Skip to Main Content


The key to managing diseases of the oral mucosa is to evaluate lifestyle factors carefully, including causes of immune suppression.


Evaluating the sore mouth and tongue is basically an understanding of disorders of the oral mucosa. Disorders of the oral mucosa are a common problem in general practice, with recurrent aphthous ulceration being the most common oral mucosal disease in humans.

There are three types of stratified squamous epithelium in the oral mucosa:1

  1. masticatory—surface layer, cornified (orthokeratinised), attached to underlying periosteum (e.g. hard palate and gingivae)

  2. lining—(e.g. lip and buccal mucosa, alveolar mucosa, floor of mouth, soft palate and tongue—lateral and undersurface)

  3. specialised—with taste buds and papillae, e.g. on dorsum of tongue

Red flag pointers for oral conditions

  • Dehydration in children with herpetic gingivostomatitis

  • Petechiae on soft palate with gingivostomatitis or pharyngotonsillitis

  • Oral ulcers and skin disorders

  • Oral ulcers (especially solitary) or soft tissue lesions persisting for >3 weeks

  • Oral ulcers and bowel dysfunction

  • Oral candidiasis (may indicate diabetes or other immunosuppression)

  • Glossodynia may indicate psychological disorder (e.g. depression)


The histology of oral ulceration is usually non-specific, with fibrin slough covering granulation tissue, and the aetiology is varied. The ulceration is a breach in the epithelial compartment with inflammatory cell infiltrate in the submucosa. The most common form is recurrent aphthous ulceration. Always inquire about a history of skin problems, medication, bowel function and psychological stress.

Key facts and checkpoints

  • Dental trauma or neglect is an important cause of many oral mucosal disorders, such as ulceration, bleeding gums and hyperplasia.

  • Non-healing oral ulcers warrant biopsy to exclude squamous cell carcinoma (SCC).

  • If oral mucosal cancer is suspected, palpate the lesions to check for induration or a firm, discrete edge and check regional nodes.

  • Any oral ulcer or soft tissue lesion that persists 3 weeks after the apparent cause has been removed should be biopsied. The initial ‘cause’ (e.g. tooth biting lip) may be just the trigger for noticing the lesion.

  • Consider Epstein–Barr virus (EBV) infection with unusual faucial ulceration and petechial haemorrhages of the soft palate.

  • Aphthous ulcers are usually 3–5 mm in diameter—minor ones have an erythematous margin.

  • Intraoral bony exostoses, other than palatal and mandibular tori, are often variations of normal, or less commonly part of a syndrome, e.g. Gardner syndrome. No treatment is usually required.2

  • Shared care of more complex lesions of the mouth and tongue with an oral or dental surgeon is best practice.

A list of causes is presented in the diagnostic strategy model (see TABLE 61.1). Depending on the clinical picture, investigations may include FBE, swabs, autoantibody screen, syphilis serology, blood sugar, vitamin B12 and folate levels, and biopsy.

Table 61.1Mouth ulcers: diagnostic strategy model

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.