Although vaginitis is a common problem, its diagnosis and treatment are sometimes problematic. Carr and colleagues review the most common causes of vaginitis (yeast infection, bacterial vaginosis and Trichomonas vaginalis infection) and suggest an evaluation of vaginal discharge and treatment options.

An abnormal vaginal discharge is one that adheres to the vaginal walls, causing irritation, pruritis or urinary symptoms, and ranging from white to yellow, gray or green in color. Besides infectious causes of vaginitis, noninfectious etiologies of vaginal discharge include chemical vaginitis and atrophic vaginitis.

Approximately 80 percent of yeast infections are due to Candida albicans. Women who are pregnant or taking oral contraceptives, broad-spectrum antibiotics or steroids, and those who are obese, immunocompromised or have diabetes have an increased susceptibility to yeast vaginitis. A stress-induced yeast vaginitis has also been described, although the pathophysiology of this condition is poorly understood. Yeast vaginitis often presents with severe irritation or pruritis of both the vagina and the vulva. Urinary tract symptoms are not uncommon. Examination reveals erythema, inflammation and an adherent discharge described as “cottage cheese–like.” The diagnosis is made when hyphae are seen on a potassium hydroxide wet mount. Other characteristics of candidal vaginitis include a pH of less than 4.5 and a lack of odor to the discharge. Infrequent infection can be successfully treated with an over-the-counter preparation of miconazole or clotrimazole for seven days. Vaginal and vulvar involvement may necessitate use of both vaginal suppositories and creams. Women with recurring yeast vaginitis should be treated with a prescription anti-fungal medication. Some single-dose treatments are available, but they may cause adverse effects (e.g., nausea, vomiting and diarrhea) or may not be as efficacious as longer courses of treatment. In women with frequent vaginal yeast infections, consideration should be given to discontinuing oral contraceptives as well as testing for human immunodeficiency virus infection.

Bacterial vaginosis, formerly known as non-specific vaginitis, has a poorly understood pathophysiology and may be asymptomatic in up to 50 percent of women with the disorder. It is associated with abnormal Papanicolaou smears (usually atypical squamous cells of undetermined significance), pelvic inflammatory disease (although this is controversial) and upper genital tract infection. The risk of premature rupture of the membranes and preterm delivery has also been reported in patients with bacterial vaginosis, although it has been shown that this risk can be reduced with oral metronidazole treatment.

Women with bacterial vaginosis do not have a standard clinical presentation. Typically, three of the following four criteria must be present to meet the diagnosis of bacterial vaginosis: a pH of at least 4.5, a positive “whiff” test, a thin homogeneous discharge and the presence of clue cells on microscopic examination of a normal saline wet mount. A vaginal smear should always be obtained, whereas a vaginal culture may not be necessary. Treatment generally consists of oral or topical metronidazole or clindamycin. Treatment of asymptomatic patients is not necessary unless the patient is pregnant or scheduled for a vaginal surgical procedure.

Trichomonas vaginalis infection is more likely to occur in women of lower socioeconomic status and women with multiple sexual partners. The “strawberry cervix,” caused by intraepithelial hemorrhages, is present in only about 5 to 10 percent of patients with trichomonal infection. Trichomonas infection may be associated with abnormal Pap smears and pelvic inflammatory disease, as well as premature rupture of the membranes and neonatal respiratory tract infections. Trichomonas infection is characterized by a foul-smelling, profuse, watery green discharge. Inflammation of the vaginal mucosa is generally only mild. The pH is usually 6 to 7, and often many leukocytes are present. A normal saline wet mount is the best way to see the organism, a protozoan with four flagella. Options for treatment of trichomonal infection include metronidazole, with higher dosages in women with more resistant infections. Pregnant women with Trichomonas infection should take 2 g of metronidazole in a single dose and their sexual partners should also be treated.