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Vaginal Wet Mount
A vaginal wet mount (sometimes called a vaginal smear) is a test to find the cause of vaginitis, or inflammation of the vagina and the area around the vagina (vulva).
Vaginitis is often caused by an infection. But it may also be caused by a reaction to vaginal products such as soap, bath oils, spermicidal jelly, or douches. It may cause symptoms such as vaginal itching, pain, or discharge.
Infections that can cause vaginitis are common and include:
- Yeast infection. Most vaginal yeast infections are caused by a type of yeast called Candida albicans. A yeast infection is also called a candida infection, or candidiasis. A vaginal yeast infection often causes itching and a white, lumpy discharge that looks like cottage cheese. It also causes pain with sexual intercourse. A yeast infection is not a sexually transmitted infection (STI).
- Trichomoniasis. This is an infection caused by a parasite (Trichomonas vaginalis). It is sometimes called trichomonas infection, trichomonal infection, or simply trich (say "trick"). Trichomoniasis may cause a vaginal discharge that is yellow-green, foamy, and bad-smelling. Pain with sex or urination may be present. Lower belly pain may also be present. Trichomoniasis is spread by sexual contact and is an STI.
- Bacterial vaginosis. This is a change in the balance of bacteria that are normally present in the vagina. The vaginal discharge is often thin and milky with a strong fishy odor. Many women have no symptoms. Bacterial vaginosis is not an STI.
- Other sexually transmitted infections (STIs). Infections such as chlamydia, genital warts, syphilis, herpes simplex, and gonorrhea can also affect the vagina. These infections are found by doing other tests.
A vaginal sample may be tested by:
- Wet mount. A sample of the vaginal discharge is placed on a glass slide and mixed with a salt solution. The slide is looked at under a microscope for bacteria, yeast cells, trichomoniasis (trichomonads), white blood cells that show an infection, or clue cells that show bacterial vaginosis.
- KOH slide. A sample of the vaginal discharge is placed on a slide and mixed with a solution of potassium hydroxide (KOH). The KOH makes it easier to see yeast cells.
- Vaginal pH. The normal vaginal pH is 3.8 to 4.5. Bacterial vaginosis, trichomoniasis, and atrophic vaginitis often cause a vaginal pH higher than 4.5.
- Whiff test. Several drops of a potassium hydroxide (KOH) solution are added to a sample of the vaginal discharge. A strong fishy odor from the mix means bacterial vaginosis is present.
Why It Is Done
A vaginal wet mount is done to find the cause of vaginal itching, burning, rash, odor, or discharge.
How To Prepare
Do not douche, use tampons, or use vaginal medicines for 24 hours before the test.
A vaginal wet mount is not usually done during your menstrual period. Menstrual blood on the slide can change the results.
If you are or might be pregnant, tell your doctor before the vaginal wet mount is done.
How It Is Done
You will take off your clothes below the waist and drape a gown around your waist. You will then lie on your back on an examination table with your feet raised and supported by stirrups. This allows your doctor to look at the genital area.
Your doctor will put a smooth, curved speculum into your vagina. The speculum gently spreads apart the vaginal walls, which allows your doctor to see the inside of the vagina and the cervix.
Samples of fluid inside the vagina are taken with a swab or spatula. The sample is put on a slide for testing.
How It Feels
You may feel some discomfort when the speculum is inserted, especially if your vagina is irritated and tender. There may be a small amount of bleeding after this test.
There are no problems from collecting a sample of vaginal secretions.
Your doctor may talk to you about the results after the test. If the sample needs to be looked at by a lab, the results may be ready in 1 to 2 days.
No abnormal vaginal discharge is present. Every woman has vaginal discharge that is normal for her.
A white, lumpy discharge that looks like cottage cheese may mean a vaginal yeast infection is present. A yellow-green, foamy discharge that has a bad odor may mean trichomoniasis is present. A thin, gray-white vaginal discharge with a strong fishy odor may mean bacterial vaginosis is present.
No yeast, bacteria, trichomoniasis, or clue cells are found on the slide. White blood cells are not present or very low in number.
High numbers of white blood cells often mean a vaginal infection. Yeast cells found on the wet mount mean a vaginal yeast infection is present. Trichomonads on the wet mount mean trichomoniasis is present. Clue cells may mean bacterial vaginosis is present.
No yeast is found.
The amount or type of yeast cells may mean a yeast infection is present. Yeast is normally found in the vagina.
Vaginal pH is about 3.8–4.5.
Vaginal pH is higher than 4.5.
Adding potassium hydroxide (KOH) solution to vaginal discharge does not cause a fishy odor.
A fishy odor made by the whiff test means bacterial vaginosis is present.
Current as of: February 11, 2021
Author: Healthwise Staff
Sarah Marshall MD - Family Medicine
E. Gregory Thompson MD - Internal Medicine
Martin J. Gabica MD - Family Medicine
Kathleen Romito MD - Family Medicine
Deborah A. Penava BA, MD, FRCSC, MPH - Obstetrics and Gynecology
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