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Oral Yeast Infections
Essentials
- Fungal infections in the mouth are almost exclusively caused by the yeast Candida albicans. It is a normal oral parasite and is found in the oral cavity of as many as 20-50% of symptomless individuals.
- Clinical yeast infection, i.e. candidiasis, develops when the host's resistance is impaired and the natural balance of the oral flora becomes disturbed. Yeast infection is therefore a sign of either a local or systemic impairment of the host's resistance.
- Local predisposing factors include the lack of normal bacterial flora in newborn babies, poor oral hygiene in denture wearers, reduced salivation, smoking and inhaled glucocorticoids.
- Systemic predisposing factors include antibiotics, diabetes, Down syndrome Down's Syndrome, APECED (autoimmune polyendocrinopathy-candidosis-ectodermal dystrophy Apeced (Autoimmune Polyendocrinopathy - Candidiasis - Ectodermal Dystrophy)), advanced cancer, immunodeficiency, immunosuppressive therapy and radiotherapy around the salivary gland area.
Clinical manifestation
- In clinical practice yeast infections of the mouth are considered to be either primary or secondary.
- Primaryyeast infections can be acute, chronic, associated with candidal infection or they may be keratinised lesions superinfected by yeast infection.
- The most common form of the acute infections is the erythematous type where mildly painful diffuse reddish areas of varying size are seen on the oral mucosa. The acute pseudomembraneous type (oral thrush) is characterised by light-coloured patches that coat the oral mucosa to varying extent and that can be scraped off.
- A chronic candidiasis may be either erythematous or pseudomembraneous (picture 1). Additionally, it also manifests itself as yeast infections with hyperplastic, nodular or plaque-like appearance that cannot be scraped away.
- Conditions associated with candidal infection are denture stomatitis, angular cheilitis (picture 2) and median rhomboid glossitis (see Benign Lesions of the Tongue; picture 3).
- Keratinised lesions often superinfected by yeast infection include leucoplakia, lupus erythematosus Assessment of Oral Mucosal Changes and oral lichen planus Oral Lichen Planus.
- Secondary oral yeast infections refer to mucocutaneous infections caused by a systemic illness.
Diagnosis
- Diagnosis can sometimes be made on the basis of a typical clinical picture, but often a laboratory test is needed.
- Fungal culture sample from the oral mucosa. The sample is collected to a gel-containing transport tube (e.g. Transpocult® ) ordered from the microbiology laboratory. The patient may also visit the laboratory for sample taking.
- The culture report indicates the fungal species found and their quantities on a plus scale (+, ++, +++). Two or three pluses suggest an infection to be treated. The symptoms and clinical findings should, however, be taken into account when making treatment decisions.
- A cytologic specimen can be taken from a lesion or from the oral mucosa on a microscope slide. It is fixed with alcohol or a special fixative and sent directly to the pathology laboratory for examination.
- If there is a need to take a biopsy, it can be examined with PAS staining for possible candidal infection.
Treatment
- If only possible, treatment is always based on the elimination of local and systemic factors that predispose the patient to candidal infections.
- In patients wearing dentures, rebasing or renewal of these should be considered. Dentures should be daily brushed using e.g. a dishwashing liquid, taken out of the mouth for the night and stored dry.
- During the antifungal medication, the dentures should be disinfected daily, then once a week.
- Possible disinfectant agents to be used: 0.2% chlorhexidine solution, 0.02% sodium hypochlorite solution, or effervescent denture cleansing tablets. After 15-30 min of disinfection the dentures are carefully rinsed with water.
- Drug therapy is prescribed if the clinical signs are suggestive of yeast infection and the patient is symptomatic, e.g. has stinging, burning or tenderness of the mouth. It is advisable to confirm the diagnosis also with culture or from a cytologic specimen / biopsy.
- Topical drug therapy (the most recommended) Ehttp://www.dynamed.com/condition/oral-candidiasis#MANAGEMENT_RECOMMENDATIONS; treatment is continued for at least one week after the symptoms have disappeared (the prescription can be written for e.g. 4 weeks)
- Nystatin oral suspension (100 000 IU/ml) 1 ml 4 times daily. The dose can be increased as necessary.
- Miconazole 20 mg/g or 2% oral gel, 2.5 ml every 6 hours
- Note the possibility of drug interactions (e.g. with warfarin) in association with the use of miconazole gel!
- Amphotericin B 10 mg lozenges, 1 tablet 4 times daily
- Systemic drug therapy (recommended for prophylaxis Preventing Oral Candidiasis in Cancer Patients in patients receiving cancer treatment; may also be somewhat more effective in the treatment Treating Oral Candidiasis in Cancer Patients of oral yeast infections)
- Primarily fluconazole 200-400 mg once on the first day, then 100-200 mg once daily for 1-2 weeks
- In patients receiving treatment for cancer the doses may be larger and the duration of treatment longer. For prophylaxis in cancer patients 200-400 mg once daily.
- If there is no response to fluconazole, it is recommended to take a specimen for antifungal drug sensitivity testing and to plan further treatment accordingly.
- Note: azole antifungal agents may have harmful interactions with a number of other drugs, e.g. warfarin. The risk of azole resistance has to be taken into account when treating recurrent oral candidiasis.
References
- Hellstein JW, Marek CL. Candidiasis: Red and White Manifestations in the Oral Cavity. Head Neck Pathol 2019;13(1):25-32. [PubMed]
- Pappas PG, Kauffman CA, Andes DR et al. Clinical Practice Guideline for the Management of Candidiasis: 2016 Update by the Infectious Diseases Society of America. Clin Infect Dis 2016;62(4):e1-50. [PubMed]
- Pankhurst CL. Candidiasis (oropharyngeal). BMJ Clin Evid 2013;:1304. [PubMed]