From the Guidelines
Oral thrush is primarily caused by an overgrowth of the fungus Candida albicans in the mouth, often associated with immune dysfunction, as seen in HIV infection, diabetes, leukemia, and other malignancies, as well as steroid use, radiation therapy, antimicrobial therapy, and denture use 1.
Causes of Oral Thrush
The causes of oral thrush can be multifactorial, including:
- Immune system dysfunction, such as in HIV-infected patients, particularly those with CD4 counts <200 cells/μL 1
- Diabetes
- Leukemia and other malignancies
- Steroid use
- Radiation therapy
- Antimicrobial therapy
- Denture use, especially if poorly fitted or inadequately cleaned
Risk Factors
Certain populations are at a higher risk of developing oral thrush, including:
- Infants
- Elderly individuals
- Patients with weakened immune systems
- Those with dry mouth conditions
- Individuals with poor oral hygiene
- Smokers
- People with high-sugar diets
Prevention and Treatment
Preventing oral thrush involves addressing underlying causes and maintaining good oral hygiene. Treatment typically involves antifungal medications, such as fluconazole or itraconazole solution, which have been shown to be effective in managing oropharyngeal candidiasis 1. Fluconazole is a recommended treatment option, with a dosage of 200 mg on day 1, then 100 mg daily for 1-2 weeks, as it has been shown to be effective in preventing oropharyngeal candidiasis and reducing the relapse rate 1.
From the Research
Causes of Oral Thrush
The causes of oral thrush can be attributed to various factors, including:
- Overgrowth of Candida species, particularly Candida albicans, in the oral cavity 2, 3, 4
- Impaired salivary gland function 2
- Use of drugs, such as antibiotics and immunosuppressive agents 2, 5, 6
- Wearing dentures 2
- High carbohydrate diet 2
- Extremes of life, such as old age or infancy 2
- Smoking 2, 5
- Diabetes mellitus 2, 5
- Cushing's syndrome 2
- Malignancies 2
- Immunocompromised conditions, such as HIV/AIDS 3, 5, 6
- Xerostomia (dry mouth) 5
- Alcohol consumption 5
- Advanced HIV clinical stage (AIDS) 5
- Low CD4 count 5
Risk Factors
Certain individuals are more prone to developing oral thrush due to various risk factors, including:
- Age 2, 5
- Sex 5
- Immunocompromised status 2, 3, 5, 6
- Use of prosthetics, although no significant association was found in one study 5
- Antibiotic usage 5
Fungal Diversity
The oral mycobiota of patients with oral thrush has been found to have low alpha diversity and varied beta diversity, with an increased relative abundance of C. albicans 3. This suggests that the fungal diversity in the oral cavity plays a role in the pathophysiology of oral thrush.