Fungal infections of the oral cavity

Although several strains of Candida can infect the oral mucosa, the most commonly encountered oral fungal infection is Candida albicans, which may be highly infective because of its greater level of pathogenicity and adherence properties. C. albicans is an oral commensal in as many as 40% to 65% of healthy adult mouths. The papillated dorsal surface of the tongue and palatal mucosa beneath a maxillary denture are favored reservoir sites. Oral candidal infection almost always involves a compromised host. The compromise may be local or systemic. Local factors include decreased salivation and the weaning of dentures. Systemic factors include diabetes mellitus, pernicious anemia, and AIDS. Some have even implicated advanced age and the female gender as being mild predisposing factors. Furthermore, the C. albicans infection itself can depress a host's immune system. A patient with oral candidiasis can present with one or more of the following clinical forms: pseudomembranous, erythematous, hyperplastic, and denture erythematous. Many investigators accept median rhomboid glossitis as a form of chronic oral candidiasis. In some patients with angular cheilitis, genesis of the lesions is secondary to monilial infestation. Because C. albicans is a normal inhabitant in many mouths, diagnostic confirmation of infection often rests with successful response (i.e., resolution of lesions) to antifungal medications. This form of diagnostic confirmation can be further enhanced by culturing the offending microbe, preparing a fungal smear, or even incisional biopsy. The microscopic demonstration of fungal hyphae is highly diagnostic of the candidal infection, whether the hyphae are demonstrated on a PAS smear or on a biopsy within surface stratified squamous epithelium. Numerous medications exist for the treatment of oral candidiasis. They include the antibiotic nystatin as well as clotrimazole, ketoconazole, and fluconazole. Nystatin is safe and is used as a topical agent in rinse or pastille forms. Clotrimazole is used as a topical agent in lozenge form; it is highly effective but can cause liver enzyme changes. Ketoconazole, which is usually prescribed systemically, is highly effective but also capable of causing adverse liver changes. Chlorhexidine can be used as an oral rinse or as a disinfectant for dentures.