Practical Guide to Diagnosing and Treating Vaginitis

Bacterial vaginosis (BV), candidiasis, and trichomoniasis account for more than 90% of vaginal infections. BV typically is associated with a decrease in commensal, protective lactobacilli and a proliferation of other flora. Mobiluncus is pathognomonic but found in only 20% of cases. Presence of 3 of 4 criteria indicates BV: a homogenous noninflammatory discharge (not many WBCs); pH >4.5; clue cells (bacteria attached to borders of epithelial cells, > 20 % of epithelial cells); and a positive whiff test. New intravaginal BV preparations cause less-adverse systemic effects than oral regimens. Trichomonas vaginalis, a protozoan, appears to be sexually transmitted and causes up to 25% of vaginitis cases. Diagnosis is made by observation of a foul, frothy discharge; pH >4.5 (present in 70% of cases); punctate cervical microhemorrhages (25% of cases); and motile trichomonads on wet mount (50%-75% of cases). Recommended treatment is a single 2g dose of oral metronidazole. Treatment failure is usually due to nontreatment of the male partner. Candidiasis typically presents as a thick, "curdled" white discharge or vulvar pruritus, with a hyperemic vagina and an erythematous and/or excoriated vulva. Vaginal pH is usually in the normal range of 3.8-4.2 in uncomplicated candidiasis. Microscopic examination of the discharge reveals hyphae or budding yeast in 50%-70% of cases. While the most common offender is Candida albicans, Candida tropicalis and Candida glabrata have become increasingly prevalent. Approximately 15% of C albicans organisms are resistant to clotrimazole and miconazole. Recurrent infections may be treated with fluconazole 150mg weekly for up to 12 consecutive weeks.