What is a mouth ulcer?
A mouth ulcer is damaged oral epithelium and its underlying lamina propria. Mouth ulcers are a common form of stomatitis and may be due to trauma, irritation, radiation, infections, drugs, inflammatory disorders, and unknown causes.
The most common presentation of mouth ulcers is with painful, recurrent aphthous stomatitis, also known as aphthosis, aphthae, aphthous ulcerations, and canker sores.
Who gets mouth ulcer and how are mouth ulcers classified?
Males and females of all ages and races experience mouth ulcers.
Acute and recurrent infection
- Candida albicans infection: oral thrush in babies, elderly and debilitated
- Herpes simplex: primary (in children) or recurrent cold sores (any age)
- Enterovirus 71 infection: hand, foot and mouth disease (children or adults of any age)
- Herpangina (children)
- Epstein–Barr virus and cytomegalovirus (adolescents)
- Varicella-zoster virus: chickenpox (children) or sometimes, shingles (any age, especially elderly)
- Various consequences of human immunodeficiency virus infection
- Secondary syphilis: snail track ulcers
Acute single-episode ulceration
- Stevens-Johnson / toxic epidermal necrolysis (any age)
- Acute necrotising ulcerative gingivitis
- Drug-induced stomatitis — eg, chemotherapy, low-dose methotrexate (irritant), non-steroidal anti-inflammatory drugs (NSAIDs) (lichenoid pattern)
- Acute febrile neutrophilic dermatosis (Sweet syndrome) — with papulovesicular plaques, fever, neutrophilia
- Aphthous ulceration: up to 20% children > older age; more common in Caucasians than other races, more common in females than in males
- Complex aphthosis: almost constant ulcers, oral and genital aphthous ulcers (adolescents, adults)
- Behcet disease: oral and genital aphthous ulcers, ocular inflammation, skin lesions, pathergy and other symptoms and signs due to multisystem vasculitis (adults)
- Contact stomatitis: in adults eg, nicotine (irritant) or rubber (allergy)
- Erythema multiforme major: associated with herpes simplex virus activation in adolescents and young adults
- Oral lichen planus: may have cutaneous and mucosal lichen planus at other sites in middle-aged adults
- Systemic lupus erythematosus: especially young females
- Chronic ulcerative stomatitis: affects middle-aged women
- Orofacial granulomatosis: affects young adults; may have swollen lips and other orofacial features
- Blistering skin conditions: especially pemphigus, linear IgA bullous dermatosis, mucous membrane pemphigoid — vesicles that erode/ulcerate; may have cutaneous lesions (adults)
Chronic mouth ulcer
- Trauma eg, due to dentures (adults) or chemical injury from aspirin or cocaine
- Infection: tertiary syphilitic gumma, tuberculosis, aspergillus, histoplasmosis, leishmaniasis
- Eosinophilic ulcer (children or adults)
- Membranous mucositis due to radiation therapy
- Necrotising sialometaplasia: an ischaemic event
- Squamous cell carcinoma: invasive cancer and/or in situ leukoplakia (mostly affects smokers)
- Non-Hodgkin lymphoma
Differential diagnosis includes other inflammatory disorders in which there is no true ulceration, such as migratory glossitis/geographic tongue.
Traumatic mouth ulcers due to ill-fitting dentures
What causes aphthous mouth ulcer?
The cause or causes of aphthous mouth ulcers are not well understood. Current thinking is that the immune system is disturbed by some external factor and reacts abnormally against a protein in mucosal tissue.
Although most people with aphthous stomatitis are healthy, it may relate to:
- Genetic factors; a strong family history of aphthous stomatitis is common
- Other illness, lack of sleep, being “run down”, psychogenic stress
- Trauma from an inadvertent bite or brushing teeth
In some patients, there are additional predisposing factors:
- Hormones: ulcers may recur according to the menstrual cycle
- Micronutritional deficiencies of iron, B12, or folate
- Gluten-sensitive enteropathy (coeliac disease)
- Food additive or food allergy
- Nicorandil (a drug given for angina)
- Inflammatory bowel disease
- Reactive arthropathy
- Cyclic neutropenia.
What are the clinical features of a mouth ulcer?
Patients may present to doctors or dentists with a mouth ulcer for assessment and treatment. They can also have cutaneous and systemic symptoms and signs.
A patient with a mouth ulcer should be questioned and examined with a differential diagnosis in mind.
- Is the ulcer solitary or are there multiple ulcers?
- What part or parts of the mouth are involved?
- Is the patient feeling well or unwell?
- Is this a single episode, or have the ulcers occurred before?
- Does the patient have any underlying condition or disease?
- Does anyone else close to the patient have similar symptoms?
Recurrent aphthous ulceration
- One or many lesions scattered throughout the mouth
- Round or ovoid in shape
- Surrounded by an erythematous halo
- Punched-out yellow-grey centre
- Painful, especially on eating or drinking.
Recurrent aphthous ulcers are divided into 3 types.
- Minor recurrent aphthous ulceration: lesions are under 10 mm in diameter and heal within 10–14 days.
- Major recurrent aphthous ulceration (much less common); coalescent or large ulcers with raised margins > 10 mm in diameter that take longer to heal; often associated with fever, dysphagia, malaise.
- Herpetiform recurrent aphthous ulceration: this is is uncommon, and is characterised by crops of numerous grouped 1–3 mm ulcers on or under the tongue.
What are the complications of a mouth ulcer?
Most mouth ulcers heal without a problem.
- Major aphthous ulcer and Behcet ulceration may heal with scarring.
- Acute ulceration can lead to secondary bacterial infection.
- Chronic ulceration due to oral lichen planus predisposes to oral squamous cell carcinoma (in ~5%).
How are mouth ulcers diagnosed?
Mouth ulcers are usually easy to diagnose. Consider biopsy of a non-healing ulcer, particularly if considering cancer. It should be taken from the indurated edge of an inflammatory ulcer or from an inflamed but non-ulcerated site.
- Aphthous ulceration has varying and nonspecific features
- Oral lichen planus and erythema multiforme may show a lichenoid tissue reaction
If the patient has frequent, prolonged or large ulcers, or is unwell, the following tests may be done to assess general and gastrointestinal health.
- Bacterial and viral swabs from the ulcers
- Complete blood cell count
- Iron, B12 and folate
- Coeliac antibodies
- Faecal calprotectin (a test for inflammatory bowel disease)
Selected patients may undergo further assessment including endoscopy if there is suspicion of inflammatory bowel disease.
If a specific toothpaste or food is thought to precipitate ulcers, allergy tests including prick tests, patch tests and specific IgE testing may be performed. The results can be difficult to interpret.
What is the treatment for mouth ulcer?
Symptomatic relief may be obtained from:
- Avoidance of hard, spicy, salty, or acid food
- Avoidance of toothpaste containing sodium lauryl/laureth sulphate
- Antiseptic, anti-inflammatory and analgesic mouthwash or spray
- Pain relief and local treatment
- Choline salicylate gel applied to ulcers (adults only)
- Nd:YAG laser or silver nitrate cautery
- Topical corticosteroid paste, solution, spray or ointment
- Topical calcineurin inhibitors: topical pimecrolimus or tacrolimus.
- Sucralfate solution
- Tetracycline mouthwash
Nicotine-containing gum has been reported to be effective, but it is not recommended because it’s highly addictive and has many adverse effects (see smoking).
Systemic therapy is intended to reduce the frequency of ulceration. A Cochrane review (2012) of systemic treatments for recurrent aphthous stomatitis was inconclusive. The following are reported to be useful in at least some patients.
- Systemic corticosteroids
- Immunomodulatory agents such as azathioprine, methotrexate, ciclosporin
- Tumour necrosis factor (TNF) antagonists (adalimumab, etanercept, infliximab)
- Thalidomide (in exceptional cases)
Mouth ulcers are not preventable in all patients. Some people can reduce the number and severity of their ulcers by ensuring plenty of rest and avoiding known triggers.
What is the outlook for mouth ulcers?
There is a gradual tendency for recurrent aphthous stomatitis to become less severe in later life.