Oral mucosal disorders are common, occurring either in isolation or in association with systemic conditions. In broad terms these disorders can be divided into four main groups : sore mouth, ulcers, blistering (vesiculobullous) disorders, and red and white patches. Many rarer conditions exist which are not discussed in this section.

Sore / Dry Mouth - Patients are usually middle aged or elderly and complain of burning pain with or without dryness. These symptoms may be linked to haematological conditions or, occasionally, conditions such as Sjögren's syndrome where investigations are normal. Reassurance is required and may be sufficient to allow the patient to cope.

Recurrent Oral Ulceration (ROU) - Is the commonest oral mucosal disorder, affecting 10-15% of people, usually when young. Most cases are of minor aphthous ulceration with small, shallow ulcers which heal in 10-14 days without scarring. Major aphthous ulcers are larger, deeper and heal in 4-6 weeks with scarring. It can be difficult to differentiate these from cancer and a specialist opinion should be sought if ulcers show no sign of healing in 2-3 weeks, by referral to an oral & maxillofacial surgeon.

Important clinical associations include other gastrointestinal pathology and unusual but important conditions such as Behcet's disease. Treatment aimed to control symptoms and steroids, usually topical, but occasional systemic are used to reduce the frequency and severity of ulceration. Analgesic and antibiotic mouthwashes reduce the pain of secondary infection.

Vesiculobullous Disorders - The main ones are pemphigoid and the potentially fatal auto-immune disease pemphigus. Differentiation is by clinical signs and the level at which the bulla lies, being subepithelial in pemphigoid and intraepithelial in pemphigus. Blood filled bullae can occur, usually on the palate, in the curious but harmless condition of angina bullosa haemorrhagica.

White and Red Patches - The important distinction is between those which are benign and those which are, or are potentially, malignant. There are therefore three main groups. First, infective lesions for example candidiasis which can occur in an acute form (oral thrush) or a chronic form usually associated with the wearing of dentures. Debilitating illness, immuno-suppression and radiotherapy are predisposing factors. Treatment is with anti-fungal therapy or occasionally laser surgery for cases of hypertrophic candidiasis.

HIV infection has numerous oral manifestations, including ulcers, infections, "hairy" leukoplakia and Kaposi's Sarcoma. Immunological conditions include oral lichen planus which is a condition which may affect skin, mucous membranes or both and is found in approximately 1% of the population. In its non-erosive form it may be asymptomatic or cause soreness. Lichenoid drug reactions are common so it is important to check the patient's medication. Steroids, usually topical, are the mainstay of treatment and good oral hygiene helps reduce symptoms. Erosive lichen planus and lichen planus affecting the tongue are considered by many clinicians to be pre-malignant and require very careful follow-up.

Dysplastic and malignant lesions can present as red and white patches. White patches in the oral cavity carry a 6% chance of malignant transformation, higher at some sites such as the floor of the mouth. Management includes the elimination of risk factors, in particular smoking especially when combined with consumption of alcohol, and biopsy and eradication often by surgical laser of patches with dysplastic change. Red patches should always be considered malignant until proven otherwise and it is essential that all these suspicious lesions are referred to the appropriate oral & maxillofacial clinic without investigation or biopsy in primary care.

In summary, many varied and important conditions affect the oral mucosa and a specialist understanding of this area and the associated medical conditions is important for the proper management of patients. Oral and maxillofacial surgeons are referred the vast majority of patients with such conditions sometimes working in collaboration with specialists in oral medicine.