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Chapter 6: Vaginitis

Vaginitis accounts for one of the most common reasons women visit a health care provider. Currently, three major types of vaginitis are recognized: vaginal trichomoniasis, vulvovaginal candidiasis (VVC) and bacterial vaginosis (BV).


Vaginal trichomoniasis is caused by the protozoan Trichomonas vaginalis, and VVC is caused by Candida spp., usually C. albicans. Several risk factors predispose women to VVC and include pregnancy, oral contraceptive use, menstruation, antibiotic use, corticosteroid use, diabetes mellitus, and immunosuppression, including HIV infection.

BV is the most common cause of vaginitis. Though sexually associated, whether BV is sexually transmitted, remains unknown. It is characterized by a profound loss of hydrogen peroxide producing Lactobacilli and an overgrowth of “commensal” anaerobes, including Gardnerella vaginalis, Megasphaera, Atopobium and a number of BV associated bacteria (BVAB1, BVAB2, BVAB3).  Some populations of women appear to be at increased risk of BV and include:

  • Black women
  • Smokers
  • Women who douche
  • Women with new or multiple male sexual partners
  • Women with uncircumcised male sexual partners
  • Women who have sex with women

Screening for trichomoniasis should be considered in all sexually active women who present with an abnormal vaginal discharge and among those at high risk for infection (i.e., women who have new or multiple partners, have a history of STD, exchange sex for payment, and use injection drugs). Men may be infected with T. vaginalis and have no symptoms.    


Effective treatment of vaginitis relies on a comprehensive evaluation. Because clinical symptoms are often non-specific, a physical examination is paramount to an accurate diagnosis. Patients with vaginitis generally complain of increased or abnormal vaginal discharge, abnormal odor, vulvar itching, dysuria and, often, dyspareunia.

Clinical Examination and Laboratory

Evaluation of patients with suspected vaginitis includes evaluation for common STD, determination of vaginal pH and microscopy, if available. (See Figure 1.) The amount, consistency, and location of the discharge within the vagina should be noted. In the absence of examination, some point-of-care tests can detect the most common pathogens associated with vaginitis, but the opportunity to assess the cervix as a source of discharge is lost; this may be critical in women at risk for cervical infection with gonorrhea or chlamydia.

  1. Examine the external and internal labia for any signs, including fissures, edema, or erythema (all consistent with VVC).
  2. Remove a sample of the discharge from the lateral vaginal wall with a swab, avoiding contamination with cervical mucous.
    1. Note its color in comparison with the white background of the swab.
    2. Determine pH directly by rolling the swab onto pH indicator paper. (The pH of normal vaginal fluid is in the range of 4.0-4.5.)
  3. Take an additional specimen with another swab and mix separately into a drop of saline and a drop of 10% KOH on a microscope slide. Place a separate coverslip on the saline and KOH wet preps for microscopic examination. Watch the video demonstration of the microscopic examination of a vaginal wet prep:

    Once a vaginal sample is available, providers can diagnose BV using Amsel criteria: three of the following must be present:
    1. homogeneous discharge
    2. pH>4.5
    3. clue cells (>20%; see image 6)
    4. amine odor on addition of KOH (+whiff test)

Figure 6-1 Management of a female with vaginal discharge.

(Figure 6-1 reproduced with the permission of the Sylvie Ratelle STD/HIVPrevention Training Center of New England) 

Table 6-1: "Differential Diagnosis of Vaginitis" outlines the typical findings from the physical and microscopic examinations that characterize the three main types of vaginitis.

Table 6-1

Differential Diagnosis of Vaginitis
Patient Complaint None Thin discharge, odor, itch, 50% asymptomatic Itch, burning, dysuria, thick discharge Odor, itch, discharge, dysuria
Exam Findings Normal Thin discharge, fishy smell Vulvar/vaginal edema/erythema, fissures, excoriations, satellite papules Cervical petechiae ("strawberry cervix")
Vaginal Discharge Clear to white, colorless, odorless Increased, homogenous, thin, white to gray, adherent, fishy smell Thick, clumpy, white, "cottage cheese," increased Gray or yellow-green, frothy, adherent, increased
Vaginal pH ≤4.5 >4.5 Usually ≤4.5 Usually >4.5
KOH "whiff test" Negative Positive Negative Often positive
Saline Wet Mount Normal epithelial cells; numerous lactobacilli Clue cells (≥20%) no/few WBCs Normal epithelial cells, >1:1 ration of WBCs:epithelial cells, pseudohyphae or budding yeast Motile flagellated protozoa, >1:1 ration of WEC:epithelial cells
KOH Preparation Epithelial cell "ghosts" Epithelial cell "ghosts" Pseudohyphae or budding yeast Epithelial cell "ghosts"


The images below demonstrate the typical appearance of the vaginal discharge of VVC, vaginal trichomoniasis and BV.

Image 6-1. Candida discharge
Image 1.
Thick, white, curd-like discharge of candida
Image 6-2. Trichomonas discharge
Image 2.
Thin, watery, cervical discharge of trichomonas infection
Image 6-3. Bacterial vaginosis Image 3.
Adherent, grayish discharge of bacterial vaginosis
Image 41. Yeast Image 4.
Yeast seen in 10% KOH set prep
Image 6-5. Trichomonas vaginalis
Image 5.
T. vaginalis motile organisms seen in wet prep
Image 6-6. Vaginal saline prep with clue cells (above); normal (below)
Image 6.
Vaginal saline prep with clue cells (above); normal (below)

Unfortunately, diagnosis of vaginal trichomoniasis is still most commonly made by microscopy of vaginal secretions; this method detects only between 30%-50% of infections detected by nucleic acid amplification testing (NAAT). Culturing for the parasite is another common way to diagnose infection; though results may take 3-7 days. Other FDA-pending or cleared tests for trichomoniasis in women include OSOM Trichomonas Rapid Antigen Test (Genzyme Diagnostics, Cambridge, Massachusetts) and transcription-mediated amplification testing (TMA; APTIMA TV, Gen-Probe).  Some data supports a finding of three times as many cases of trichomoniasis using NAAT compared to standard wet preparation (Hollman, D., et al. 2010).  Moreover, pending validation, NAATs for T. vaginalis in men can be performed on semen as well as urethral swab, or urine.


Symptoms and signs of abnormal vaginal discharge,are often secondary to infection. Vaginal discharge may also represent a normal physiologic discharge. The most important initial step in evaluation of vaginal discharge is to exclude cervicitis (see Chapter 7). If neither cervicitis nor vaginitis appear to be present, the patient should be re-examined in several days rather than treated nonspecifically for an uncertain diagnosis. Targeted treatment is optimal and only warranted in patients with symptoms. The differential diagnosis for conditions that may mimic vaginitis or cervicitis include:

  • irritant vaginitis secondary to exogenous products, such as vaginal spermicide, douches, lubricants or other cosmetic products,
  • infections associated with other intravaginal foreign bodies
  • generalized mucosal inflammation, for example, Stevens-Johnson Syndrome
  • postmenopausal vaginal atrophy, and
  • vestibulitis due to inflammation.


For a more detailed discussion of these regimens and other treatment considerations, please refer to the 2010 CDC STD Treatment Guidelines at

Trichomonas vaginalis

Recommended Regimens

Metronidazole 2 g orally in a single dose


Tinidazole 2 g orally in a single dose

Alternative Regimen

Metronidazole 500 mg orally twice a day for 7 days*

NOTE: Patients should be advised to avoid consuming alcohol during treatment with metronidazole or tinidazole.  Abstinence from alcohol use should continue for 24 hours after completion of metronidazole or 72 hours after completion of tinidazole.

*Clinical trial data supports superiority of a multi-dose treatment regimen for T. vaginalis among HIV-infected women (Kissinger, P., et al. 2010).


Given high rate of reinfection among patients with trichomoniasis (17% reinfected within 3 months in one study), it may be reasonable to rescreen for T. vaginalis at 3 months after initial infection and treatment in sexually active women.

Treatment Failure

Low level resistance to metronidazole occurs in as many as 5% of cases of trichomoniasis (Schwebke, J.R. and F.J. Barrientes. 2006).  Most of these infections appear to respond to standard treatment regimens (single-dose oral metronidazole or tinidazole). If clinical failure occurs, higher doses and/or longer duration of tinidazole or metronidazole can be used.  Tinidazole has a longer serum half-life and reaches higher levels in genitourinary tissues than metronidazole. Swabs of vaginal fluid from women in whom treatment failure due to antibiotic resistance is suspected can be sent to CDC for sensitivity testing (; telephone: 404-718-4141).

  • If treatment failure occurs with the 2 g dose of metronidazole >> consider retreatment with metronidazole at 500 mg orally twice daily for 7 days. 
  • If failure occurs with metronidazole at 500 mg orally twice daily for 7 days >> consider re-treatment with tinidazole at 2 g or metronidazole at 2 g for 5 days.

Candida albicans

Recommended Regimens

Over-the-Counter Intravaginal agents*

Butoconazole 2% cream 5 g intravaginally for 3 days


 Clotrimazole 1% cream 5 g intravaginally for 7-14 days


Clotrimazole 2% cream 5 g intravaginally for 3 days


Miconazole 2% cream 5 g intravaginally for 7 days


Miconazole 4% cream 5 g intravaginally for 3 days


Miconazole 100 mg vaginal suppository, one suppository for 7 days


Miconazole 200 mg vaginal suppository, for 3 days


Miconazole 1,200 mg vaginal suppository, one suppository for 1 day


Tioconazole 6.5% ointment 5 g intravaginally in a single application

Prescription Intravaginal Agents:

Butoconazole 2% cream (single dose bioadhesive product), 5 g intravaginally for 1 day


Nystatin 100,000-unit vaginal tablet, one tablet for 14 days


Terconazole 0.4% cream 5 g intravaginally for 7 days


Terconazole 80 mg vaginal suppository, one suppository for 3 days

Oral Agent:

Fluconazole 150 mg oral tablet, one tablet in a single dose

*These creams and suppositories are oil-based and may weaken latex condoms and diaphragms. Refer to condom product labeling for further information.


In women with recurrent (>4 times a year) or severe episodes of vulvovaginal candidiasis, underlying risk factors (including diabetes mellitus or causes of immune deficiency, such as HIV) should be considered; however, the majority of such women have no such identifiable underlying cause.

Bacterial vaginosis (BV)

Treatment should be targeted to the symptomatic woman. No benefit has been demonstrated for treating asymptomatic women, including those that are pregnant.

Recommended Regimens

Metronidazole* 500 mg orally twice a day for 7 days


Metronidazole gel, 0.75%, one full applicator (5 g) intravaginally, once a day for 5 days


Clindamycin cream, 2%, one full applicator (5 g) intravaginally at bedtime for 7 days†

  *Patients should be advised to avoid consuming alcohol during treatment with metronidazole and for 24 hours thereafter.
† Clindamycin cream and ovules are oil-based and might weaken latex condoms and diaphragms (refer to clindamycin product labeling for additional information).

Alternative regimens

Tinidazole 2 g orally once daily for 2 days


Tinidazole 2 g orally once daily for 5 days


Clindamycin 300 mg orally twice daily for 7 days


Clindamycin ovules 100 mg intravaginally once at bedtime for 3 days


Despite the fact that BV is associated with numerous adverse consequences in pregnancy, including premature rupture of membranes, preterm labor, preterm birth, intra-amniotic infection, and postpartum endometritis, the only established benefits of therapy in this setting are to relieve vaginal symptoms and signs of infection.  Other potential benefits include reducing the possible risks associated with BV in pregnancy and reducing susceptibility to other STDs, including HIV.

Recommended Regimens for pregnant women

Metronidazole 500 mg orally twice a day for 7 days

Metronidazole 250 mg orally three times a day for 7 days

Clindamycin 300 mg orally twice a day for 7 days

Follow up

Clinical follow-up is unnecessary if symptoms resolve. There is some evidence supporting antimicrobial resistance in some BV-associated organisms, prompting concern for treatment failure. Optimal treatment for recurrent BV is unknown. Options after an initial course of routine therapy as above include suppressive therapy with metronidazole gel (0.75%) twice per week for 4-6 months, though treatment benefit may lapse once suppressive therapy is discontinued (Sobel, J.D., et al. 2006.). Some data also supports oral nitroimidazole followed by intravaginal boric acid and suppressive metronidazole gel for recurrent BV (Reichman, O., R. Akins, and J.D. Sobel. 2009). Other recommendations that may be helpful include using condoms with male partners and avoiding douching.


Sex partners of women with vaginal trichomoniasis should be routinely evaluated and empirically treated. Sex partners of women with uncomplicated vulvovaginitis or BV need not be routinely evaluated or treated. However, women who have sex with women have a high prevalence of BV (for reasons that are not well understood) and BV is often present in both members of a female couple.  


Occasionally, vaginitis may become persistent or recurrent.  BV increases the risk of upper genital tract infection and of susceptibility to other STIs, including HIV.  In pregnant women,BV and trichomoniasis are associated with an increased risk of adverse outcomes, including premature rupture of membranes and low birth weight.

Hollman, D., et al. Screening for Trichomonas vaginalis in high-risk adolescent females with a new transcription-mediated nucleic acid amplification test (NAAT): associations with ethnicity, symptoms, and prior and current STIs. J Pediatr Adolesc Gynecol, 2010. 23(5): p. 312-6. [PubMed]

Kissinger, P., et al. A Randomized Treatment Trial: Single Versus 7 Day Dose of Metronidazole for the Treatment of Trichomonas Vaginalis among Hiv-Infected Women. J Acquir Immune Defic Syndr, 2010. 55(5): p. 565-571. [PubMed]

Reichman, O., R. Akins, and J.D. Sobel. Boric acid addition to suppressive antimicrobial therapy for recurrent bacterial vaginosis. Sex Transm Dis, 2009. 36(11): p. 732-4. [PubMed]

Schwebke, J.R. and F.J. Barrientes. Prevalence of Trichomonas vaginalis isolates with resistance to metronidazole and tinidazole. Antimicrob Agents Chemother, 2006. 50(12): p. 4209-10. [PubMed]

Sobel, J.D., et al., Suppressive antibacterial therapy with 0.75% metronidazole vaginal gel to prevent recurrent bacterial vaginosis. Am J Obstet Gynecol, 2006. 194(5): p. 1283-9. [PubMed]

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