Oral thrush is often over-diagnosed in the immuno-competent. Prescribing is only recommended where symptomatic thrush has been identified. Oral thrush tends to be more problematic in some patients e.g. cancer patients, other immunocompromised patients, and those on corticosteroids.

Failure to respond to treatment (particularly in the immuno-compromised) may indicate mouth ulceration due to herpes. Swabs may be helpful in the case of treatment failure; requests must include details of agents that have not been successful.

Fungal infections of the mouth are usually caused by Candida spp. (candidiasis or candidosis). Underlying conditions, medications or devices which predispose to infection should also be managed in order to optimize the chances of successful treatment.

Acute infections should normally resolve with good oral hygiene and topical treatment.

Managing risk factors for developing oral candidiasis

Dentures or orthodontic braces with plates:

• Good oral hygiene and thorough washing of teeth/brace to eliminate source of infection
• Advise patient to sleep without teeth/brace if possible
• Miconazole gel may be applied to the underside of the plate if patient is unable to go without wearing teeth/brace at any time

Smoking:

• Encourage patients to think about stopping, offer smoking cessation products if needed

Antibacterial therapy:

• Assess continuing need for antibacterial therapy and stop if appropriate

If possible, eliminate or manage any precipitating factors for candidiasis alongside prescribing treatment for the infection.

Mild Acute Infection

Nystatin oral suspension 100 000 units/ml

• 1ml four times daily for 7 days with continuation for at least 48 hours after symptoms have disappeared
• If signs and symptoms worsen or persist beyond 14 days of treatment, the patient should be re-evaluated, and alternate therapy considered
• It is important that the dose remains in contact with the affected area for as long as possible. Divide administration of the dose between both sides of the mouth
• Since the absorption of nystatin from the gastro-intestinal tract is negligible, overdose or accidental ingestion causes no systemic toxicity
• Dentures must be removed when nystatin is used to ensure all of the mouth is coated. Dentures can be soaked in a sodium hypochlorite solution (e.g. Milton® or Dentural®) for 20 minutes, rinsed and air-dried.

Miconazole oral gel 24 mg/ml

• Adults and children 2 years of age and older:
  
  • 2.5ml four times a day after meals
• Infants:
  
  • 4 months – 2 years: 1.25ml four times a day after feeds. The gel should not be applied to the back of the throat due to possible choking. The lower age limit should be increased to 5-6 months of age for infants who are pre-term, or infants exhibiting slow neuromuscular development
• The treatment should be continued for at least a week after lesions have healed or symptoms have cleared
• Each dose should be divided into smaller portions and the gel should be applied to the affected area(s) with a clean finger
• Dental prostheses should be removed at night and brushed with the gel
• The gel should not be swallowed immediately, but retained in the mouth for as long as possible near the lesions

Miconazole greatly enhances the anti-coagulation effect of warfarin, avoid concomitant use. Refer also to MHRA Drug Safety Update (June 2016).

Refer to the BNF or manufacturer's Summary of Product Characteristics (SPC) for a full list of interactions with miconazole.

Severe Acute, or Chronic Infection

Oropharyngeal candidiasis:

Acute oropharyngeal candidiasis presents as a speckled white "cream cheese" deposit on mucosal surfaces around the mouth and throat which may be associated with discomfort or difficulty swallowing.

Fluconazole

• Adults and children over 12 years of age:
  
  • 50mg daily for 7-14 days
• Children under 12 years of age:
  
  • Refer to BNFC

Oesophagitis:

Fluconazole

• Adults and children over 12 years of age:
  
  • 50mg daily for 14-30 days, dose may be increased to 100mg daily for unusually difficult infections
• Children under 12 years of age:
  
  • Refer to BNFC

Notes

1. Usual initial dose then halve subsequent doses if eGFR less than 50 mL/minute/1.73 m²
2. Be aware of potential drug interactions as a result of inhibition of various cytochrome P450 enzymes by azole antifungals
3. Higher doses and longer courses may be needed in immunosuppressed patients, and patients with more severe infections