Approach to vaginal discharge: Clinical sciences

Vaginal discharge is one of the most common reasons for patients to present for gynecologic care. Normal physiologic discharge is generally asymptomatic, but abnormal vaginal discharge can cause significant discomfort and pain, can adversely affect daily activities, and has a considerable impact on sexual functioning and self-image. Normal vaginal discharge is the result of a combination of endocervical and vaginal secretions, sloughing of vaginal epithelial cells, and the presence of normal vaginal flora.

A disruption of these components results in abnormal vaginal discharge, which is associated with vaginal or vulvar irritation, pain, or pruritus. Common causes of abnormal vaginal discharge include a foreign body in the vagina; vaginal inflammation; and vaginal or cervical infection.

Your first step in evaluating a patient who presents with vaginal discharge is a focused history and physical examination. Let's start with an assessment for a foreign body. During history taking, the patient may describe an increase in vaginal discharge and possibly recent sexual activity or tampon use. Patients may express concerns about a retained foreign body such as a tampon or condom. However, they may be unaware of the presence of a foreign object or unwilling to disclose the information.

Physical examination will reveal an abnormal, often purulent or even bloody, vaginal discharge and, if a foreign body is present on speculum examination, you have made your diagnosis.

Here’s a clinical pearl. Malodorous purulent vaginal discharge is often caused by retained hygiene products such as tampons, and in prepubertal female patients, fragments of toilet paper are a common culprit. However, if the foreign body is an item that is unusual or unexpected, make sure to consider and screen for sexual abuse.

If there is no evidence of a foreign body, the next step is to assess for the presence of vaginal inflammation or infection, known as vaginitis, starting with these first three. Let’s discuss the first possible scenario, physiologic discharge, where you’d actually be ruling out vaginitis. Patients will report a history of increased vaginal discharge without odor, as well as an absence of vaginal or vulvar irritation. The physical exam will reveal a white or clear vaginal discharge.

In this case, consider physiologic discharge, and obtain samples of the discharge from the vaginal walls and fornices. Examine the discharge with saline microscopy and test the vaginal pH. If the saline microscopy reveals mature squamous cells and abundant lactobacilli, and the pH is 3.5 to 4.5, those are all normal findings, so you can rule out vaginitis and diagnose physiologic discharge.

Here’s a clinical pearl to keep in mind! Physiologic leukorrhea is a normal condition that typically precedes the onset of menses by 3 to 6 months, and is associated with an otherwise asymptomatic and odorless clear to white vaginal discharge. A microscopic exam of a swab specimen will reveal an abundance of epithelial cells, which further supports the diagnosis.

And another clinical pear! Poor hygiene and long baths can cause vaginal discharge and irritation, particularly in young patients. Counsel regarding good hygiene practices, including wiping from front to back and wearing cotton underwear; as well as avoiding scented hygiene products and bubble baths.

Now let’s discuss bacterial vaginosis, which is the most common cause of abnormal vaginal discharge. Keep in mind this is not a true infection but a dysbiosis, meaning it’s an imbalance of the normal microorganisms in the vagina. This happens when the normal hydrogen peroxide and lactic acid producing Lactobacillus species are replaced by an overgrowth of anaerobes.

If the patient reports a thin watery discharge with an unpleasant odor, and the physical exam is positive for a thin gray-white vaginal discharge with an amine or “fishy” odor, consider bacterial vaginosis. Assess for bacterial vaginosis by sampling the vaginal discharge. Perform saline microscopy, looking for clue cells and lactobacilli. Test the vaginal pH and perform a KOH whiff test.

Next, assess for the Amsel criteria, which include thin gray-white vaginal discharge on physical exam; microscopy revealing more than 20% clue cells; vaginal fluid pH greater than 4.5; and a positive KOH whiff test. If 3 out of the 4 criteria are met, you can diagnose bacterial vaginosis.

Our next possible source of vaginitis is vulvovaginal candidiasis, which is the second most common form of vaginitis, after bacterial vaginosis. It is the result of inflammation of the vagina and vulva due to infection with yeast, most commonly by Candida albicans.

Patients typically report thick, white vaginal discharge and vaginal itching. They may also report associated symptoms of vulvar itching, pain, redness, or swelling. The physical exam will reveal a thick, white, curd-like vaginal discharge. The vulva may appear erythematous, edematous, and there may be excoriations from scratching that may develop fissures. With these findings, consider vulvovaginal candidiasis.

Sample the vaginal discharge, perform microscopy with 10% KOH, and test the vaginal pH. It is also possible to send the vaginal discharge for a culture or PCR testing for Candida species.