Vaginitis: Diagnosis and Treatment (2024)

Vaginitis is defined as any condition with symptoms of abnormal vagin*l discharge, odor, irritation, itching, or burning. The most common causes of vaginitis are bacterial vaginosis, vulvovagin*l candidiasis, and trichom*oniasis. Bacterial vaginosis is implicated in 40% to 50% of cases when a cause is identified, with vulvovagin*l candidiasis accounting for 20% to 25% and trichom*oniasis for 15% to 20% of cases. Noninfectious causes, including atrophic, irritant, allergic, and inflammatory vaginitis, are less common and account for 5% to 10% of vaginitis cases. Diagnosis is made using a combination of symptoms, physical examination findings, and office-based or laboratory testing. Bacterial vaginosis is traditionally diagnosed with Amsel criteria, although Gram stain is the diagnostic standard. Newer laboratory tests that detect Gardnerella vagin*lis DNA or vagin*l fluid sialidase activity have similar sensitivity and specificity to Gram stain. Bacterial vaginosis is treated with oral metronidazole, intravagin*l metronidazole, or intravagin*l clindamycin. The diagnosis of vulvovagin*l candidiasis is made using a combination of clinical signs and symptoms with potassium hydroxide microscopy; DNA probe testing is also available. Culture can be helpful for the diagnosis of complicated vulvovagin*l candidiasis by identifying nonalbicans strains of Candida. Treatment of vulvovagin*l candidiasis involves oral fluconazole or topical azoles, although only topical azoles are recommended during pregnancy. The Centers for Disease Control and Prevention recommends nucleic acid amplification testing for the diagnosis of trichom*oniasis in symptomatic or high-risk women. Trichom*oniasis is treated with oral metronidazole or tinidazole, and patients' sex partners should be treated as well. Treatment of noninfectious vaginitis should be directed at the underlying cause. Atrophic vaginitis is treated with hormonal and nonhormonal therapies. Inflammatory vaginitis may improve with topical clindamycin as well as steroid application.

Vaginitis is characterized by vagin*l symptoms, including discharge, odor, itching, irritation, or burning.¹ Most women have at least one episode of vaginitis during their lives,² making it the most common gynecologic diagnosis in primary care. Studies have shown a negative effect on quality of life in women with vaginitis, with some women expressing anxiety, shame, and concerns about hygiene, particularly in those with recurrent symptoms.^3–8

The most common causes of vaginitis are bacterial vaginosis, vulvovagin*l candidiasis, and trichom*oniasis. Bacterial vaginosis is the cause in 40% to 50% of cases in which a cause is identified, with vulvovagin*l candidiasis accounting for 20% to 25% and trichom*oniasis for 15% to 20% of cases. Noninfectious causes, including atrophic, irritant, allergic, and inflammatory vaginitis, are less common and account for 5% to 10% of vaginitis cases.⁹

The history alone is unreliable for the diagnosis of different causes of vaginitis.¹⁰ Physical examination findings and office-based or laboratory test results should be used with the history to determine the diagnosis.^11–13 Characteristic clinical signs and symptoms for different causes of vaginitis are listed in Table 1.^10,14,15 Risk factors for vaginitis are listed in Table 2.^9,14,16

Signs and symptoms that increase the likelihood of vulvovagin*l candidiasis vs. bacterial vaginosis are a cheesy, curdy, or flocculent discharge; itching; vulvar or vagin*l inflammation or redness; and lack of odor.¹⁰ A fishy odor makes candidiasis less likely.¹⁰ Normal physiologic vagin*l discharge is clear to white, not malodorous, not accompanied by discomfort or pruritus, and the quantity varies during a woman's menstrual cycle.

Office-based tests include microscopy, measurement of vagin*l pH, and whiff test. A speculum is not required for collecting vagin*l fluid samples for these tests.¹⁷ Several studies have demonstrated a strong correlation between samples from patient self-collected swabs and those collected by clinicians for the diagnosis of bacterial vaginosis, with sensitivities of 70% to 100% and specificities of 97% to 100%.^18–22 It is reasonable to conclude that samples for office-based microscopy and laboratory testing for other causes of vaginitis can be collected by patients as well. Patients should be instructed to insert the swab at least one inch into the vagin*.

Although Gram stain is considered the diagnostic standard, bacterial vaginosis is traditionally diagnosed using the Amsel criteria (Table 3).^14,23 Criteria include thin, hom*ogenous discharge; a positive whiff test; the presence of clue cells on microscopy (Figure 1¹⁴ ); and a vagin*l pH greater than 4.5. Three out of four criteria are required to make the diagnosis, with sensitivity ranging from 70% to 97% and specificity from 90% to 94%, compared with Gram stain.^24,25 Newer methods of laboratory testing with DNA probe for Gardnerella vagin*lis or detection of vagin*l fluid sialidase activity have sensitivities of 92% to 100% and specificities of 92% to 98% compared with Gram stain.^26–28

vagin*l culture and Papanicolaou (Pap) testing are not useful for diagnosing bacterial vaginosis because it is a polymicrobial infection.⁹ Group B streptococcus may be found on culture and has been associated with vaginitis symptoms, although there is no expert consensus on treatment in nonpregnant women.²⁹

Recurrence of bacterial vaginosis is common. Women should be advised to return for treatment if symptoms recur. Routine testing in asymptomatic women and retesting (test of cure) are not recommended because these bacteria can be part of normal flora.

Vulvovagin*l candidiasis can be diagnosed by visualization of yeast hyphae on potassium hydroxide preparation (Figure 2¹⁴ ) in a woman with typical symptoms. It can also be diagnosed using antigen or DNA probe testing, with sensitivities of 77% to 97% and specificities of 77% to 99%, compared with culture as the diagnostic standard.^30–32 Women with vulvovagin*l candidiasis have a normal acidic vagin*l pH.

Complicated vulvovagin*l candidiasis is defined as recurrent (four or more episodes in one year) or severe infections, or infections that occur in a patient who is immunocompromised, such as someone with AIDS or poorly controlled diabetes mellitus. Culture is particularly important for the diagnosis and treatment of complicated vulvovagin*l candidiasis, because patients are more likely to have an infection with nonalbicans strains of Candida, which may require different treatment (Table 4).^9,16 Candidal species and anaerobes can be normal flora in asymptomatic women, so retesting (test of cure) is not recommended in the absence of symptoms.

Trichom*oniasis is a sexually transmitted infection that should be considered in women at risk who present with vaginitis symptoms (Table 2^9,14,16 ). It can be diagnosed when motile, flagellated protozoa are observed on saline microscopy (Figure 3¹⁴ ). However, the Centers for Disease Control and Prevention (CDC) recommends nucleic acid amplification testing for the diagnosis of trichom*oniasis in symptomatic or high-risk women. These tests have a higher sensitivity than saline microscopy (95% to 100% vs. 51% to 65%⁹) and can be performed on endocervical, vagin*l, or urine specimens, or on liquid-based Pap test samples. vagin*l culture also has a high sensitivity for identifying Trichom*onas, but it has largely been replaced by nucleic acid amplification testing because of the longer time (up to one week) needed for results.⁹

Because trichom*oniasis is sexually transmitted and has a high rate of recurrence, the CDC recommends testing for reinfection three months after treatment.⁹

Some data show that newer laboratory tests such as DNA and antigen testing for bacterial vaginosis and vulvovagin*l candidiasis, or vagin*l fluid sialidase testing for bacterial vaginosis, may have similar or better sensitivity and specificity compared with office-based testing.³³ However, more comparisons with diagnostic standard testing (i.e., Gram stain for bacterial vaginosis and culture for vulvovagin*l candidiasis) are needed. The costs of these tests range from approximately $17 for vagin*l fluid sialidase testing to $27 to $49 for DNA testing, compared with $5 to $10 for office-based microscopy. No studies were found on the cost-effectiveness of these newer tests compared with office-based testing.

When clue cells or hyphae are present on a Pap test, treatment depends on symptoms. Both can be normal findings in asymptomatic women.⁹ Also, physicians should treat trichom*oniasis when found on a Pap test, but a normal result does not rule out infection.³⁴ When seeking a diagnosis for vagin*l symptoms at the same time as performing a Pap test, physicians can order testing on the liquid-based Pap fluid. These tests have similar sensitivity and specificity to vagin*l samples.

There is no cause of vaginitis identified in up to 30% of women. These women may have a range of conditions, including irritant or allergic vaginitis, atrophic vaginitis, or physiologic discharge.³⁵ Inflammatory vaginitis is an uncommon condition characterized by purulent discharge, burning, and dyspareunia, and should be considered in patients with these symptoms if no infectious cause is found. Inflammatory vaginitis is associated with low estrogen levels, such as in menopausal or perimenopausal women.³⁶

First-line and alternative treatment regimens for vaginitis are presented in Table 4 with suggestions for recurrent infection, treatment during pregnancy, and treatment of sex partners.^9,16 Additional considerations for the treatment of bacterial vaginosis, vulvovagin*l candidiasis, and trichom*oniasis are discussed.

Treatment of bacterial vaginosis is recommended for resolving symptoms, as well as reducing the risk of Chlamydia trachomatis, Neisseria gonorrhoeae, Trichom*onas vagin*lis, human immunodeficiency virus (HIV), and herpes simplex virus type 2 infections.³⁷ Shifts in vagin*l flora have been associated with increased risk of these infections, leading researchers to conclude that treatment of bacterial vaginosis may decrease susceptibility to these infections.^38,39

First-line therapy includes seven-day courses of oral metronidazole (Flagyl), intravagin*l metronidazole (Metrogel), or intravagin*l clindamycin.⁹ No significant difference in effectiveness has been demonstrated among these regimens.⁴⁰ Patient preference should be considered when choosing an agent. Physicians should explain potential adverse effects with each regimen, including a possible disulfiram-like reaction with alcohol consumption or gastrointestinal symptoms in persons taking oral metronidazole, or possible weakening of latex condoms with the use of topical therapies containing oil-based preparations.⁹

The U.S. Food and Drug Administration recently approved a single-dose oral therapy for bacterial vaginosis, secnidazole (Solosec), which will be available in 2018.⁴¹ A randomized controlled trial demonstrated similar effectiveness and outcomes compared with metronidazole for the treatment of bacterial vaginosis.⁴² The dosing involves one-time oral administration of a 2-g packet of granules mixed into applesauce, yogurt, or pudding. A primary adverse effect of this regimen is vulvovagin*l candidiasis. Data are insufficient on the safety of secnidazole use in pregnancy, and use is not recommended with breastfeeding.⁴³

Bacterial Vaginosis in Pregnancy. In the past, treatment for bacterial vaginosis during pregnancy was recommended to prevent preterm births. Further review of the evidence has demonstrated that antibiotic treatment does not prevent preterm birth for women with symptomatic or asymptomatic bacterial vaginosis.^44,45 Although a previous meta-analysis demonstrated a possible reduction in preterm labor with treatment of bacterial vaginosis, particularly in early pregnancy (before 20 weeks' gestation),⁴⁶ a more recent meta-analysis of 21 studies found that antibiotic treatment—regardless of route of administration (oral or topical), the timing in pregnancy, or history of preterm labor in previous pregnancies—does not prevent preterm birth for women with symptomatic or asymptomatic bacterial vaginosis.⁴⁵ Two studies cited in this meta-analysis that included the presence of abnormal vagin*l flora as well as bacterial vaginosis showed a possible reduction in preterm labor before 37 weeks' gestation with treatment; therefore, further investigation may provide more information about the role of abnormal bacterial flora and its treatment in pregnancy.⁴⁵ Regardless, treatment of bacterial vaginosis is generally recommended for symptomatic relief, and adverse effects of metronidazole in pregnancy have not been demonstrated.⁴⁵

Treatment of candidal infection is aimed at reducing symptoms. There are several topical azole preparations and regimens available, as well as oral fluconazole (Diflucan) in a single 150-mg dose. All topical treatments listed in Table 5,^9,16 as well as oral fluconazole, are recommended by the CDC as first-line therapy for vulvovagin*l candidiasis.⁹ The choice of treatment should be made in conjunction with patient preference and previous experience with these agents. In nonpregnant patients, there is no definitive advantage of one treatment over another in terms of clinical or mycologic cure, with all treatment options having about an 80% cure rate.^47,48 Limited data demonstrate that patients may prefer oral regimens.^49–51

There are several considerations when choosing between topical and oral treatment.^52,53 Topical preparations may provide more immediate relief because of the soothing nature of topical treatment or, conversely, may cause local hypersensitivity reactions resulting in itching or burning. Oral fluconazole offers the advantage of one-dose convenience without messy creams or suppositories. Oral medications may cause systemic adverse effects, particularly gastrointestinal effects and toxicity in addition to potential medication interactions. An additional factor to consider is that topical azole creams and suppositories may be oil-based and can weaken latex condoms.⁹

Topical antifungals are available over the counter, and many patients self-diagnose and treat presumed vulvovagin*l candidiasis with these products. However, studies have shown that, regardless of whether they have a history of vulvovagin*l candidiasis, women are not able to accurately self-diagnose the condition, often using these products for causes of vaginitis other than candidal infections.⁵⁴

Vulvovagin*l Candidiasis in Pregnancy. Vulvovagin*l candidiasis is common during pregnancy. The CDC recommends that only topical azole therapies, applied for seven days, be used in pregnant women with vulvovagin*l candidiasis.⁹ Although more data are needed, oral therapy may be associated with increased risk of miscarriage or fetal malformations, particularly at high doses.^55,56

Complicated Vulvovagin*l Candidiasis. Patients with complicated vulvovagin*l candidiasis require more aggressive therapy. To guide treatment, it is helpful to consider whether a patient has recurrent infections and whether the etiology may be a nonalbicans species of Candida.

For patients with severe vulvovagin*l candidiasis, a second dose of fluconazole given three days after the first dose has been shown to achieve significant improvement in short-term symptoms as well as prevent recurrence at 35 days. A second dose did not have significant effects for recurrent vulvovagin*l candidiasis.⁵⁷

For recurrent vulvovagin*l candidiasis caused by Candida albicans, initial intensive therapy with fluconazole for seven to 14 days (i.e., fluconazole, 150 mg, every three days for three doses) followed by weekly treatment with 150-mg fluconazole for six months has been shown to achieve symptomatic relief at one year for most patients.⁵⁸

If severe or recurrent vulvovagin*l candidiasis does not respond to initial treatment, culture may guide therapy when nonalbicans species are identified. Infections with nonalbicans species are less responsive to fluconazole. Topical imidazoles (i.e., econazole, clotrimazole, miconazole, and ketoconazole) are more effective in eradication.⁵⁹ In a small study, topical terconazole was also shown to relieve symptoms and achieve mycologic cure for about 50% of patients.⁶⁰ For patients with nonalbicans infections who do not respond to these treatments, a regimen of 600-mg vagin*l boric acid capsules daily for 14 days has been shown to be effective.⁶¹

Other nonpharmacologic regimens have been proposed for recurrent vulvovagin*l candidiasis. A meta-analysis did not demonstrate clear evidence for probiotics in the treatment of candidal vaginitis; however, more studies are needed because of small study size and varied probiotic regimens.⁶²

Treatment of trichom*oniasis can decrease symptoms and reduce transmission to partners. In addition, in persons with HIV infection, treatment of trichom*oniasis may also decrease HIV transmission rates to partners.⁶³

Although first-line therapy for trichom*oniasis in pregnant and nonpregnant women is a single 2-g dose of metronidazole, patients with HIV infection treated with a seven-day course of metronidazole had lower rates of infection at test of cure and lower rates of reinfection at three months.^9,64 Tinidazole (Tindamax) in a single 2-g dose is also a first-line treatment for trichom*oniasis; however, it is more expensive. Metronidazole-resistant trichom*oniasis, which would require tinidazole, is rare.⁶⁵

Trichom*oniasis in Pregnancy. Trichom*oniasis has been associated with adverse pregnancy outcomes, including low birth weight and preterm birth.⁶⁶ Symptomatic pregnant women, regardless of pregnancy stage, should be tested and considered for treatment.

Treatment of noninfectious vaginitis should be directed at the underlying cause. Atrophic vaginitis is treated with hormonal and nonhormonal therapies. Among hormonal therapies, low-dose vagin*l estrogen preparations are available in creams, tablets, and rings. Systemic estrogen therapies are also available for patients with vasomotor symptoms.⁶⁷ First-line nonhormonal treatment recommendations include vagin*l lubricants and moisturizers; continued sexual activity should be encouraged.⁶⁸

More research is needed to better characterize the cause and treatment of inflammatory vaginitis. Some studies have demonstrated improvement in symptoms with application of topical clindamycin or steroids; however, the ideal duration of treatment and superiority of one agent over the other have not been established.^35,36