Assessment of vaginal discharge

Overview 
Theory 
Emergencies 
Diagnosis 
Resources 

Vaginal discharge is a common symptom seen by clinicians. It may be physiological or pathological.[9] British Association for Sexual Health and HIV (BASHH) guidelines Opens in new window

Physiological discharge can vary in character with changes in age (pre-pubertal, reproductive, or post-menopausal), hormones (during pregnancy or when using hormonal contraception), or local factors such as menstruation, intrauterine device, or postnatal state.[1][10]
Pathological causes are commonly due to infection: mainly bacterial vaginosis, vulvovaginal candidiasis (VVC), and trichomoniasis, which together account for 90% of vaginitis cases.[11] Non-infectious causes include genitourinary syndrome of menopause (GSM), desquamative inflammatory vaginitis, dermatitis, foreign body, allergens, and inadequate hygiene.[12][13][14]

Bacterial vaginosis

Bacterial vaginosis is the most common vaginal infection, with a prevalence of 21.2 million (29.2%) in the US in women aged 14 to 49 years.[15] Among community-dwelling older women in the US (aged 62-90 years), bacterial vaginosis prevalence has been reported to be 38%.[16] Global prevalence is high, ranging from 20% to 60% across regions.[17][18]

Bacterial vaginosis is characterised by a complex change in the vaginal flora, which leads to a reduction of the normally dominant lactobacilli.[19] These lactobacilli are replaced by an increased concentration of other organisms, especially anaerobes such as Gardnerella vaginalis, Mycoplasma hominis, Prevotella species, Porphyromonas species, Bacteroides species, anaerobic Peptostreptococcus species, Fusobacterium species, or Atopobium vaginae.[20] These organisms, which break down vaginal peptides into amines and cause the typical discharge in patients with bacterial vaginosis, produce large amounts of proteolytic carboxylase enzymes.

Patients treated for bacterial vaginosis have a high risk of recurrence within 3 months.[21][22] Routine treatment of women with asymptomatic bacterial vaginosis is not recommended, mainly due to low response rates and increased incidence of candidiasis after therapy.[23] However, treatment of asymptomatic women with bacterial vaginosis results in a lower rate of subsequent Chlamydia infection.[23]

Bacterial vaginosis infection is associated with objective evidence of acute upper genital tract infection, vaginal cuff cellulitis, abscess after transvaginal hysterectomy, post-voluntary termination of pregnancy, endometritis, and pelvic inflammatory disease.[24][25][26] Treatment of male partners of patients with bacterial vaginosis does not increase the cure rate; therefore, it is not routinely recommended.[9][27][28]

Bacterial vaginosis in pregnancy is a risk factor for preterm premature rupture of membranes, preterm delivery, low birth weight, and spontaneous abortion.[9][29][30] Antibiotic therapy effectively eradicates bacterial vaginosis during therapy, but does not prevent preterm birth.[31][32] Currently, in the general obstetric population, data are insufficient to support screening for or treatment of bacterial vaginosis to reduce risk for preterm birth.[9][31][32][33][34][Figure caption and citation for the preceding image starts]: Photomicrograph revealing bacteria adhering to vaginal epithelial cells, known as clue cellsCDC Image Library; M. Rein [Citation ends]. com.bmj.content.model.assessment.Caption@7f090e6b

Trichomoniasis

Trichomonas vaginalis (TV), a flagellated protozoan parasite, causes trichomoniasis. It accounts for 4% to 35% of vaginitis in symptomatic women, and is considerably more common in black women than in white women.[9][35]

Trichomoniasis is estimated to be the most prevalent non-viral sexually transmitted infection (STI) worldwide, affecting approximately 2.1% of females in the US.[9] TV is usually found in the vagina, urethra, and paraurethral glands of infected patients.[36][37] It is associated with a high prevalence of co-infection with other STIs.

Concurrent treatment of sex partners is recommended.[9][27][37][38] Trichomoniasis is associated with a 1.5-fold increased risk for HIV-1 acquisition; it may also enhance genital shedding of HIV in women (which may be reduced by treatment).[9][39][40][41] Screening for trichomoniasis is recommended for women living with HIV, and might be considered for those receiving care in high-prevalence settings (e.g., sexually transmitted disease clinics and correctional facilities) or at high risk for infection (e.g., multiple sexual partners, transactional sex, drug misuse, or history of STIs or incarceration).[9]

Trichomoniasis is associated with adverse pregnancy outcomes such as preterm birth, but treatment has not been shown to reduce perinatal morbidity.[9]

[Figure caption and citation for the preceding image starts]: Phase contrast wet mount micrograph of a vaginal discharge revealing the presence of Trichomonas vaginalisprotozoa CDC Image Library [Citation ends]. com.bmj.content.model.assessment.Caption@61352eab [Figure caption and citation for the preceding image starts]: Trichomonasvaginitis with copious purulent discharge emanating from the cervical os CDC Image Library [Citation ends].

Vulvovaginal candidiasis

Candida causes one-third of vaginitis cases, and is one of the most common genital infections seen in clinical practice.[42][43]Candida species are present in about 20% to 50% of vaginal flora of healthy asymptomatic women. VVC is common in adults, especially pre-menopausal women. VVC is less common in post-menopausal and peri-menopausal patients. The global annual prevalence of recurrent VVC has been reported to be 3871 per 100,000 women.[44] VVC is not considered an STI.

Candida albicans is the most common cause of VVC. Candida glabrata and Candida parapsilosis can cause VVC with milder symptoms. Symptomatic disease occurs due to a complex interplay between host inflammatory response and yeast virulence factors. Two-thirds of women who self-diagnose VVC and self-treat are found not to have VVC.[45]

Risk factors for VVC include diabetes mellitus, broad-spectrum antibiotics that inhibit growth of normal vaginal flora, high oestrogen levels (e.g., when using combined hormonal contraception, menopausal hormone therapy, or during pregnancy), immunosuppression (including patients with HIV, in whom it is associated with a higher incidence and persistence of disease), and genetic susceptibility.[9][46][47] VVC is not related to number of recent sexual partners but may be related to increased frequency of intercourse.[48]

VVC can be classified as uncomplicated or complicated.[9][38][49]

Uncomplicated VVC:

Sporadic or infrequent VVC
Mild to moderate symptoms
Likely to be C albicans species
Presence in an immunocompetent patient

Complicated VVC:

Recurrent VVC (4 or more episodes of symptomatic VVC in <1 year, with 2 episodes confirmed by microscopy or culture when symptomatic (at least one must be culture)[50]

Includes patients with severe VVC, non-albicans candidiasis, uncontrolled diabetes, immunodeficiency, or immunosuppressive therapy
Complicated VVC is characterised by an increased incidence of candida species other than C albicans in patients with HIV and patients with recurrent candidiasis[Figure caption and citation for the preceding image starts]: Vaginal smear identifying Candida albicans using a wet mount technique CDC Image Library; Dr Stuart Brown [Citation ends].[Figure caption and citation for the preceding image starts]: Vaginal smear identifying Candida albicans using Gram stain technique CDC Image Library; Dr Stuart Brown [Citation ends].

Mycoplasma genitalium

M genitalium is associated with cervicitis and pelvic inflammatory disease (PID) in women. Symptoms include vaginal discharge, dysuria, or symptoms of PID (abdominal pain and dyspareunia), but asymptomatic infection is common.[9][51] Transmission of M genitalium is through direct mucosal contact.

European guidelines recommend testing for M genitalium in women with:[51]

symptoms and signs of M genitalium (mucopurulent cervicitis, intermenstrual or post-coital bleeding, dysuria with no known other aetiology, acute pelvic pain and/or PID)
on-going sexual contacts of persons being treated for M genitalium infection.

Before termination of pregnancy, testing may be considered.[51]

US guidelines recommend that women with recurrent cervicitis should be tested for M genitalium, and that testing should be considered among women with PID.[9]

European and US guidelines recommend that:[9][51]

current sex partners of M. genitalium-positive patients should be tested
all M genitalium-positive tests should be followed up with macrolide resistance testing, when available.

Less common infectious causes

Other, less common infectious causes of vaginitis include chlamydial infection, gonorrhoeal infection, herpes simplex virus, streptococcal infection, genital schistosomiasis (reported in Africa), and Entamoeba gingivalis infection (associated with intrauterine device use).[52][53][54][55][56][Figure caption and citation for the preceding image starts]: McCoy cell monolayer micrograph revealing intracellular Chlamydia trachomatis inclusion bodies; magnified 50x CDC; Dr E. Arum, Dr N. Jacobs [Citation ends]. com.bmj.content.model.assessment.Caption@3676dcaf [Figure caption and citation for the preceding image starts]: Micrograph of polymorphonuclear leukocytes and (extracellular) diplococci on a cervical smearCDC Image Library; Joe Miller [Citation ends].[Figure caption and citation for the preceding image starts]: Cervicitis and vaginal discharge due to gonorrhoeaCDC Image Library [Citation ends]. com.bmj.content.model.assessment.Caption@674322fa [Figure caption and citation for the preceding image starts]: Cervicitis due to herpes simplex virus; erosive inflammation with accompanying paracervical purulency is seenCDC; Dr Paul Wiesner [Citation ends].

Non-infectious causes

Include allergy or contact dermatitis (e.g., latex, sperm, douching, dyes), chemical irritants (e.g., soaps, tampons, pads, condoms), inadequate hygiene, GSM (oestrogen deficiency), foreign body (e.g., tampons, pessary, combined hormonal rings), erosive lichen planus, postpuerperal atrophic vaginitis, desquamative inflammatory vaginitis (chronic and intractable vaginitis associated with purulent and copious discharge), pelvic irradiation, Behcet's syndrome (inflammation of the vasculature; symptoms include sores and painful swollen joints), graft versus host disease, and genital tract cancer.[52][57][58]

A complication of intravaginal slingplasty can include purulent and offensive vaginal discharge from mesh erosion.[59] In April 2019, the US Food and Drug Administration (FDA) prohibited sales and distribution of surgical mesh intended for transvaginal repair of anterior compartment prolapse (cystocele).[60] In October 2022, the FDA published a statement maintaining that these devices do not have a favourable benefit-risk profile.[61] In the UK, the use of surgical mesh/tape for urogynaecological prolapse, where the mesh is inserted through the vaginal wall, is currently restricted while an independent review takes place. In July 2018, NHS England advised that the use of vaginally inserted surgical mesh for pelvic organ prolapse should be postponed if it is clinically safe to do so.[62][63][64][65]

Other less common causes of vaginal discharge reported in the literature include prolapsing fibroid and vaginal fistula.[66][67]

Paediatric

Compared with the vagina of a woman of reproductive age, the vagina of a pre-pubertal patient is:

of neutral pH, without antibodies to protect it from infection
shorter and closer to the rectum
exposed to much lower oestrogen levels

For these reasons, this age group is at increased risk for vulvovaginitis (which accounts for approximately 60% to 70% of all gynaecological complaints in the paediatric population).[66][67][68][69] Vaginal discharge in this age group is usually not caused by infection, and almost never caused by a malignancy.[70]

Causes of vaginal discharge in young girls include foreign body (45%), sexual abuse (18%), and unknown diagnosis (36%).[71][72] Other causes comprise non-specific vaginitis (irritation from bubble baths, perfumed soaps, tight-fitting clothes, back-to-front wiping, poor wiping after toilet training), streptococcal vaginitis (accompanies or follows a symptomatic streptococcal pharyngitis), and physiological changes (endogenous hormones 6-12 months before menarche).

Infectious causes in paediatric patients can include pinworms, transmission of infection from mother's birth canal up to a year after birth, group A beta-haemolytic streptococci, Haemophilus influenzae, and some Gram-negative bacilli. Diagnosis of Neisseria gonorrhoeae or Chlamydia trachomatis implies sexual abuse.[73] Blood-stained discharge requires referral for vaginoscopy.

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