Vulvovaginitis: Find the cause to treat it
ABSTRACT
Vulvar and vaginal disorders are among the most common problems seen in ambulatory care. The cause is usually infectious, but noninfectious causes should also be considered, and differentiating them can be challenging. Accurate diagnosis based on patient history, physical examination, and laboratory testing is necessary so that effective therapy can be chosen.
KEY POINTS
- Typical presenting symptoms of vulvovaginitis are itching, burning, and abnormal discharge.
- Evaluating vaginal secretions with simple office-based tools is often sufficient for diagnosis, although DNA testing is also available.
- Depending on the cause, vulvovaginitis is generally treated with a course of oral or topical antibiotics, antiviral or antifungal drugs, anti-inflammatory agents, or hormonal therapy.
- Cases that do not resolve may require maintenance therapy. Patients who have persistent or unusual symptoms should be referred to a specialist.
TRICHOMONIASIS
The incidence of T vaginalis infection is higher than that of Neisseria gonorrhoeae and Chlamydia trachomatis combined, with an estimated 7.4 million new cases occurring in the year 2000 in the United States.17 Infection increases the sexual transmission of HIV.18–20 It is often asymptomatic and so is likely underdiagnosed.
Diagnosis of trichomoniasis
Vaginal pH may be normal or elevated (> 4.5).
Direct microscopy. Observation by saline microscopy of motile trichomonads with their characteristic jerky movements is 100% specific but only 50% sensitive. Sensitivity is reduced by delaying microscopy on the sample by as little as 10 minutes.21
The incidental finding of T vaginalis on a conventional Papanicolaou (Pap) smear has poor sensitivity and specificity, and patients diagnosed with T vaginalis by conventional Pap smear should have a second test performed. The liquid-based Pap test is more accurate for microscopic diagnosis, and its results can be used to determine if treatment is needed (sensitivity 60%–90%; specificity 98%–100%).22,23
Culture. Amplification of T vaginalis in liquid culture usually provides results within 3 days.24 It is more sensitive than microscopy but less sensitive than a nucleic acid amplification test: compared with a nucleic acid amplification test, culture is 44% to 75% sensitive for detecting T vaginalis and 100% specific.19 Culture is the preferred test for resistant strains.
Non–culture-based or nucleic acid tests do not require viable organisms, so they allow for a wider range of specimen storage temperatures and time intervals between collection and processing. This quality limits them for testing treatment success; if performed too early, they may detect nonviable organisms. A 2-week interval is recommended between the end of treatment and retesting.25
Nonamplified tests such as Affirm VPIII and the Osom Trichomonas Test (Sekisui Diagnostics, Lexington, MA) are 40% to 95% sensitive, depending on the test and reference standard used, and 92% to 100% specific.26,27
Nucleic acid amplification tests are usually not performed as point-of-care tests. They are more expensive and require special equipment with trained personnel. Sensitivities range from 76% to 100%, making these tests more suitable for screening and testing of asymptomatic women, in whom the concentration of organisms may be lower.
Treatment of trichomoniasis
Treatment is a single 2-g oral dose of metronidazole or tinidazole.9
If initial treatment is ineffective, an additional regimen can be either of the following:
- Oral metronidazole 500 mg twice a day for 7 days
- Oral metronidazole or tinidazole, 2 g daily for 5 days.
Patients allergic to nitroimidazoles should be referred for desensitization.
If these treatments are unsuccessful, the patient should be referred to an infectious disease specialist or gynecologist who specializes in vulvovaginal disorders. Treatment failure is uncommon and is usually related to noncompliance, reinfection, or metronidazole resistance.28 The US Centers for Disease Control and Prevention offers testing for resistance by request.
Reportedly successful regimens for refractory trichomoniasis include 14 days of either:
- Oral tinidazole 500 mg 4 times daily plus vaginal tinidazole 500 mg twice daily29
- Oral tinidazole 1 g 3 times daily plus compounded 5% intravaginal paromomycin 5 g nightly.30
HERPES SIMPLEX VIRUS INFECTION
HSV (HSV-1 and HSV-2) causes lifelong infection. About 50 million people in the United States are infected with HSV-2, the most common cause of recurrent infections.31 Owing to changes in sexual practices, an increasing number of young people are acquiring anogenital HSV-1 infection.32,33
Diagnosis of herpes
Diagnosis may be difficult because the painful vesicular or ulcerative lesions (Figure 4) may not be visible at the time of presentation. Diagnosis is based on specific virologic and serologic tests. Nonspecific tests (eg, Tzanck smear, direct immunofluorescence) are neither sensitive nor specific and should not be relied on for diagnosis.34 HSV culture or HSV-PCR testing of a lesion is preferred. The sensitivity of viral culture can be low and is dependent on the stage of healing of a lesion and obtaining an adequate sample.
Accurate type-specific HSV serologic assays are based on HSV-specific glycoprotein G1 (HSV-1) and glycoprotein G2 (HSV-2). Unless a patient’s serologic status has already been determined, serologic testing should be done concurrently with HSV culture or PCR testing. Serologic testing enables classification of an infection as primary, nonprimary, or recurrent. For example, a patient with a positive HSV culture and negative serology most likely has primary HSV infection, and serologic study should be repeated after 6 to 8 weeks to assess for seroconversion.
Immunoglobulin M (IgM) testing for HSV-1 or HSV-2 is not diagnostic or type-specific and may be positive during recurrent genital or oral episodes of herpes.35
Treatment of herpes
In general, antiviral medications (eg, acyclovir, valacyclovir, famciclovir) are effective for managing HSV.12 Episodic or continuous suppression therapy may be needed for patients experiencing more than four outbreaks in 12 months. Patients who do not respond to treatment should be referred to an infectious disease specialist and undergo a viral culture with sensitivities.
