“Candidiasis” refers to a multiplicity of diseases caused by a yeastlike fungus, Candida, and is the most common oral fungal infection in humans. The various diseases are classified in Table 5-1 according to onset and duration (acute or chronic); clinical features, including color (erythematous/atrophic); location (median rhomboid glossitis, denture stomatitis,
multifocal candidiasis, and angular cheilitis); the presence of skin lesions as well as oral lesions (mucocutaneous); and association with an immunocompromised host (HIV associated). Other clinical features include a hyperplastic or hypertrophic appearance (papillary hyperplasia of the palate, candidal leukoplakia, and hyperplastic median rhomboid glossitis). Candida is predominantly an opportunistic infectious agent that is poorly equipped to invade and destroy tissue. The role of Candida as opportunistic invader versus etiologic agent in patients with oral white lesions has not been clearly established. However, the demonstration of the catalytic role of some Candida strains in endogenous cellular nitrosamine production,the statistically significant association of certain strains with dysplastic red and white lesions (speckled leukoplakia),and the hyperplastic effects on epithelium of Candida in vitro,indicate that Candida may be a carcinogen or promoting agent, rather than only an innocuous opportunistic infectious entity.