Associate Professor Leo Leader is one of the most experienced Obstetricians and Gynaecologists in Sydney and has been practicing and teaching for over 35 years.
He holds an appointment in the School of Women’s Health, Faculty of Medicine, UNSW. He has recently retired from a role as a senior consultant obstetrician and gynaecologist at the Royal Hospital for Women, Sydney.
Recently a 30-year-old patient attended my clinic with a three-month history of recurrent vagina “Thrush”. This was treated by her GP. The story was typical with a history of persistent intense vaginal itching and a white creamy discharge.
The first two episodes were treated with Clotrimazole. The first with a single dose pessary and the second time with 3-day course of vaginal Clotrimazole cream. Now that it had re-occured for the third time, she was referred for a specialist opinion.
The patient didn't think that any diagnostic tests were taken. Yes, she was sexually active with the single regular partner. He had not been treated.
Diagnostic considerations
In this situation a healthcare professional should consider a few other factors as well:
- Did the patient have a recent antibiotic treatment?
- Is the patient immunocompromised or has an auto immune disease?
- Is the patient on a treatment from infections such as HIV or on chemotherapy?
- Diabetes must be excluded, use urine dipstick test for sugar.
- Other factors that may change the vaginal environment are pregnancy, oral contraceptives or menopause hormone treatment (MHT).
Following these considerations, a careful vaginal examination should be done after explaining what you need to do and why. Permission should be obtained.
Vaginal examination
Vulva
Exclude the presence of skin dystrophic changes or Human Papilloma virus that could also cause itching. Check when her most recent cervical screening test was done.
Vagina
Look for presence and characteristic of the discharge. Exclude possibility of bacterial vaginosis.
Cervix
Look for an evidence of cervicitis.
Uterus
Look for enlargement and tenderness.
Adnexa
Exclude tenderness and masses.
Vaginal samples
After the examination, take 2 vaginal samples, one for culture and one for making a wet preparation. Take an additional cervical swab for a PCR to test for Chlamydia and Gonorrhoea as they are usually done in tandem.
Take the wet preparation swab and add a drop of the discharge to each of two glass microscope slides. Add a drop of saline to the first to make a saline preparation. To the second slide, add a drop of 10% KOH. Adding this to the vaginal sample in the presence of Gardnerella vaginalis releases an amine which has a fishy odour. This is known as a positive Whiff test. The KOH also lyses the inflammatory and epithelial cells making any fungus more visible under the microscope.
Problem with recurrence
One of the main reasons that thrush (caused by Candida, Monilia) can recur is due to the formation of spores. Unfortunately, all the forms of treatment are only active against the mycelia (or hyphae, which is body of the fungus). The only effective way of killing spores is by boiling water (i.e., heat). These spores will hatch when conditions become favourable which is usually pre-menstrually when the vaginal pH becomes less acidic. The process is enhanced during menstruation as blood is a very good culture medium.
Treatment
The best treatment option provided infection due to Candida albicans would be oral Fluconazole 150 mg as single dose. This should be repeated monthly for the next 3 to 6 months just pre-menstrually to kill off any new mycelial growth from spores that have started to grow again and will lead to reinfection.
The patient may also become reinfected by her partner who may have either a local penile infection or some spores on his penis. A partner can be completely asymptomatic. The best way to deal with this is for the partner to either apply a local antifungal cream nightly such as Miconazole 2% cream for seven nights or a Fluconazole 150 mg tablet as a single dose. This may need to be repeated if their partner gets a reoccurrence of her infection, and they are having unprotected sex.
Another option to reduce the likelihood of reinfection would be the use of a vaginal probiotic. Repopulating the vaginal flora with lactobacilli has been shown to reduce the likelihood of recurrence.
Should the culture grow different form of Candida such as Candida glabrata, then the treatment would need to be changed as this form of Candida is resistant to local Clotrimazole and can also be resistant to the usual dose of Fluconazole. These patients will respond to local 2% Miconazole cream. The other common treatment for Candida glabrata is Boric Acid Pessaries 600 mg nightly for 2 weeks.