The incidence of C. The additional important species isolated from clinical infections include, C. In recent years higher incidences of the above mentioned non- C. TABLE 1. Oral carriage of Calbicans albicans in various subjects Akpan and Morgan, In addition to C. Salivary gland dysfunction predisposes to oral candidiasis. Constituents of saliva such as histidine-rich polypeptides, lactoferrin, lysozyme, and sialoperoxidase inhibit the overgrowth of candida.
Hence, conditions affecting the quantity and quality of salivary secretions may lead to an increased risk of oral candidosis Scully et al. TABLE 2. Factors predisposing for oral candidiasis Rautemaa and Ramage, Dental prostheses creates a favorable microenvironment for the candida organisms to thrive. The possible explanations include enhanced adherence of candida to the acrylic, ill-fitted appliances, decreased saliva flow under the denture surfaces or inadequate hygiene Ashman and Farah, ; Martori et al.
Another important local factor increasing the risk of oral candidosis could be use of topical or inhalational corticosteroids and overzealous use of antimicrobial mouthwashes. They temporarily suppress the local immunity and cause alterations in the oral flora Scully et al. Some studies suggest that smoking alone or in combination with other factors, significantly affects the oral candida carriage while few studies propose otherwise Soysa and Ellepola, ; Barnett, ; Munshi et al.
The precise mechanism is not established but various theories have been postulated. The possible explanations facilitating candida colonization include localized epithelial alterations caused by smoking Arendorf and Walker, ; smoking in association with denture friction altering the mucosal surface Arendorf and Walker, ; nutritional products obtained through enzymatic breakdown of aromatic hydrocarbons contained in cigarette smoke Hsia et al.
Unbalanced dietary intake of refined sugars, carbohydrates and dairy products containing high content of lactose might serve as growth enhancers by reducing the pH levels and hence favoring the candida organisms to thrive Martins et al. Extremes of age may predispose to candidiasis due to immature or weakened immunity Weerasuriya and Snape, Among the nutritional deficiency states, iron has been the most common deficient essential micronutrient implicated in the colonization of candida.
Deficiency of iron diminishes the fungistatic action of transferrin and other iron-dependant enzymes. In addition, other nutrients frequently deficit in chronic candidiasis includes essential fatty acids, folic acid, vitamins A and B6, magnesium, selenium, and zinc Paillaud et al. Prolonged use of systemic drugs like broad-spectrum antibiotics, immune-suppressants and drugs with xerostomic side-effects, alter the local oral flora or disrupt mucosal surface or reduce the salivary flow, creating a favorable environment for candida to grow Martins et al.
Escalation in candida organisms has also been reported in patients undergoing radiation therapy to the head and neck region. The host defense mechanisms are compromised by chemotherapy and radiotherapy administered for the treatment of malignant conditions. The prevalence of oral candidiasis for all cancer treatments, according to a systematic review, was reported to be 7.
The prevalence of oral candidiasis during head and neck radiation therapy and chemotherapy was observed to be The colonization by C.
This form of candidiasis classically presents as acute infection, though the term chronic pseudomembranous candidiasis has been used to denote chronic recurrence cases. It is commonly seen in extremes of age, immunocompromised patients especially in AIDS, diabetics, patients on corticosteroids, prolonged broad-spectrum antibiotic therapy, hematological, and other malignancies Figure 1.
On the oral surfaces, the superficial component presents as white to whitish-yellow creamy confluent plaques resembling milk curds or cottage cheese. These plaques consist of desquamated epithelial cells, tangled aggregates of fungal hyphae, fibrin, and necrotic material Lalla et al. The superficial pseudo-membrane can be removed by wiping gently, leaving behind an underlying erythematous and occasionally bleeding surface Ashman and Farah, ; Farah et al.
The oral surfaces frequently involved include labial and buccal mucosa, tongue, hard and soft palate and oropharynx. The involvement of both oral and oesophageal mucosa is prevalent in AIDS patients. The symptoms of the acute form are rather mild and the patients may complain only of slight tingling sensation or foul taste, whereas, the chronic forms may involve the oesophageal mucosa leading to dysphagia and chest pains.
Few lesions mimicking pseudomembranous candidiasis could be white coated tongue, thermal and chemical burns, lichenoid reactions, leukoplakia, secondary syphilis and diphtheria Lalla et al. TABLE 3. Classification of oral candidosis Axell et al. Pseudomembranous candidiasis of the tongue. The copyright of the images is owned by Prof. Anil and a written consent was obtained for the Figures 1 — 6.
Erythematous candidiasis is relatively rare and manifests as both acute and chronic forms Ashman and Farah, The chronic form is usually seen in HIV patients involving the dorsum of the tongue and the palate and occasionally the buccal mucosa Figure 2. Clinically, it manifests as painful localized erythematous area. It is the only form of candidiasis associated with pain. The lesions are seen on the dorsum of the tongue typically presenting as depapillated areas.
Palatal lesions are more common in HIV patients. Differential diagnosis may include mucositis, denture stomatitis, erythema migrans, thermal burns, erythroplakia, and anemia Dodd et al. The hyperplastic candidiasis mainly presents as chronic form. The lesions usually occur bilaterally in the commissural region of the buccal mucosa and less frequently on the lateral border of the tongue and palate Figure 3. Unlike the pseudomembranous type, hyperplastic candidiasis lesions are non-scrapable.
There appears to be a positive association with smoking and in addition may present with varying degrees of dysplasia Williams and Lewis, A confirmed association between Candida and oral cancer is yet to be recognized, although in vitro studies have shown that the candida organisms can generate carcinogenic nitrosamine Farah et al.
A small percentage of cases occur in association with iron and folate deficiencies and with defective cell-mediated immunity. Differential diagnosis may include leukoplakia, lichen planus, angular cheilitis and squamous cell carcinoma.
It occurs frequently along with angular cheilitis and median rhomboid glossitis. The lesions are usually asymptomatic, though occasionally patients may complain of burning sensation or soreness. It commonly affects the palate although mandibular mucosa may also be affected Figure 4.
The associated etiological factors include poor oral hygiene practice, nocturnal denture wear, ill-fitting prostheses and limited flow of saliva Farah et al. This form of candidiasis usually manifests as erythematous or ulcerated fissures, typically affecting unilaterally or bilaterally the commissures of the lip Samaranayake et al.
The factors associated include old age and denture-wearers due to reduced vertical dimension , vitamin B12 deficiency and iron deficiency anemia Jenkins et al. Other causative organisms implicated are Staphylococcus and Streptococcus Farah et al.
Median rhomboid glossitis appears as the central papillary atrophy of the tongue and is typically located around the midline of the dorsum of the tongue. It occurs as a well-demarcated, symmetric, depapillated area arising anterior to the circumvallate papillae Figure 5.
The surface of the lesion can be smooth or lobulated Joseph and Savage, While most of the cases are asymptomatic, some patients complain of persistent pain, irritation, or pruritus Lago-Mendez et al. The lesion is now believed to be a localized chronic infection by C. It is commonly seen in tobacco smokers and inhalation-steroid users Aun et al.
It manifests as linear erythematous band of 2—3 mm on the marginal gingiva along with petechial or diffuse erythematous lesions on the attached gingiva. The lesions may present with bleeding. This group is characterized by chronic mucocutaneous candidiasis, which consists of heterogeneous disorders, presenting as persistent or recurrent superficial candida infections of the mouth, skin, nail beds, and occasionally producing granulomatous masses over the face and scalp.
The primary clinical features include chronic oral, cutaneous and vulvovaginal candidiasis. Oral candidiasis in neonates is reported to be 0. The most common form of candidiasis affecting this age group is the acute pseudomembranous candidiasis Berdicevsky et al. Candida species isolated from these lesions include C.
Majority of the lesions are asymptomatic. They mainly present as white scrapable pseudomembranous lesions. The major predisposing factors were low birth weight, prolonged hospital stay and associated increased risk of exposure to environmental factors. In case of invasive or disseminated candidiasis, systemic interventions are obligatory Sitheeque and Samaranayake, An effective management of oral candidiasis can be achieved by adhering to the following simple guidelines:.
Diagnosis of oral candidosis, includes identification of clinical signs and symptoms, presence of the candida organisms on direct examination of a smear from the lesion or biopsy examination showing hyphae in the epithelium, positive culture, and serological tests Rossie and Guggenheimer, ; Ellepola and Morrison, Another concern with respect to the treatment, is the increase in NCAC species which are naturally resistant to some of the common antifungal drugs Table 4.
For example, in HIV positive cases there is reported increase in C. TABLE 4. Susceptibility of C. Antifungal agents that are available for the treatment of candidosis fall into three main categories: the polyenes nystatin and amphotericin B ; the ergosterol biosynthesis inhibitors-the azoles miconazole, clotrimazole, ketoconazole, itraconazole, and fluconazole , allylaminesthiocarbamates, and morpholines; and DNA analog 5-fluorocytosine, and newer agents such as caspofungins Ghannoum and Rice, ; Pappas et al.
The choice of antifungal treatment depends on the nature of the lesion and the immunological status of the patient.
There are three main antifungal drug targets in Candida : the cell membrane, cell wall, and nucleic acids Figure 7 Cannon et al. Cellular targets of antifungal agents. The antifungal agents target three cellular components of fungi. Azoles inhibit the synthesis of ergosterol in the endoplasmic reticulum of the fungal cell. Polyenes such as amphotericin B bind to ergosterol in the fungal membrane causing disruption of membrane structure and function.
Flucytosine is converted within the fungal cell to 5-fluorouracil which inhibits DNA synthesis. Superficial oral candidosis in generally healthy patients can be treated topically and oral candidosis in immunocompromised patients should be treated systemically as well as topically.
Patients with persisting risk factors and relapsing candidosis should be treated with antifungals with the lowest risk of development or selection of resistant strains Soysa et al. The commonly used antifungal agents in the management of OPC is listed in Table 5.
TABLE 5. Treatment of oropharyngeal candidiasis OPC; Thompson et al. Topical antifungals are usually the drug of choice for uncomplicated, localized candidiasis in patients with normal immune function. High levels can be achieved in the oral epithelium with topically administered antifungals. Polyenes are fungicidal drugs that act through direct binding to the ergosterol within the fungal cell membranes, inducing leakage of cytoplasmic contents leading to the fungal cell death.
Nystatin or amphotericin B solutions are used for 4 weeks. In recurrent cases the duration of treatment should be for at least 4—6 weeks. Topically administered miconazole gel is also suitable for the treatment of uncomplicated infections in generally healthy patients Bensadoun et al. It should also be used for 1 week after resolution of symptoms. The gel inhibits the action of fungal ergosterol synthesis; interacts with the cytochrome P enzyme alpha demethylase; inhibits growth of pathogenic yeasts by altering cell membrane permeability.
Repeated use of miconazole, however, may cause a risk of development of azole-resistant strains Rautemaa et al. Azoles are fungistatic drugs that inhibit the fungal enzyme lanosterol demethylase responsible for the synthesis of ergosterol.
Among the azoles, fluconazole attains a higher concentration in the saliva making it principally the suitable drug for treating this oral infection. Infections of the mouth, throat, and esophagus. Global Emergence of Candida auris. Learn more about C. Enter your email to get updates on C. What's this? Related Links. Links with this icon indicate that you are leaving the CDC website. Linking to a non-federal website does not constitute an endorsement by CDC or any of its employees of the sponsors or the information and products presented on the website.
He was able to reproduce the infection in healthy children and thereby confirmed his hypothesis that the fungus caused the infection 2. After this discovery, other infections would be ascribed to this dimorphic fungus including vaginitis and gastrointestinal candidiasis. Once the etiology was conclusively demonstrated by mycologists, the next point of contention was the identity of the pathogen.
While Langenbeck first documented the fungus associated with thrush, he failed to make the direct connection. Hill 4 and later Martin and Jones 8 misclassified Candida into the genus Monilia, a genus containing fungi that commonly grow in plants.
Christine Berkhout and others noted these differences, particularly the ability of this fungus to infect humans. Berkhout reclassified it under the current genus Candida 1. Candida is derived from Latin where toga candida was a white robe worn by Roman Senators. However, it was not until that the Eighth Botanical Congress officially endorsed the binomial Candida albicans as the nomen conservandum formally ending the year long uncertainty over the etiology and taxonomy of Candida.
Currently, there are some organism species within the genus Candida. These yeast-like cells are anamorphic sexual imperfect fungi belonging to the form-class Blastomycetes.
They are characterized by their polymorphic nature and ability to produce budding yeast cells blastoconodia , mycelia, pseudomycelia, and blastospores 3. Of the nearly species, six species, C.
0コメント