Statistics from Altmetric.com
Resistance of Candida albicans to triazoles is uncommon with short term treatment but has been increasingly reported in immunocompromised patients, including those with HIV infection who are receiving long term systemic or maintenance therapy. Vaginal triazole resistant C albicans isolates are extremely rare in non-immunocompromised HIV seronegative women.1 To our knowledge, only a single case has been reported to date.2 As over the counter oral triazole antifungals are now widely available there is potential for drug resistance to increase. We report another case of vulvovaginitis due to triazole resistant C albicans in an otherwise healthy woman.
The patient was a 28 year old woman who presented with symptoms of vulval pruritis and profuse vaginal discharge for six months. She was not taking regular medication but had used clotrimazole and fluconazole several times in the preceding months with no clinical improvement. On examination, the vulva looked healthy but the vagina was erythematous and white plaques were noted. The cervix appeared normal and bimanual pelvic examination was unremarkable. The patient declined HIV serology but was fit and well with no stigmata of HIV infection and no risk factors.
Microscopic examination of vaginal secretions did not reveal any yeast blastospores or pseudohyphae, nor any clue cells or trichomonads. However, C albicans was isolated on culture. In view of the documented history of a lack of response to topical and oral azoles, the patient was treated with nystatin pessaries daily for two weeks, while antifungal sensitivity tests were being performed. The patient returned to clinic two weeks later and reported only slight improvement in her symptoms despite using vaginal nystatin as prescribed. Unfortunately, the sensitivity test results were not available at this time and the patient subsequently failed to attend the clinic.
In vitro sensitivity testing by the Mycology Reference Laboratories (Bristol, UK) using the NCCLS M27A assay3 revealed that the vaginal C albicans isolate was resistant to both fluconazole (minimum inhibitory concentration (MIC) > 64 μg/ml) and itraconazole (MIC > 16 μg/ml) but sensitive to nystatin (MIC = 2 μg/ml), miconazole (MIC < 0.125 mg/l) and clotrimazole (MIC = 0.25 mg/l).
In vitro susceptibility to antifungal agents appears to be a poor predictor of therapeutic success but in vitro resistance, defined by high MIC levels, correlates well with clinical resistance.4,5 However, despite the lack of a clear correlation between in vitro susceptibility and clinical response such data may assist the selection of alternative antifungal agents in cases of apparent clinical resistance.
As the patient did not attend for review, we do not know whether a microbiological cure was effected by this therapy, and therefore, we cannot exclude the possibility that the patient’s symptoms were due to other pathology. Nevertheless, this case indicates that the possibility of triazole resistant C albicans should be considered in non-immunocompromised individuals with refractory vulvovaginal symptoms and a history of self medication.
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.