Oral candidiasis

Oral candidiasis is a mycosis (fungal infection). Traditionally, oral candidiasis is classified using the Lehner system, originally described in the 1960s, into acute and chronic forms (see table). Some of the subtypes almost always occur as acute (e.g., acute pseudomembranous candidiasis), and others chronic. However, these typical presentations do not always hold true, which created problems with this system. A more recently proposed classification of oral candidiasis distinguishes primary oral candidiasis, where the condition is confined to the mouth and perioral tissues, and secondary oral candidiasis, where there is involvement of other parts of the body in addition to the mouth. The global human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) pandemic has been an important factor in the move away from the traditional classification since it has led to the formation of a new group of patients who present with atypical forms of oral candidiasis. Where it is associated with inhalation steroids (often used for treatment of asthma), erythematous candidiasis commonly appears on the palate or the dorsum of the tongue. Indeed, it can be clinically indistinguishable from true leukoplakia, but tissue biopsy shows candidal hyphae invading the epithelium. Some sources use this term to describe leukoplakia lesions that become colonized secondarily by Candida species, thereby distinguishing it from hyperplastic candidiasis. It is known that Candida resides more readily in mucosa that is altered, such as may occur with dysplasia and hyperkeratosis in an area of leukoplakia. Associated lesions Candida-associated lesions are primary oral candidiases (confined to the mouth), where the causes are thought to be multiple. Candida organisms alone are responsible for about 20% of cases, or "Candida-associated denture-induced stomatitis" (CADIS), Although this condition is also known as "denture sore mouth", Others Chronic multifocal oral candidiasis This is an uncommon form of chronic (more than one month in duration) candidal infection involving multiple areas in the mouth, without signs of candidiasis on other mucosal or cutaneous sites. The lesions are variably red and/or white. Unusually for candidal infections, there is an absence of predisposing factors such as immunosuppression, and it occurs in apparently healthy individuals, normally elderly males. Smoking is a known risk factor. Chronic mucocutaneous candidiasis This refers to a group of rare syndromes characterized by chronic candidal lesions on the skin, in the mouth and on other mucous membranes (i.e., a secondary oral candidiasis). These include Localized chronic mucocutaneous candidiasis, diffuse mucocutaneous candidiasis (Candida granuloma), candidiasis–endocrinopathy syndrome and candidiasis thymoma syndrome. About 90% of people with chronic mucocutaneous candidiasis have candidiasis in the mouth. ==Signs and symptoms==

Signs and symptoms are dependent upon the type of oral candidiasis. Often, apart from the appearance of the lesions, there are usually no other signs or symptoms. Most types of oral candidiasis are painless, but a burning sensation may occur in some cases. Candidiasis can, therefore, sometimes be misdiagnosed as burning mouth syndrome. A burning sensation is more likely with erythematous (atrophic) candidiasis, whilst hyperplastic candidiasis is normally entirely asymptomatic. Acute atrophic candidiasis may feel like the mouth has been scalded with a hot liquid. Another potential symptom is a metallic, acidic, salty or bitter taste in the mouth. The pseudomembranous type rarely causes any symptoms apart from possibly some discomfort or bad taste due to the presence of the membranes. Sometimes the patient describes the raised pseudomembranes as "blisters." Occasionally there can be dysphagia (difficulty swallowing), which indicates that the candidiasis involves the oropharynx or the esophagus, as well as the mouth. The trachea and the larynx may also be involved where there is oral candidiasis, and this may cause hoarseness of the voice. ==Causes==

Species The causative organism is usually Candida albicans, C. albicans accounts for about 50% of oral candidiasis cases, This adhesion involves adhesins (e.g., hyphal wall protein 1), and extracellular polymeric materials (e.g., mannoprotein). Several Candida species are polymorphogenic, Immunodeficiency Immunodeficiency is a state of reduced function of the immune system, which can be caused by medical conditions or treatments. Acute pseudomembranous candidiasis occurs in about 5% of newborn infants. active cancer and treatment, chemotherapy or radiotherapy. Corticosteroid medications may contribute to the appearance of oral candidiasis, Where inhaled steroids are the cause, the candidal lesions are usually of the erythematous variety. Candidal lesions on both sites are sometimes termed "kissing lesions" These conditions all favor the growth of C. albicans. Sometimes dentures become very worn, or they have been constructed to allow insufficient lower facial height (occlusal vertical dimension), leading to over-closure of the mouth (an appearance sometimes described as "collapse of the jaws"). This causes deepening of the skin folds at the corners of the mouth (nasolabial crease), in effect creating intertriginous areas where another form of candidiasis, angular cheilitis, can develop. Candida species are capable of adhering to the surface of dentures, most of which are made from polymethylacrylate.