reactive arthritis)
  • Low immunity (e.g. due to HIV, neutropenia, or chemotherapy)
  • PFAPA (periodic fever, aphthous ulcers, pharyngitis and adenitis) syndrome
  • MAGIC (mouth and genital ulcers with inflamed cartilage) syndrome
  • Oral malignancy
  • Adverse drug reaction1,8


You should advise your client to consult their GP if:

  • they have developed recurrent mouth ulcers later in life ( over 30 years of age)
  • their ulcer affects atypical sites in their mouth (e.g. the palate or gums) their ulcers are associated with signs of systemic illness (e.g. a fever)
  • they also have ulcers affecting other parts of their body (e.g. genitals)
  • any oral ulceration or mass persists longer than 3 weeks, or there are unexplained red/white patches inside the mouth, especially if these are painful, swollen or bleeding (a biopsy and other investigations may be necessary to exclude malignancy or other serious conditions).


Painful long-lasting oral ulceration could be a sign of cancer. Oral cancer is more common in men over 45 years of age who are heavy smokers and/ or drinkers.1 More than 2000 people in England and Wales die from oral cancer each year.7 Early referral may improve survival rates, so it is important to encourage those with suspicious symptoms (as above) to consult their GP promptly.


A balanced diet and active lifestyle are essential for good health, but there is no convincing evidence that any particular lifestyle changes are effective in the management of recurrent mouth ulcers. However, some people do relate recurrences to obvious trigger factors. Therefore, where relevant, you can encourage your clients to try to eliminate the cause of their mouth ulcers - for example, by:

  • using a softer toothbrush
  • using relaxation techniques, such as meditation, yoga or other exercises, to reduce stress
  • avoiding obvious trigger foods
  • switching to a different toothpaste or oral hygiene product.

If your client has recently quit smoking, you can reassure them that their mouth ulcers will quickly settle and that the health benefits of not smoking (which include a reduced risk of oral cancer) far outweigh the temporary discomfort of mouth ulcers.

If you suspect a dental cause, such as a broken tooth, ill-fitting braces or dentures (suggested by recurrent ulceration in the same part of the mouth) advise your client to see their dentist or orthodontist. Everyone, including denture-wearers, should maintain high levels of oral hygiene and have regular dental checks (at least annually). Braces-wearers should thoroughly clean their brace at least twice a day according to the advice given by their orthodontist. Denture-wearers should thoroughly clean their dentures twice a day, and leave them out at night. This helps reduce the risk of leaving food and other substances that might cause ulceration trapped beneath the dentures for long periods.


The primary goals of mouth ulcer therapy are to relieve pain, reduce inflammation and prevent infection. For those with recurrent ulcers, a secondary goal is to reduce the frequency of the ulcers. If the mouth ulcers are mild and don't interfere with your client's activities, treatment may not be needed, but for clients with painful or problematic mouth ulcers, various over-the-counter treatments are available.


For ulcers that are painful, a topical analgesic, such as choline salicylate or benzydamine hydrochloride, or an anaesthetic agent can be used. However, having found only one good-quality trial on benzydamine hydrochloride, the NHS Clinical Knowledge Summary (CKS) concludes that the evidence supporting their use is limited. 1

Choline salicylate gel

Topical gels containing choline salicylate (an analgesic and anti-inflammatory agent) are available for adults and children from 16 years of age for the relief of pain associated with mouth ulcers. Some are also licensed for the relief of pain and inflammation caused by braces, dentures and cold sores. Choline salicylate blocks cyclo-oxygenase, preventing production of prostaglandins. Massaging a small amount onto the sore area provides effective pain relief and reduces inflammation. Some gels contain an antiseptic, such as cetalkonium chloride, to help prevent infection.

Gels that contain choline salicylate and cetalkonium chloride have a long history of a favourable safety profile - one sugar­free brand with an aniseed flavour, has been available since 1966. Large-scale clinical trials have not been conducted, but in an open study of 41 patients with oral ulceration of varied aetiology, this formulation provided pain relief in 98% of cases, and more than two-thirds reported relief in less than 3 minutes.9 All patients reported relief for at least 2 hours, and almost a quarter reported relief for more than 4 hours.9 For mouth ulcers and brace sores, the client should massage a small amount of gel onto the sore area. This can be repeated after 3 hours. For ulcers and sores due to dentures, the client should massage the gel onto the sore area and leave at least 30 minutes before reinserting the dentures. The gel shouldn't be applied directly to dentures.

Benzydamine hydrochloride 0.15%

This non-steroidal anti-inflammatory drug is available in an oromucosal spray suitable for adults and children, and a mouthwash suitable from 12 years of age. Benzydamine exerts its analgesic effect by inhibiting prostaglandin synthesis. However, a small, randomized controlled trial concluded that benzydamine hydrochloride mouthwash did not significantly reduce pain compared with placebo.1 Some people find that the mouthwash causes stinging, and for them, it can be diluted with an equal volume of water before use.

Anaesthetic agents

Gels containing lidocaine hydrochloride are available for adults and children. Gels containing benzocaine are suitable from 12 years of age. These can be used to help temporarily numb the pain associated with mouth ulcers, sore gums, and denture irritation. Some gels containing lidocaine are also licensed for the relief of pain associated with children's teething. Gently rubbing a small amount on the sore area can numb it for a short time by blocking the path of pain signals along the nerves. Some formulations also contain an antiseptic to help fight infection. Care must be taken to avoid numbing the throat before eating as this can cause aspiration or choking. These gels shouldn't be used more than once every 3 hours.


Devices that form a protective barrier over the surface of the ulcer are available for adults and children over 16 years of age. The protective coat covers the exposed nerve endings to soothe pain and aid healing by physically protecting the ulcer from infection and further mechanical irritation (e.g. during eating) - sometimes for up to 4 hours. A soft precision applicator (supplied with some products) allows the mouth ulcer to be easily and hygienically targeted.


Tablets containing hydrocortisone 2.5 mg (a low-potency topical corticosteroid) may be useful for recurrent ulcers. These tablets are suitable from 12 years of age, but can be used for younger children following the advice of a doctor. However, the CKS states that evidence supporting their use is poor and inconsistent.1 Their anti-inflammatory action appears to reduce the duration and severity of mouth ulcers, but not the incidence of recurrences.1 Clients with recurrent ulcers can be encouraged to use a tablet as soon as they feel an ulcer begin to appear. They should place a tablet (up to four times a day) next to the ulcer and allow it to dissolve slowly. There is some concern that long-term use could cause adrenal suppression. However, there is little evidence of this in practice. 1 Candidiasis (thrush) is a recognised complication.


Mouthwashes or sprays containing chlorhexidine digluconate 0.2% are available for adults and children. The CKS reports that evidence to support their use in managing mouth ulcers is poor and inconsistent. 1 They may reduce the duration and severity of mouth ulcers, but not the incidence of recurrences. 1 However, they can be used (usually twice a day) to help control plaque and stop mouth ulcers becoming infected. This may be helpful if tooth brushing is too painful, and could be a useful adjunct to treatments that don't contain an antiseptic. Chlorhexidine can stain the teeth when used regularly, but the staining isn't usually permanent.


Mouth ulcers usually resolve within a couple of weeks. Your client should consult their GP if their symptoms worsen or don't improve with treatment, or if their ulcers last longer than 3 weeks. If their mouth ulcers are not adequately relieved by the above treatments, your client may be referred to an oral medicine specialist who may prescribe a stronger corticosteroid, doxycycline mouthwash or an immunosuppressant.1

Successful management

With your guidance and reassurance, your clients can learn to manage their mouth ulcers appropriately. These case studies provide ideas to help you. 

Situation 1:

Kay, a young woman with very painful, recurrent minor mouth ulcers has to make an important sales presentation at lunchtime. She asks you what she can do to make talking and eating less painful. What would you tell Kay?


Various symptomatic treatments are available to help relieve the pain of mouth ulcers. However, a device that forms a fast-acting protective barrier will help to protect the ulcer from external aggressions (food, etc.).


Explain to Kay that a product that forms a protective barrier (just like a plaster) over her ulcer may be ideal because these products help protect the ulcer from further irritation, soothe pain and aid healing. Reassure Kay that some of these devices can last for several hours - long enough to keep her comfortable during her sales presentation.

You could suggest that next time Kay's mouth ulcers begin to appear she tries using hydrocortisone 2.5 mg tablets. If Kay's mouth ulcers make tooth brushing uncomfortable, you could also suggest she uses a mouthwash containing chlorhexidine digluconate 0.2% to help control plaque.

Encourage Kay to consult her GP if her mouth ulcers are severe or frequent and not adequately relieved by over-the­counter treatments.

Situation 2:

Ricarda and her daughter Katharine (13 years old) both have fixed orthodontic braces. Katharine seems to be coping really well with her new brace but Ricarda complains of discomfort and mentions that she has developed a painful sore inside her cheek. She is anxious because she can't get an appointment with her orthodontist until the end of the week. What advice could you give Ricarda?


It takes most people a few days to get used to wearing a brace. At first, the brace can feel uncomfortable and tight against the teeth. Some parts of the brace may also rub against the inside of the mouth causing sore spots.

A gel containing choline salicylate and cetalkonium chloride can relieve pain and inflammation, and aid healing of sore spots due to braces.


Reassure Ricarda that she has done the right thing by making an appointment with her orthodontist. Explain that her mouth is probably sore because the brace is rubbing her cheek.

Tell her that the orthodontist may be able to adjust her brace or apply some dental wax to the brace to help stop this happening. In the meantime, you could suggest that Ricarda uses a chlorine salicylate gel to help relieve the pain and aid healing.

Make sure Ricarda knows that Katharine should not use the gel. Gels containing choline salicylate shouldn't be given to anyone under 16 years of age. This is because there is a possible association between salicylates and Reye's syndrome when given to children.

Situation 3:

Fred, an elderly wheelchair-bound gentleman, has a traumatic ulcer caused by his loose dentures. He asks you to fetch a tube of choline salicylate gel from his cupboard and put some on his dentures. What would you do?


Over time, dentures can become loose and ill fitting. This can lead to oral ulceration. For clients already debilitated by old age or chronic diseases, oral pain can increase vulnerability to dehydration and malnutrition.

A gel containing choline salicylate and cetalkonium chloride can relieve pain and inflammation, and aid healing of sore spots and ulcers due to dentures, but it shouldn't be applied directly to dentures.


Find out how long Fred's mouth has been sore and check that he has no worrying symptoms. Make sure Fred gets an appointment with his dentist. Explain that the dentures may need adjusting or remoulding.

Retrieve the gel and read the instructions carefully. Provided there are no contraindications, explain to Fred that he can use the gel to help relieve the pain and aid healing but that he shouldn't apply the gel directly to his dentures. Explain that he needs to massage a small amount onto the sore area in his mouth and then wait at least 30 minutes before reinserting his dentures.

Encourage Fred to maintain a high standard of oral hygiene, drink adequate fluids and eat a balanced diet. Once the problems with Fred's dentures have been resolved, he should continue to see his dentist regularly for routine checks.


Learn more about NMC revalidation here.



1. CKS (2007) Aphthous ulcer. NHS Clinical Knowledge Summaries. Available at: aphthous ulcer [ Accessed 24 June 2012].

2. SCULLY C and SHOTTS R (2000) ABC of oral health: Mouth ulcers and other causes of orofacial soreness and pain. BMf 321; 162-5.

3. SCULLY C, GORSK Y M and LOZADA-NUR F (2003) The diagnosis and management of recurrent aphthous stomatitis: A consensus approach. J Am Dent Assoc 134; 200-7.

4. FIELD EA and ALLAN RB (2003) Review article: Oral ulceration -aetiopathogenesis, clinical diagnosis and management in the gastrointestinal clinic. Aliment Pharmacol Ther 18; 949-62.

5. HERLOFSON BB and BARKVOLL P (1996) The effect of two toothpaste detergents on the frequency of recurrent aphthous mouth ulcers. Acta Odontol Scand 54(3); 150-3.

6. MARAKOGLU Ket al (2007) The recurrent aphthous stomatitis frequency in the smoking cessation people. Clin Oral Investig 11(2); 149-53.

7. NATIONAL INSTITUTE FOR HEALTH AND CLINICAL EXCELLENCE (2005) Referral for suspected cancer. Clinical guideline 27. London, RCOG Press. Available at: httn:// [Accessed 24 June 2012].

8. LEAO JC, GOMES VB and PORTER S (2007) Ulcerative lesions of the mouth: An update for the general medical practitioner. Clinics 62(6); 769-80.

9. WEG MH (1965) Report on a topical salicylate preparation for relief of pain and inflammation in dental practice. J New fer St Dent Soc 1965:

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