Vaginal discharge is a common presenting symptom and may be either physiological or pathological. Many cases of vaginal discharge are not caused by sexually transmitted diseases (STDs) but still require treatment. Sexually transmitted infections may also present with vaginal discharge.

A normal physiological discharge is a white or clear, non-offensive discharge that varies with the menstrual cycle.¹

Causes of vaginal discharge

• Noninfective:
  • Physiological.
  • Cervical polyps and ectopy.
  • Foreign bodies, e.g. retained tampon.
  • Vulval dermatitis.
  • Erosive lichen planus.
  • Genital tract malignancy (cancer of cervix, cancer of uterus, ovarian cancer).
  • Fistulae.
• Nonsexually transmitted infection:
  • Bacterial vaginosis - is most commonly seen in sexually active women who have a concurrent sexually transmitted disease.
  • Candidal infections - caused by an an overgrowth of Candida albicans.
• Sexually transmitted infection:
  • Chlamydia trachomatis.
  • Neisseria gonorrhoeae.
  • Trichomonas vaginalis - particularly common in young women attending the genitourinary medicine (GUM) clinic and is frequently found in association with infection with N. gonorrhoeae.

Physiological discharge

• Newborn infants may have a small amount of vaginal discharge, sometimes mixed in with a little blood, due to high levels of circulating maternal oestrogen.² This should disappear by two weeks of age.
• During the reproductive years the fluctuating levels of oestrogen and progesterone throughout the menstrual cycle affect the quality and quantity of cervical mucus which is perceived by women as a change in their vaginal discharge. Initially, when oestrogen is low, the mucus is thick and sticky. As oestrogen levels rise, the mucus gets progressively clearer, wetter and more stretchy. After ovulation, there is an increase in the thickness and stickiness of the mucus once more.
• At menopause the normal amount of vaginal discharge decreases as oestrogen levels fall.

Epidemiology

• The most common cause of pathological vaginal discharge in women of childbearing age is bacterial vaginosis which occurs twice as frequently as vaginal candidiasis.^3,4
• 50% of cases of bacterial vaginosis are asymptomatic so the true prevalence is unknown.³
• The most common infective cause is vulvovaginal candidiasis which affects about 75% of women at some point during their reproductive life. 40-50% have two or more episodes and 10-20% may harbour Candida spp. asymptomatically at any one time.⁵

Assessment⁶

• A full clinical and sexual history should be sought with a particular note of the nature of the discharge (what has changed, odour, onset, duration, colour, consistency) and associated symptoms (these may include itch, superficial dyspareunia or dysuria, abdominal pain, deep dyspareunia, abnormal bleeding, dysuria, pyrexia).
• Also consider concurrent medications (e.g. antibiotics, corticosteroids), previous treatments used (prescription and over-the-counter), and medical conditions (e.g. diabetes, immunocompromised state).
• Symptoms suggesting that discharge is abnormal include:
  • A discharge that is heavier than usual.
  • A discharge that is thicker than usual.
  • Pus-like discharge.
  • White and clumpy discharge.
  • Greyish, greenish, yellowish, or blood-tinged discharge.
  • Foul-smelling (fishy or rotting meat) discharge.
  • A discharge accompanied by bloodiness, itching, burning, a rash, or soreness.

Presentation

Infective (nonsexually transmitted) vaginal discharge

• Bacterial vaginosis:
  • Causes a thin, profuse and fishy-smelling discharge without itch or soreness.
• Candidiasis:
  • Thick, white, non-offensive discharge which is associated with vulval itch and soreness.
  • May cause mild dyspareunia and external dysuria

Infective (STD) vaginal discharge⁷

C. trachomatis, N. gonorrhoeae, and T. vaginalis can present with vaginal discharge but may also be asymptomatic. They are associated with an increased risk of HIV transmission.¹

• T. vaginalis:
  • May cause an offensive yellow vaginal discharge, which is often profuse and frothy, associated with vulval itch and soreness, dysuria, abdominal pain and superficial dyspareunia.
• C.trachomatis:
  • May cause a copious purulent vaginal discharge, but it is asymptomatic in 80% of women.
• N. gonorrhoeae:
  • May present with a purulent vaginal discharge but is asymptomatic in up to 50% of women¹

Noninfective causes of vaginal discharge

• Retained foreign bodies - result in a foul-smelling serosanguinous discharge. Diagnosis is confirmed on examination.
• Cervical polyps and ectopy - tend to be asymptomatic but there may be increased discharge and intermenstrual bleeding. Diagnosis is made on speculum examination.
• Genital tract malignancy - presentation varies and, in some cases, a persistent vaginal discharge not responding to conventional treatment may be the first clue. Diagnosis is made on examination and biopsy.
• Fistulae - history of trauma or surgery is suggestive. There may be a foul or feculent discharge in association with recurrent urinary tract infections.
• Allergic reactions - diagnosis is suspected on taking the history, e.g. use of irritant chemicals in douching, contact with latex and semen.

Vaginal discharge in pregnancy^6,8

The quality and quantity of vaginal discharge often changes during pregnancy with most women producing more discharge during pregnancy.

• Bacterial vaginosis:
  • Is associated with late miscarriage, preterm labour, premature rupture of membranes, low birthweight and postpartum endometritis.
  • Routine screening during pregnancy is not yet recommended and current guidelines support screening only for women with a previous preterm birth (prior to 28 weeks' gestation) or second-trimester miscarriage.
• Candidiasis - common in pregnancy (30-34%) and often asymptomatic.⁵ There is no evidence of any harm to the fetus.
• T. vaginalis - increasingly thought to be associated with preterm delivery and low birthweight.

Vaginal discharge following miscarriage, abortion or delivery

• These patients should be fully investigated and empirically treated whilst awaiting results of swabs.
• Bacterial vaginosis is associated with endometritis and pelvic inflammatory disease following abortion but retained products of conception should be considered in all women, particularly in the presence of a heavy growth of coliforms.

Investigations

• Patients who present with symptoms suggestive of bacterial vaginosis or vulvovaginal candidiasis can be treated without sampling.⁶
• Otherwise 'triple swabs' should be taken:
  • High vaginal swab to identify bacterial vaginosis, candidal infections, and T. vaginalis.
  • Endocervical swab in transport medium (charcoal or non-charcoal) to diagnose gonorrhoea.
  • Endocervical swab for a chlamydial DNA amplification test to diagnose C. trachomatis.
• Vaginal pH testing (using narrow range pH paper) is a quick, cheap, and simple test that can help discriminate between bacterial vaginosis (pH 4.5 or above) and vulvovaginal candidiasis (pH <4.5).¹

Management

• Take history with particular care to elicit clues suggestive of the presence of an STD. If there are suggestions that there might be an STD or for recurrent infections, refer to the genitourinary medicine (GUM) clinic.
• The finding of an STD should prompt patient education and counselling, screening for other STDs and sexual contact tracing for testing and appropriate management.

Infective (nonsexually transmitted) and sexually transmitted causes of vaginal discharge

See individual records for management.

Non-infective causes of vaginal discharge

• Retained foreign bodies:
  • Most can be manually removed but these may occasionally be very small (fibrous material or small beads in a child's vagina, a small piece of torn condom) and so not readily visible and require a lavage (in children this may require sedation).
  • Where larger or irregularly shaped objects cause spasm of the vaginal walls, sedation or anaesthesia may also be needed.
  • A short course of antibiotics may be needed if the object was there long enough to cause secondary infection.
• Cervical polyps and ectopy - excision of larger symptomatic or suspicious-looking polyps may be necessary.
• Allergic reactions - treatment includes identifying and removing the cause.

Management of recurrent discharge

The general advice is the same as for acute infection but see individual articles for detailed advice.

Management of persistent discharge³⁶

• In some cases, repeated examination and screening yield no positive results, yet the patient still complains of vaginal discharge.
• It is then appropriate to explore with the patient the nature of the discharge and relate this to normal physiological discharge, to review personal hygiene habits (advise to avoid douches, perfumed products and tight synthetic clothing) and to explore the possibility of the 'silent' complaint, such as depression, anxiety or psychosexual dysfunction.
• Postmenopausal atrophic changes may predispose women to repeated episodes of vaginitis which may respond well to hormonal creams or pessaries.

Complications

• Untreated, simple vaginal infection can spread to the upper reproductive tract and cause more serious illness and, in the long-term, infertility.
• The same can be said of a retained foreign body with the potential of developing toxic shock syndrome.
• Cervical polyps are generally harmless although may cause infertility if they grow very large.
• There are specific complications associated with infective discharge in pregnancy, as outlined above.

Prognosis⁶

• Bacterial vaginosis has a 70-80% cure rate with the above regimen after one course of treatment (but it commonly recurs).
• Candidiasis has a cure rate of 80-95%.
• Trichomoniasis has a 95% cure rate.⁹

Prevention

• Good basic personal hygiene (cleanliness without the use of douches and perfumed chemical agents) with avoidance of tight, synthetic clothing.
• Treatment of sexual partners.

Document references

1. Spence D, Melville C; Vaginal discharge. BMJ. 2007 Dec 1;335(7630):1147-51.
2. The Merck Manual; Symptoms and diagnosis of gynecologic disorders. Last updated February 2003
3. Mitchell H; Vaginal discharge - causes, diagnosis and treatment. BMJ 2004; 328: 1306-1308.
4. Vaginal discharge - guideline for primary care, Health Protection Agency (October 2009); Quick reference guide for primary care
5. Management of vulvovaginal candidiasis, British Association for Sexual Health and HIV (2007)
6. The management of women of reproductive age attending non-genitourinary medicine settings complaining of vaginal discharge, Faculty of Family Planning and Reproductive Health Care Clinical Effectiveness Unit (2006); (PDF)
7. Vaginal discharge, Clinical Knowledge Summaries (January 2009)
8. Antenatal care: routine care for the healthy pregnant woman, NICE Clinical Guideline (March 2008)
9. Management of Sexually Transmitted Infections and Related Conditions in Children and Young People, British Association for Sexual Health and HIV (2009)

Internet and further reading

• World Health Organization; Treatment flowchart: vaginal discharge in pregnancy and postpartum period

Acknowledgements