Oral mycoses
Introduction:
Oral mycoses are opportunistic infections, caused by saprophytic germs and are always the sign of an imbalance in the oral flora, the etiology of which must be determined.
They have increased considerably in recent years, due to three main factors:
- Prolongation of survival of patients at risk: Cancer patients, transplant patients, acquired immunodeficiency syndrome.
- reduction in mortality due to microbial infections.
- Intercontinental travel leads to the importation of cosmopolitan mycoses.
- Pathogenicity factors of fungi:
Adhesion factor:
The fungus adheres to skin and mucosal surfaces through interactions between fungal cell wall constituents and host receptors.
The adhesion of candida albicans to plastic and acrylic explains the colonization of prostheses, catheters, etc.
Secretion of enzymes:
Some strains of Candida secrete proteolytic enzymes that destroy organic matter and promote tissue invasion.
Secretion of toxins:
Aspergillus fumigatus secretes immunosuppressive toxins that are hemolytic or participate in host cell death.
Spore structure:
The structure of the wall of certain spores protects them from phagocytes.
II. Factors promoting oral mycoses:
Intrinsic factors:
- Physiological: Age, pregnancy;
- Local: hyposialia, xerostomia, maceration under plaque, trauma, burns, etc.
- Endocrine terrain: Diabetes
- Nutritional deficiencies: Iron deficiency
- Immunosuppression: AIDS
- Intercurrent infectious or malignant conditions: cancer, blood disease, bone marrow aplasia, etc.
Extrinsic factors:
- Mainly iatrogenic
- Medications: antibiotics, corticosteroids, immunosuppressants, contraceptive hormones, cervicofacial radiotherapy, anti-cancer chemotherapy.
- III. The different oral mycoses:
- A classification of the main species responsible for oral mycoses can be proposed, distinguishing yeasts, filamentous fungi, and exotic fungi.
a) Yeasts:
Candida albicans:
- It is the most common etiological agent
- Lives in a saprophytic state in the digestive tract;
- Present in the first months of life and transmitted through maternal contact;
- It exists in three biological and morphological forms.
Its dissemination is of endogenous origin and occurs from the digestive tract.
Oral mycoses
Cryptococcosis:
It includes 19 different species, only Cryptococcus neoformans is pathogenic due to its growth temperature above 37°C.
Contamination occurs through the respiratory tract and dissemination is via the blood or lymphatic system in order to reach the mucous membranes.
b) Filamentous fungi:
Mucorales:
They belong to the class of zygomycetes
They are cosmopolitan
Contamination occurs through inhalation of spores, it develops exclusively in immunocompromised patients: AIDS, diabetes, etc.
Extrapulmonary Aspergillus:
cosmopolitan fungus common in the environment, they live off decomposing organic matter.
Human contamination occurs through inhalation,
In healthy subjects, they are most often promoted by the obturation of the endocanal systems with zinc oxide pastes.
c ) Exotic mycoses:
These are diseases whose causative agent does not exist in Europe, the observed cases are imported from hot and humid regions, the fungi live in a saprophytic state in the soil, the contamination is most often pulmonary by inhalation, or cutaneous by traumatic inoculation. Among the exotic mycoses we find: histoplasmosis, paracoccidiomycosis, and coccidiomycoses.
III. Clinical forms of oral mycoses
III.1) acute candidiasis:
- Pseudomembranous form or thrush:
- burning sensation,
- Sensation of metallic taste or dry mouth followed by the appearance of red macules, creating diffuse erythematous stomatitis.
- The gum is most often respected;
- Appearance around the 2nd day of more or less thick whitish efflorescences which will merge.
- Scraping with a tongue depressor easily removes them without bleeding of the mucous membranes.
- Minimal symptoms, complete recovery after treatment.
- The differential diagnosis is made with lichen planus, tobacco leukoplakia, or even squamous cell carcinoma.
Oral mycoses
b) Acute atrophic form:
- This is a diffuse depapillative glossitis;
- Most often due to taking broad-spectrum antibiotics or a combination of antibiotics,
- The clinical signs are more marked, because there are numerous erosions on an intense inflammation
Oral mycoses
III.2) chronic candidiasis
- Chronic atrophic forms:
- Appear in elderly people with removable prostheses,
- The clinical appearance is a bright red area with a velvety surface and slightly keratinized mucosa;
- Median rhomboid glossitis:
- It is a roughly diamond-shaped erythematous area in front of the lingual V,
- It is smooth, flat or hummocky,
- Opposite this median diamond-shaped area, we find a mirror-shaped palatine lesion made up of small erythematous macules.
- Angular cheilitis or angular cheilitis:
- Found at the level of the labial commissure;
- It extends towards the retrocommissural slope and the internal face of the cheek.
- It can be isolated or associated with other forms of chronic candidiasis;
Oral mycoses
- The black hairy tongue:
- Special form of glossitis
- Due to hypertrophy of the filiform papillae taking on a brown or even black tint through oxidation of the keratin;
- It is most often wrongly classified as a mycoses,
- The search for candida is most often negative, and it resists classic antifungal treatments,
- Mycological culture sometimes finds candida geotrichom without its pathogenic role being confirmed.
III.3) deep mycoses of the oral cavity:
- cryptococcosis:
- Common in HIV-infected patients
- It is responsible for life-threatening lung infections and meningoencephalitis;
- Oral lesions are rare, and when they exist, they appear as vegetating, purplish papules or nodules that may become necrotic.
b) mucormycosis:
- Fungal infection preferentially affecting poorly controlled diabetic patients and those with immunodeficiencies,
- The front door is respiratory;
- From the nasal involvement, the extension can also occur downwards towards the bony palate.
Oral mycoses
- Nasal sinus aspergillosis:
- Located in the maxillary sinus;
- In the majority of cases, it is of dental etiology.
- Sinusitis can be acute or chronic, manifesting as fever with or without signs of sinusitis or rhinitis,
- Unilateral symptoms and chronic pain suggest the diagnosis.
Unilateral aspergillotic sinusitis due to excess zinc oxide eugenol paste into the sinus
IV. Positive diagnosis of oral mycoses:
- Essentially based on a specific mycological examination;
- The sample is taken by swabbing the lesions.
- Diagnosis is based on the search for fungal elements in the lesions;
- The diagnosis of oral mycosis is based on the comparison of clinical and paraclinical data; it is necessary to remain critical of the results of the cultures due to the saprophytic presence of candida in the oral cavity.
V. Treatment of oral mycoses:
The main treatment is based on antifungals;
Two main families are used for the treatment of mycoses
Polyenes:
Amphotericin B (Fungizone): administered orally, it does not cross the digestive mucosa, its antifungal spectrum is broad,
Nystatin (Mycostatin): this antifungal has almost zero digestive absorption, which makes it a treatment of choice for oral mycoses extending to the rest of the digestive tract.
Azole derivatives:
Myconazole (Daktarin): Topical application
Ketokonazole (Nizoral): reserved for severe oral mycoses, it remains hepatotoxic, and contraindicated in pregnant women
Triazoles:
Fluconazole (Trifulcan): used orally or systemically, is very active against most yeasts, it is contraindicated during pregnancy, and interferes with several medications: anticoagulants, diuretics, cyclosporine, rifampicin.
Conclusion :
Oral mycoses are manifested by whitish lesions of the oral mucosa, the diagnosis is essentially clinical, however a lack of knowledge of the manifestations of these lesions can lead to a diagnostic or even therapeutic error.
Oral mycoses
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Preventative dental care avoids costly treatments.
Baby teeth serve as a guide for permanent teeth.
Fluoride mouthwash strengthens tooth enamel.
An annual checkup helps monitor oral health.