Oral/oropharyngeal candidiasis is not responding to standard treatment – what should I do?

We have compiled responses to the most common GP enquiries below. If you have any other questions, please contact the laboratory via email at mrcm(@)mft.nhs.uk or by phone at 0161 291 5839

A positive swab from an asymptomatic patient reflects colonisation which does not require treatment. A significant percentage of adults are colonised with Candida species, with counts fluctuating from day to day and week to week.  At the same time, symptoms of oral candidiasis are non-specific and many other infectious and non-infectious conditions present similarly. Therefore, the diagnosis has to build on the combination of symptoms, clinical findings, culture results and response to treatment.

In order to gain a better control of the recurrences, it is important to address the key risk factors:

  • poor oral hygiene
  • high carbohydrate diet
  • weak immune defenses (e.g. lack of saliva and the use of steroids and other immunosuppressants)
  • acidic environment favouring the growth of Candida (silent GORD, acidic diet)

Setting a high standard for oral hygiene is particularly important as biofilms are resistant to all antifungals. Patients should brush their teeth twice daily, floss or use an interdental brush daily, and use a tongue scraper. If they wear dentures or other appliances these need to be brushed and disinfected daily. Any oral health issues such as chronic gingivitis or periodontitis and dental caries will promote Candida growth as they harbour mixed bacterial-candidal biofilms.

Patients should also be assessed for GORD, including silent reflux. A PPI trial is recommended. Reducing alcohol, coffee and tea intake and consumption of acidic drinks and food (fizzy drinks, sour pastilles) will also help to control oral thrush.

Patients should also be advised to stay hydrated and drink enough water daily as saliva is the main defense against Candida. Medications should be reviewed, and ideally drugs causing dry mouth should be replaced.

Inhaled steroids must be used with a spacer and mouth rinsed afterwards.

Smoking cessation advice is essential.

Other or additional aetiologies for  recurring oral symptoms should be ruled out (e.g. gingivitis, hairy tongue, leucoplakia, burning mouth syndrome).

When choosing antifungal treatment, the three main factors that need to be taken into account are

  • level of saliva production
  • antifungal history (risk for azole resistance)
  • level of oral hygiene.

In patients with minimal saliva production, the levels of systemic antifungals will be very low in the oral cavity and topical antifungals are preferred. The risk for azole antifungal resistance is high in patients who have been prescribed prolonged courses of low dose (50mg OD) fluconazole, particularly if they have reduced saliva production. In these cases, topical polyenes (nystatin or amphotericin B) are a good option as polyene resistance is extremely rare. Amphotericin B lozenges are off-label but can be resourced; they are often more efficient than nystatin solution as they last in the mouth longer.

For patients whose oral hygiene is poor and is unlikely to improve, twice daily chlorhexidine mouth rinse could be considered due to its antifungal, antibacterial and antibiofilm properties. This is in contrast to many other mouth rinses with no or minimal antifungal effect which can thus promote fungal growth similarly to antibiotics. Chlorhexidine should, however, be avoided in patients with large erosive mucosal lesions due to the risk for allergic reactions.

The patient needs to be referred to an Oral Medicine specialist if the diagnosis is uncertain or microbiologically effective treatment does not resolve their symptoms.