Vulvovaginitis prompts more than 10 million physician visits annually in the United States. Most cases are caused by infectious agents, including Gardnerella vaginalis, Trichomonas vaginalis, and Candida species.
Diagnosis of a specific causative organism in patients with vulvovaginitis can be difficult. Although signs, symptoms, and laboratory testing may suggest an organism, significant overlap exists in the specificity and sensitivity of these diagnostic tools, and empiric treatment may be the best approach.
Bacterial vaginosis is caused by Gardnerella vaginalis, an anaerobic bacillus. Infection occurs when this organism replaces the usual Lactobacillus species found in vaginal flora. Although infection is associated with multiple sexual partners, women who are not sexually active may acquire this infection; as such, it should not be considered a sexually transmitted disease. This organism is found in up to 40% of asymptomatic women, and men may harbor the organism asymptomatically in the urethra, posing a potential infectious source.
Symptomatic patients present complaining of a foul or fishy vaginal odor and may have a vaginal discharge (Table 19.1). Only a minority of patients with this infection complain of pruritis. On examination, the vaginal mucosa is not usually inflamed, but there is frequently a thin, homogeneous, gray-white vaginal discharge that may be fishy or foul smelling.
A vaginal swab should be obtained for Gram stain and/or wet preparation. To increase diagnostic accuracy, vaginal fluid should be pH tested.