What factors increase the risk of recurrent oral thrush in patients, and how can I address them?

Several factors increase the risk of recurrent oral thrush (oral candidiasis) in patients, including poor diabetic control, immunosuppression, use of inhaled corticosteroids, poor dental hygiene, denture use, smoking, and certain medications. Addressing these factors involves both medical management and lifestyle interventions.

Key risk factors and management strategies include:

• Diabetes: Poor glycaemic control predisposes to recurrent oral thrush. Optimising blood glucose control is essential to reduce recurrence risk ¹.
• Immunosuppression: Conditions causing immunocompromise (e.g., chemotherapy, HIV, neutropenia) increase susceptibility. Management requires specialist advice and may necessitate systemic antifungal therapy such as fluconazole ¹.
• Inhaled corticosteroids: These increase local fungal colonisation risk. Non-pharmacological interventions such as rinsing the mouth after inhaler use and proper inhaler technique can reduce risk (Arzayus-Patiño and Benavides-Córdoba, 2025) ¹.
• Denture use: Dentures can harbour Candida species, promoting infection. Regular disinfection of dentures with antiseptics like chlorhexidine, along with antifungal treatment, helps prevent recurrence ¹.
• Poor oral hygiene and smoking: Both contribute to fungal overgrowth. Improving oral hygiene practices, including regular toothbrushing with fluoride toothpaste and smoking cessation, reduces risk ¹,².
• Drug interactions and medications: Some antifungals interact with drugs like sulfonylureas, warfarin, and statins, complicating treatment. Careful medication review and choice of antifungal (e.g., nystatin instead of miconazole in statin users) are important ¹.

Additional management considerations: If oral thrush is recurrent or resistant to treatment, swabbing to identify causative organisms and specialist referral should be considered to exclude resistance or alternative diagnoses ¹. For denture-related candidiasis, combining antifungal treatment with denture disinfection is recommended ¹.

In summary, recurrent oral thrush risk is multifactorial, involving systemic conditions, local factors, and medication effects. Addressing these through optimising systemic disease control, improving oral hygiene, managing denture care, and modifying inhaler use can reduce recurrence. Specialist input is warranted in complex or resistant cases ¹ (Arzayus-Patiño and Benavides-Córdoba, 2025).