Accurate and efficient laboratory confirmation of vulvovaginal candidiasis is problematic. Potassium hydroxide (KOH) preparations of vaginal secretions may fail to identify candidiasis in as many as one half of patients with cultures positive for Candida albicans. In addition, wet mount preparations may not distinguish between the organism as a vaginal commensal and as a pathogen for vulvovaginal infection. Eckert and colleagues assessed risk factors and clinical manifestations of vulvovaginal candidiasis to identify a better way to establish the diagnosis of vulvovaginal candidiasis.
The study included 774 women 16 to 50 years of age who presented to a sexually transmitted disease clinic with symptoms of infection. Patients who were pregnant, had received oral antibiotics or vaginal medications in the previous 14 days, had undergone hysterectomy, had a severe mental or physical handicap or could not speak English well were excluded from the study.
In addition to demographic characteristics, other data obtained included the patient's medical, reproductive and contraceptive history, current symptoms, findings on physical and pelvic examination, and the results of vaginal pH determination, KOH and saline preparations of vaginal secretions, and culture of vaginal specimens for Candida. The authors used the term “wet mount” to describe a combination of saline and KOH preparations. Vaginal specimens were first examined in saline for clue cells, trichomonads and white blood cells. KOH was then added to the preparation for microscopic detection of hyphae. Vaginal specimens were also collected for culture of C. albicans.
The organism was identified in 186 of the 774 women (24.0 percent). Of those with positive cultures, 104 (55.9 percent) also had wet mount examinations positive for C. albicans. An additional 15 patients were found to have cultures positive for other Candida species; all of the latter women had negative wet mount results.
Statistical analysis of the data demonstrated that women with positive cultures were significantly more likely to present with the chief complaint of vulvar itching or burning and, when asked, to report symptoms of vulvar dysuria and pruritus. Although signs of vulvar edema, fissures, excoriations and vaginal erythema, or a thick, curdy discharge were infrequent, these signs, when present, correlated strongly with positive cultures. Patients with positive cultures were more likely to be nulligravid, to report using condoms as their method of birth control, to have sexual intercourse more than four times per month, to present in the second half of their menstrual cycle and to report antibiotic use in the previous 15 to 30 days. Current bacterial vaginosis, gonorrhea, chlamydial infection and vaginal trichomoniasis were associated negatively with a positive C. albicans culture.
On the basis of the statistical analysis, the authors devised a clinical algorithm that would allow reliable and cost-effective investigation of symptomatic vulvovaginal candidiasis. They recommend that wet mount preparation of vaginal secretions be obtained in all women with symptoms or signs of vulvovaginal candidiasis. Treatment of candidiasis should be initiated if the wet mount preparations are positive. If the results are negative despite a clinical presentation that suggests vulvovaginal candidiasis, culture for C. albicans should be obtained, and treatment should be initiated in patients with positive cultures. The authors note that implementation of such a management strategy would result in treatment of 90 percent of women who meet the definition of vulvovaginal candidiasis while it would limit the expense of potentially unnecessary cultures. The authors note that vaginal discharge is a particularly poor indicator of the need for over-the-counter therapy for vulvovaginal candidiasis.