Also Known As
Bacterial Vaginosis
Vaginal Infection
Yeast Infection
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This article waslast modified on January 5, 2018.
What are vaginitis and vaginosis?

Vaginosis is an infection of the vagina. Vaginitis is an inflammation of the vagina that may be due to vaginosis or other factors such as an allergy, irritant, or a decrease in the female hormone estrogen. Vaginitis is a very common condition, most frequently affecting women of child-bearing age. It has been reported by the Centers for Disease Control and Prevention (CDC) to affect over 21 million women between the ages of 14 to 49 years. The condition can cause genital itching and burning and sometimes an abnormal vaginal discharge. When the external genitalia (vulva) are also inflamed, the condition may be referred to as vulvovaginitis. The most common terms used by the general public for vaginitis/vaginosis are "yeast infection" and "vaginal infection."

The vagina normally maintains a dynamic balance of normal flora – a mixture of "good" microorganisms that help protect the vagina, maintain its moderately acidic environment, and discourage the growth of disease-causing microorganisms. Lactobacilli are the most frequently encountered normal flora bacteria. A mixture of other microorganisms, such as corynebacteria, and some yeast may also be found.

A small amount of daily vaginal discharge is normal. This is usually clear or milky and varies in consistency and quantity during a woman's menstrual cycle.

Accordion Title
About Vaginitis and Vaginosis
  • Causes

    Anything that disrupts the balance of normal flora and/or that irritates the tissues of the vagina or vulva can potentially cause vaginitis.

    The most frequent causes of vaginitis/vaginosis (up to 90%) are infections due to:

    • Bacterial vaginosis, caused by a complex change in vaginal flora with a decrease in the number of normal lactobacilli and an increase in other bacteria, including Gardnerella vaginalis and Mycoplasma hominis.
    • Candida albicans (yeast) infection, also called candidiasis, and sometimes caused by other Candida species
    • Trichomonas vaginalis infection, also called trichomoniasis or "Trich," is a sexually transmitted parasitic infection.

    Some other causes of vaginitis include:

    • Allergic and irritant reactions to feminine hygiene products, use of petroleum jelly products intravaginally, bubble baths, tight underclothing, synthetic fabrics that hold in moisture, perfumes, deodorant soaps, use of fabric softener sheets, latex condoms, etc.
    • Thinning of the skin in the vagina and a loss of lubrication that is due to decreased estrogen; this is called atrophic vaginitis and is primarily seen in women during and after menopause.
    • Hormonal imbalances
    • Rarely, a foreign body in the vagina (such as a small piece of toilet tissue in a child or a forgotten tampon in a menstruating woman); this can irritate and cause an infection.

    Bacterial vaginosis can make a woman more vulnerable to other infections, specifically sexually transmitted diseases (STDs). STDs other than a trichomonas infection that can sometimes cause vaginitis/vaginosis include:

    Vaginitis and vaginosis may occur at any age but are most common in women of child-bearing age who are sexually active, though it is important to note that many causes can also occur in those who are celibate and/or have never had sex. A woman may have more than one cause of vaginitis/vaginosis at a time.

    Risk factors for vaginitis/vaginosis include:

    • Antibiotic use (can cause a loss of "good" bacteria)
    • Pregnancy (causes hormonal changes that may lead to irritation of the vagina)
    • Frequent douching (can cause irritation and/or loss of normal flora)
    • Multiple sex partners and/or a new sex partner
    • Intrauterine device (IUD) use
    • Oral contraceptives
    • Underlying diseases, such as poorly controlled diabetes, skin diseases (dermatitis), and other conditions that affect the immune system
    • Poor hygiene, especially when using the toilet
    • Smoking
  • Signs and Symptoms

    The signs and symptoms associated with vaginitis/vaginosis may be vague and non-specific, involving general itching, pain, burning, redness, and swelling of the vagina. Depending on the cause, some distinctive signs and symptoms may be present and include one or more of the following:

    • Bacterial infection (vaginosis)—a vaginal discharge that is thin, grey, or milky with an unpleasant fishy smell (due to chemicals called amines that increase the pH in the vagina) that is especially noticeable after sexual intercourse. The affected person may or may not have itching and irritation. A significant number of women may have bacterial vaginosis without having noticeable symptoms.
    • Yeast infection (candidiasis)—a vaginal discharge that can be thick and white like cottage cheese, along with itching, burning, burning with urination, redness and swelling, and painful sexual intercourse.
    • Trichomoniasis—a yellowish-greenish vaginal discharge that may be "frothy" and is unpleasant smelling, itching, redness, painful sexual intercourse, and painful urination. Small red sores may be visible on the walls of the vagina or cervix during a pelvic exam. However, many women with trichomoniasis have no noticeable symptoms.
    • Atrophic vaginitis—this condition, occurring in some women entering or in menopause, is defined as a thinning of the walls of the vagina. The women affected may have vaginal dryness, itching, and/or burning, pain during sexual intercourse, and a small amount of bleeding after sexual intercourse.

    Rarely, the causes of vaginitis/vaginosis may lead to complications such as inflammation of the cervix or lining of the uterus or pelvic inflammatory disease (PID). In a woman who is pregnant, vaginosis can sometimes cause premature labor and, in some cases, can lead to the transmission of an infection from a mother to her newborn. Women who have a vitamin D deficiency and are pregnant may be more susceptible to bacterial vaginosis. Bacterial vaginosis has also been associated with miscarriages in the second trimester of pregnancy.

  • Tests

    The diagnostic process begins with a physical exam, including a pelvic exam, and a medical history. The doctor will want to know about a woman's symptoms, symptom duration and frequency, prescribed medications (such as antibiotics or oral contraceptives), and any over-the-counter treatments the woman may have tried. The doctor may ask the woman about personal habits (douching, use of feminine products or scented soaps, tight clothing, etc.) and about sexual practices. From this information, a decision may be made about what type of testing should be performed.

    The goals with testing are to diagnose vaginitis/vaginosis and to determine the underlying cause in order to help guide treatment. Testing is also used to evaluate the best treatment options in those who do not respond to initial therapy and/or who have recurrent episodes.

    Clinical diagnosis of bacterial vaginosis is based on the Amsel criteria, where three of the four following symptoms are present:

    • Grayish-white vaginal discharge
    • Vaginal pH greater than 4.5
    • Presence of "clue" cells as determined by a wet prep (see below)
    • Fishy odor present with the addition of 10% potassium hydroxide (whiff test below)

    Laboratory tests

    A few testing methods may be performed in a doctor's office or medical clinic by the health care practitioner, or a sample may be collected and sent to a laboratory.

    The "gold standard" for the diagnosis of bacterial vaginosis is the direct examination of the vaginal secretions, which can be viewed microscopically as an unstained wet mount or as a Gram stained slide.

    Wet Prep (Wet Mount/Smear)
    A drop of vaginal discharge is placed on a glass slide and then examined under the microscope. Examples of typical findings include:

    • Bacterial vaginosis—the presence of "clue cells," which are vaginal epithelial cells with most of the surface covered by bacteria, and the presence of few to no white blood cells (WBCs) are characteristic.
    • Candidiasis—yeast may be seen as budding yeast and/or tube or branch-like structures (pseudohyphae).
    • Trichomoniasis—these are parasites that can be seen as oval bodies with hair-like structures (flagella) that move. An increased number of WBCs may also be seen.

    Gram Stain
    Vaginal fluid is placed on a glass slide and specially stained (Gram stain). The specimen is observed under a microscope for certain bacterial cell types (morphotypes) and the evaluation is based on the abundance of each type of bacteria. If 20% or more of the epithelial cells are covered by bacteria ("clue cells"), this is diagnostic for bacterial vaginitis. A decrease in the number of normal bacterial cells such as Lactobacillus species is associated with bacterial vaginosis. The presence of yeast cells can also be detected with a Gram stain, while the parasite Trichomonas is not detected by this method.

    Other critical tests on the sample include the following:

    pH Test
    Vaginal discharge is checked for pH.

    • A pH of less than 4.5 is normal but can also be seen with a yeast infection (candidiasis).
    • An increased pH (such as greater than 5.0) may be seen with bacterial vaginosis and with trichomoniasis.

    Whiff (or Sniff) Test and KOH Prep
    A sample of the vaginal discharge is placed on a glass slide with a drop of 10% potassium hydroxide (KOH).

    • Bacterial vaginosis: chemical compounds called amines will be released, causing a fishy odor.
    • Candidiasis: budding yeast and pseudohyphae can often be seen more easily.
    • Trichomoniasis: can also release an unpleasant odor.

    Vaginal Cultures

    • Bacterial vaginal cultures should be discouraged for the diagnosis of bacterial vaginitis. Gardnerella vaginalis can be cultured from 50-60% of healthy, asymptomatic women and therefore the growth of these bacteria in culture is difficult to interpret.
    • Candidiasis: a fungal culture may be ordered to help guide treatment with persistent or recurrent infections and can be used to identify which yeast is present.
    • Trichomoniasis:  a special trichomonas culture may be performed to detect trichomonads when microscopic exam is not sufficient.

    Additional test methods are available for identifying the causes of vaginitis/vaginosis, such as:

    • Molecular methods (e.g., nucleic acid amplification, NAAT) for identifying trichomonas, yeast or bacterial vaginosis.
    • Rapid point-of-care tests for detecting trichomonas or bacterial vaginosis

    Other Tests
    If someone has trichomoniasis and/or STDs are suspected, additional testing may be performed, including use of highly specific polymerase chain reaction (PCR) testing to check for other STDs, such as:

    If a person has recurrent yeast infections, follow-up testing may be performed to look for underlying conditions that may be contributing to the vaginitis/vaginosis, such as diabetes.

    Non-Laboratory Tests
    Other than a physical examination, other non-laboratory tests, such as imaging, are usually not required for diagnosing vaginitis/vaginosis. However, if a serious complication such as pelvic inflammatory disease (PID) is suspected, then a pelvic or transvaginal ultrasound may be performed. This test may reveal the presence of enlarged fallopian tubes or an abscess.

  • Treatment

    It is not always possible to prevent vaginosis or vaginitis, but women can take steps to reduce the likelihood and reduce recurrence. These may include:

    • Avoid douching and/or frequent baths.
    • Avoid feminine hygiene products, perfumed soaps, and other potential chemical irritants.
    • Avoid tight clothing and synthetic underclothes that may trap moisture.
    • Practice safe sex.
    • Practice (and teach children) good hygiene.

    There are several standard topical intravaginal treatments (creams or suppositories placed inside the vagina) available for bacterial vaginosis and candidiasis, as well as oral treatments for bacterial vaginosis, candidiasis, and trichomoniasis. There are several different timing and dosing options available. Women should always follow the instructions provided.

    For trichomoniasis and other sexually transmitted infections, treatment of a person's sex partner is often recommended to increase the cure rate and help prevent re-infection in the woman. Trichomoniasis is usually self-limited in men, resolving within a couple of weeks.

    If an uncomplicated yeast infection occurs again and the woman recognizes the symptoms, then over-the-counter treatment may be sufficient. However, if a woman's symptoms recur or persist, she should consult with her health care provider.

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