Clinical clangers: ‘My test results say I’ve got thrush – can I get a prescription, doctor?’

Dr Toni Hazell outlines how to advise a patient with an incidental finding of Candida, and why a prescription is not always necessary

A 25-year-old woman presents with intermenstrual bleeding. She has no other symptoms. As part of the assessment, the GP takes a set of swabs, which come back largely normal apart from a moderate growth of Candida albicans. The patient then sees the results via online access to her notes and requests a prescription for thrush treatment. 

The reality
Asymptomatic thrush does not need to be treated.

The issue
Any test risks throwing up an incidental finding and if we are not careful, this can lead to overdiagnosis and overtreatment. The phenomenon is so common that the term ‘incidentaloma’ has been coined to describe incidental scan findings and whole protocols have been written for how to deal with them.¹ As GPs we need to have the confidence to tell our patients when something is incidental and doesn’t need treating. 

The evidence 
Up to 20% of women may have asymptomatic Candida albicans colonisation detected on swabs done for another reason; the prevalence increases to 30-40% during pregnancy.^2,3 The British Association for Sexual Health and HIV (BASHH) defines acute vulvovaginal candidiasis as a ‘first or single isolated presentation… patients typically present with signs and symptoms of acute vulvovaginitis and Candida species can be detected by microscopy or cultures’.³ The guideline about how to treat therefore does not apply to those with no symptoms. 

NICE CKS comments that asymptomatic Candida does not need treatment;² Candida is often part of normal vaginal flora.⁴ Avoiding the taking of unnecessary swabs can also help to reduce overdiagnosis and treatment, as well as reducing healthcare costs. 

Pregnant women who have asymptomatic thrush may be keen to access treatment, but the BASHH guidelines state that there is no link between asymptomatic thrush in pregnancy and outcomes such as prematurity or low birth weight, and this is confirmed by a recent systematic review and meta-analysis.⁵ Pregnant women can therefore also be reassured that they do not need treatment. 

Caveats 
It is possible that a patient may not volunteer symptoms of thrush, especially when consulting for another reason. Also, the reality of primary care is that we might not always know why swabs have been done. GPs are sometimes sent swabs taken by other healthcare professionals, such as midwives (although in an ideal world the professional who takes the swab would always follow up the result). One simple way to deal with this is to contact the woman to find out if she is symptomatic or not. If workload precludes this, on a routine basis women can be asked to go online or phone for their results and the result should be marked ‘thrush – needs treatment only if there are symptoms of itch or discharge’. The woman can then alert the practice if she is symptomatic so that a prescription or advice to obtain medication from a pharmacy can then be issued.

References