35: Oral mucosal and salivary gland infections

Chapter 35 Oral mucosal and salivary gland infections

Oral mucosal infections

The oral mucosa, which covers a significant proportion of the oral cavity, is affected by a number of infectious diseases. The majority of these are of fungal (candidal) and viral origin and are similar to infections seen in other superficial mucosal surfaces of the body, such as the vagina. In this section, candidal infections are discussed first, followed by viral infections.

Oral candidiasis (synonym: oral candidosis)

Oral candidiasis or candidosis is mainly caused by the yeast Candida albicans, although other Candida species often cause infection. All forms of oral candidiasis are considered to be opportunistic infections, and the epithet ‘disease of the diseased’ has been applied to these infections, which are seen mainly in the ‘very young, the very old and the very sick’.

Pseudomembranous candidiasis

Pseudomembranous candidiasis, classically termed ‘thrush’ (Fig. 35.2), is an acute infection but may persist intermittently for many months or even years in patients using corticosteroids topically or by aerosol, in HIV-infected individuals, and in other immunocompromised patients. It may also be seen in neonates and in the terminally ill, particularly in association with serious underlying conditions such as leukaemia.

Hyperplastic candidiasis (Candida leukoplakia)

The lesions in hyperplastic candidiasis present as chronic, discrete raised areas that vary from small, palpable, translucent, whitish areas to large, dense, opaque plaques (Fig. 35.4), hard and rough to the touch (plaque-like lesions). Homogeneous areas or speckled areas that do not rub off (nodular lesions) can also be seen. The lesions are often asymptomatic and usually occur on the inside surface of one or both cheeks (retrocommissural area). Oral cancer supervenes in 9–40% of cases of hyperplastic candidiasis, as compared with the 2–6% risk of malignant transformation cited for oral white patches in general. Therefore, patients with recalcitrant hyperplastic candidal lesions resistant to therapy should be kept under regular surveillance.

Candida-associated lesions

Candidiasis and immunocompromised hosts

A few patients have chronic candidiasis from an early age, sometimes with a definable immune defect, e.g. chronic mucocutaneous candidiasis (Figs 35.11 and 35.12). Candidal infections in these patients are seen in the oral mucosa, skin and other body parts. These secondary oral candidal infections have increased recently because of the high prevalence of attenuated immune response, consequent to diseases such as HIV infection, haematological malignancy and treatment protocols, including aggressive cytotoxic therapy.

Oral manifestations of systemic mycoses

A number of systemic fungal infections may manifest as oral ulcerations or granulomas. Many of these are caused by dimorphic fungi and are uncommon in the West, but are seen in developing countries. These oral lesions are usually secondary diseases, the primary lesions being confined to the lungs and/or the skin. Because the primary lesion is internal, it may go unnoticed until the secondary oral lesion presents as the apparently initial manifestation of the infection (e.g. histoplasmosis). Usually, the lesions heal without causing illness, but in progressive disease, sometimes related to lung cavitation, infection can disseminate to the skin, mucosae and internal organs. In a majority of patients, the initial lesion heals, often asymptomatically, and delayed hypersensitivity develops, with a positive skin test reaction to the appropriate antigen. Almost all these infections present in the oral cavity as ulcerations.

Jan 4, 2015 | Posted by in General Dentistry | Comments Off on 35: Oral mucosal and salivary gland infections
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