Causes of mouth ulcers^[1]

For more detail see separate article Oral Ulceration.

• Idiopathic:
  • Aphthous ulcers or recurrent aphthous stomatitis (common in the general population)
• Infective:
  • Herpetic gingivostomatitis
  • Varicella-Zoster virus (as chickenpox or shingles)
  • Hand foot and mouth disease
  • Oral candidiasis
  • Other infections: acute necrotising gingivitis, herpangina, infectious mononucleosis, tuberculosis, syphilis, HIV.
• Oral cancer (most are squamous cell carcinomas)
  • May present as persistent ulcer (see box above).
• Dermatological:
  • Lichen planus (LP)
  • Pemphigus and pemphigoid
  • Erythema multiforme and Stevens-Johnson syndrome
  • Dermatitis herpetiformis
  • Some other ulcerative/bullous conditions, eg chronic ulcerative stomatitis, epidermolysis bullosa
• Haematological:
  • Anaemia
  • Leukaemia
  • Neutropenia or other white cell dyscrasias
• Gastroenterological:
  • Coeliac disease
  • Crohn's disease
  • Ulcerative colitis
• Rheumatological:
  • Systemic lupus erythematosus (SLE)
  • Behçet's syndrome
  • Sweet's syndrome (febrile neutrophilic dermatosis)
  • Reiter's disease
• Pharmacological/iatrogenic:
  • Cytotoxics and radiotherapy
  • Nicorandil
  • Antithyroid drugs
  • Many others

Aphthous ulcers

• These are also referred to as canker sores, aphthous stomatitis, recurrent aphthous stomatitis (RAS), recurrent oral ulceration (ROU).
• This condition tends to start in childhood or adolescence. There are recurrent small, round or ovoid ulcers with circumscribed margins, erythematous haloes and yellow or grey floors.
• They affect at least 20% of the population and their natural course is one of eventual remission.^[1]

Herpetic disease

• Gingivostomatitis - primary infection of herpes simplex virus type 1 (HSV-1) tends to occur in children under five years old. Infection occurs through intimate contact (eg saliva) and viral shedding goes on from 4 to 60 hours following onset of symptoms (incubation period is 2-12 days). It may well be asymptomatic but patients who do present tend to do so with gingivostomatitis in children and as pharyngotonsillitis or a mononucleosis (glandular fever) type of illness in adults.There may be prodromal symptoms including fever, nausea, malaise, headache and irritability. This self-limiting condition can be adequately managed symptomatically with:
  • Analgesia (eg paracetamol)
  • Good fluid intake
  • Avoidance of salty or acidic foods
  • Topical benzydamine may be helpful for pain relief
  • Chlorhexidine mouthwash should minimise secondary infection
  • Lip barrier preparations (eg Vaseline®) can be helpful
  Steps should be taken to minimise transmission:
  • Avoid touching the lesions - if this is necessary, such as after applying lip cream, wash hands afterwards
  • Avoid kissing and oral sex until the lesions have healed
  • Avoid sharing items which come into contact with the lesions
  • If children are well, they do not need to be excluded from school or nursery
  Referral is appropriate for immunocompromised or pregnant patients, if there is a risk of dehydration or if ulcers do not heal within 14 days.
  
  
• Cold sores - this is the reactivation of latent HSV-1 which has remained dormant in the trigeminal ganglion. Cold sores are common and result in recurring symptoms in 20-40% of young adults who are seropositive for HSV-1.
  • This is usually a self-limiting condition (7-10 days) which can be managed symptomatically as with gingivostomatitis (above) with the same precautions needed to minimise the risk of transmission.
  • Topical antiviral treatment is widely available and may affect the course of the current episode if applied in the prodromal phase but they do not cure the patient or prevent further episodes. Prophylactic use is ineffective.
  • Refer pregnant women (particularly towards the end of the pregnancy) and immunocompromised patients, for specialist advice on management.

Oral candidiasis

This is a fungal infection of the oral mucosa, usually caused by Candida albicans, or sometimes by other Candida spp. Factors predisposing to oral candidiasis:

• Diabetes; other endocrine disorders, eg hypothyroidism, Addison's disease.
• Severe anaemia, malnutrition, deficiency of iron, folate, or vitamin B12.
• Immunocompromise or immunosuppression.
• Poor dental hygiene, local trauma, mucosal irritation, smoking.
• Drugs - broad spectrum antibiotics and inhaled/oral corticosteroids.

Symptoms:

• Pain - may make eating and drinking difficult
• Altered sense of taste - sometimes
• May be asymptomatic

Signs - there are several clinical forms of oral candidiasis (see separate article Candidiasis).

Other causes of sore mouth

Burning mouth syndrome^[2][3]

This idiopathic condition is characterised by a burning sensation in the tongue or other parts of the mouth in the absence of medical or dental causes.

• Exclude local and systemic factors (such as xerostomia, infections, allergies, ill-fitting dentures, hypersensitivity reactions and hormone and vitamin deficiencies) before diagnosing burning mouth syndrome.
• Dryness and taste disturbance are also often present.
• Symptoms are sometimes relieved by eating and drinking (unlike mouth ulcers, which are more painful on eating).
• It is more common in older adults (past middle age).
• The cause is unclear - it may be a form of neuropathy.

Geographic tongue (benign migratory glossitis)^[4][5]

This is a common idiopathic condition affecting up to 10% of children and adults.

• It presents with map-like red areas (hence its name) of atrophy of filiform tongue papillae. The areas and patterns may change rapidly (over hours). The tongue is often fissured.
• Lesions may be asymptomatic but can cause soreness.
• The cause is unknown.
• Diagnosis is based on the appearance. No treatment is necessary unless the diagnosis is unclear.
• There is no known effective therapy but zinc supplementation has been used with some anecdotal evidence of benefit. Avoidance of spicy foods may help symptomatically.

Desquamative gingivitis^[6]

• This is widespread erythema and soreness of the gingiva, worse on eating.
• It is usually found in women over middle age, as a manifestation of LP or mucous membrane pemphigoid.
• Diagnosis is usually obvious from the history and clinical features, but biopsy and immunostaining may be needed to establish the precise cause.
• Management involves treating the underlying cause, improved oral hygiene and topical corticosteroids.

Children's mouth problems

Causes or sore mouth or mouth ulcers to consider in children are:

• Dental disease
• Kawasaki disease where the child has fever and irritability, particularly if there is a rash, erythema/desquamation of the extremities, conjunctivitis or cervical lymphadenopathy.
• Hand foot and mouth disease is another important acute cause of sore mouth in children.
• Herpetic gingivostomatitis or oral candidiasis - as above.
• Cancrum oris - this is a serious condition characterised by a rapid, painless and extensive necrosis of oral cavity that can involve cheek, nose, palate and bones. It almost always occurs in the context of poor oral hygiene and in developing countries. It may be preceded by excessive salivation, malodour from the mouth, grey discoloration and gingival ulcer formation. See separate article Cancrum Oris (Noma).

Swellings in the mouth^[4]

Note: persistent swellings in the mouth should be referred for an oral surgery opinion to avoid missing oral cancers.

Swellings related to salivary glands:

• Mucocele - a swelling of the inner surface of the mouth or ventral surface of the tongue. It is due to obstruction or rupture of a small salivary gland duct. It may have a bluish, translucent colour. When it occurs on the floor of the mouth it is known as a ranula.
• Swellings of the sublingual salivary glands may be felt in the floor of the mouth. See separate article Salivary Gland Disorders.

Other swellings in the mouth may be due to a wide range of conditions.^[4] The list below outlines some of the more common causes:

• Non-pathological – unerupted teeth, pterygoid hamulus, parotid papillae, lingual papillae
• Developmental – haemangioma, lymphangioma, maxillary and mandibular tori (bony exostoses), hereditary gingival fibromatosis, Von Recklinghausen's neurofibromatosis
• Inflammatory – abscess, granulomatosis, sarcoidosis, pyogenic granuloma, Wegener's granulomatosis
• Traumatic – epulis, fibro-epithelial polyp, denture granulomas
• Cystic – eruption cysts, developmental cysts, infective cysts, ranula (mucocele of the minor salivary glands)
• Fibro-osseous – fibrous dysplasia, Paget's disease of bone
• Hormonal – pregnancy epulis, pregnancy gingivitis, oral contraceptive pill gingivitis
• Drugs – phenytoin, calcitonin, calcium channel blockers
• Tumours – benign and malignant
• Haematological – leukaemias, lymphomas
• Miscellaneous – angio-oedema, amyloidosis

Red lesions of the oral mucosa^[4]

Red lesions of the oral mucosa are usually inflammatory in nature but may also be malignant, especially erythroplasia. The table below lists some important causes of red lesions of the oral mucosa.

White lesions of the oral mucosa^[8]

Leukoplakia

• This term was formerly used to describe all white lesions of the oral mucosa, but should now be reserved for those of unknown cause or those that are considered to be premalignant.
• A small but significant proportion of such lesions will progress to become malignant. Referral for biopsy is required.^[10] However, most white lesions in the mouth are relatively benign keratoses caused by friction from teeth, cheek biting or tobacco smoking.
• A variety of treatments have been used to try and encourage resolution of leukoplakic lesions and prevent malignant transformation, but their efficacy is unproven.^[10]
• Significantly dysplastic lesions are usually treated by excision by conventional means or laser. There is a significant recurrence rate.^[11]

Hairy leukoplakia^[12]

• This is an white, asymptomatic lesion, usually on the lateral margin of the tongue.
• It is associated with the Epstein-Barr virus and with immunocompromise.
• The lesions vary in appearance from smooth, flat, small lesions to irregular "hairy" or "feathery" lesions with prominent folds or projections, located on the margins, dorsal or ventral surfaces of the tongue or on buccal mucosa.
• Treatment options include systemic antiviral therapy (eg acyclovir 800 mg five times a day), topical therapy with podophyllin or retinoic acid, or cryotherapy.

For more details on both of these conditions see separate related article Leukoplakia.

Oral LP^[4]

This inflammatory condition commonly presents in older patients, with white patches affecting the mucosa of the mouth or tongue bilaterally.

• Refer for biopsy and follow-up to exclude or monitor for malignancy.
• There is a small risk of developing malignancy, so follow-up is required, although as yet it is not clear if surveillance of such cases is definitely associated with better outcomes.^[13]
• Treatment with a topical corticosteroid can help control symptoms. There is no clear evidence for other treatments.^[14]

See related separate article on Lichen Planus.

Pigmented oral lesions

• Blue/purple patches may be haemangiomas (will blanch with pressure), Kaposi's sarcoma (will not blanch) or purpura/ecchymoses (non-blanching, usually smaller lesions). Other rarer causes include heavy-metal toxicity or Peutz-Jeghers' syndrome.
• Brown or black lesions may be caused by staining from fillings (so-called amalgam tattoo) or naevi (freckles) but could rarely be due to melanoma, so referral for biopsy should be considered.
• If the tongue is furred and brown/black and/or appears hairy (particularly on its posterior portion), this is likely to be due to poor oral hygiene. It can be a problem in edentulous patients, those with a soft diet, those who smoke, those who are fasting or ill or are using antimicrobials or chlorhexidine long-term. At its extreme this condition is termed black, hairy tongue. The condition is treated by improving oral hygiene, brushing the tongue or using a tongue scraper, increasing dietary fruit and roughage (pineapple is useful) and the use of sodium bicarbonate mouthwash.^[4]
• Generalised pigmentation of the oral mucosa can be a normal feature in people of dark-skinned races. Certain medications (eg phenothiazines, zidovudine, minocycline) and smoking can rarely cause it, as can Addison's disease or ectopic production of ACTH, eg by carcinoma of bronchus.

Dry mouth^[15]

Also known as xerostomia, this is characterised by a dry mouth sensation ± difficulty in speaking or swallowing due to thick or sticky saliva. Individuals may also complain of halitosis. A wide range of conditions may cause this problem. Relatively common causes are listed below:

• Psychogenic causes including burning mouth syndrome (see above)
• Age-related
• Anticholinergic medication (particularly tricyclic antidepressants)
• Various other medication, including diuretics
• Sjögren's syndrome
• Head and neck radiotherapy
• Any cause of salivary gland dysfunction (see separate article, Salivary Gland Disorders)

Treatment is with hydrating agents to provide moisture and comfort - usually gels or sprays. Good dental care is important because dry mouth predisposes individuals to tooth decay.

For more information see related separate article Dry Mouth (Xerostomia) and its Treatment.

Halitosis

• Common causes are poor oral hygiene and gingivitis/periodontal disease.
• Other possible causes are acute or occult illness, including chest infection, bronchiectasis, lung abscess, appendicitis, gastroenteritis, undiagnosed diabetes or foetor hepaticus from liver disease.
• Possible treatments, depending on the cause, are smoking cessation, better oral hygiene, use of antiseptic mouthwashes and regular dental follow-up.

See separate article Halitosis for further information.

Tooth and gum disorders

These are best dealt with by a dental general practitioner. However, current NHS dentistry provision is increasingly patchy, so such problems are presenting to medical primary care and emergency departments more frequently. See separate article Some Dental and Periodontal Diseases for more detail.