The evaluation of
vaginitis requires visual inspection of the vaginal discharge, the vagina, and
the cervix, as well as the collection and evaluation of a discharge specimen
under the microscope.
The following characteristics of the vaginal discharge should be noted during examination:
- Color
- Viscosity
- Adherence to vaginal walls, and
- Presence of an odor.
Visualization of the cervix is important in order to rule out cervicitis as a source of abnormal
vaginal discharge.
A discharge specimen should be collected from the lateral wall of the vagina. A specimen slide,
called a wet mount, can be made with a drop of warm
0.85% saline and a drop of the discharge specimen. An alternative
method of wet mount preparation is to place the discharge swab into a test tube with
<1ml of saline and place a drop onto a specimen slide. With a cover slip
overlaid, the slide should be examined immediately under a microscope at both low and high power.
The use of the following diagnostic criteria can be helpful in the differential diagnosis of vaginitis:
- Determination of the vaginal pH
- Assessment of a fishy odor, called the "whiff" test, from the discharge after placing a drop of 10% KOH on the slide
- Examination of the wet mount under the microscope after adding a drop of 10% KOH to the slide; and
- Examination under the microscope of the
0.85% saline wet mount.
The following chart, vaginitis differentiation, is useful in the differential diagnosis of vaginitis. Given the differences in microscopic appearance of vaginal specimens, pH, and visual characteristics of discharge, the three common causes of vaginitis (Trichomonas vaginalis, Candiada albicans, and bacterial vaginosis) can be distinguished. In symptomatic patients in whom these have been excluded, one must consider hypersensitivity, irritant and allergic vulvovaginitis, or physiologic leukorrhea as a cause of symptoms.
