Women of reproductive age have a normal physiological vaginal discharge with cyclical variation.
About four days before ovulation, the discharge is thin, stretchy and clear (estrogenic effect). In the second half of the menstrual cycle, the discharge is thick, white and not stretchy (progesterone effect).
Normal vaginal flora (lactobacilli) colonise the vaginal epithelium and may have a role in defending against infection.
These bacteria produce lactic acid by metabolism of glycogen under the effect of estrogen. The low pH protects the vagina and uterus from pathogens.
Discharge is not normally seen in pre-pubertal patients. When it occurs in this age group, it is usually due to faecal organisms.1
In postmenopausal women, a discharge which is unexplained requires further investigations.
Concern about vaginal discharge is the reason for many primary care consultations. It is important to establish whether the discharge is physiological or pathological.
A detailed history and examination are often enough to decide whether further investigations are needed or if the patient can be reassured.
With physiological causes, the discharge is usually clear, and is not offensive, itchy or bloodstained. Any change in discharge could be linked to variation with menstrual cycle, an increase during ovulation, sexual arousal, pregnancy or postpartum, or following abortion.
Bacterial vaginosis (BV) and candidiasis are common infective causes of abnormal vaginal discharge.2,3
BV is caused by an overgrowth of anaerobic organisms in the vagina - Gardnerella vaginalis and Mycoplasma hominis. It is not sexually transmitted and future fertility is not affected. BV is one of the most common causes of discharge in women of reproductive age.
Typically, the discharge is thin, profuse and fishy-smelling, not usually associated with itching or irritation. Vaginal pH is ≥4.5.
It can be a remitting and recurring condition associated with multiple sexual partners, black ethnicity, smoking and IUD use.4
In pregnancy, BV may cause spontaneous premature birth and endometritis.5 NICE does not recommend routine screening.6 There are reports of an increased risk of postoperative infections in obstetrics and gynaecology with BV.7
Candidiasis is caused by the yeast infection Candida albicans. This is usually a normal vaginal commensal organism and is found in 10-20% of asymptomatic women.
The discharge in candidiasis is typically thick, white, non-offensive and often described as resembling cottage cheese. It is associated with vulval itching and soreness, and may cause superficial dyspareunia and dysuria. The vulva may be normal or oedematous and inflamed. Vaginal pH is less than 4.5 (normal).
The lifetime risk is about 50-75%.8 Recent broad-spectrum antibiotics, local irritants (soap, bubble bath, lubricants, perfumes and tight underclothes) are the most common contributory factors.
The most common cause of bacterial STI in the UK is Chlamydia trachomatis. Risk factors for STIs include age less than 25 years, lack of consistent condom use, and a new or more than one sexual partner in the past year.
The presence of one STI makes the presence of another more likely. Other causes are Neisseria trachomatis, Trichomonas vaginalis (TV) and herpes simplex.
- Determine when the discharge started to appear.
- Ask about the colour, consistency and whether it has a smell.
- Enquire about associated symptoms, such as itching, bleeding, pain, dyspareunia or raised temperature.
- Enquire about any associated urinary or bowel symptoms.
- Ask about any cyclical variation of the discharge.
- Obtain a detailed sexual history, including any new partners.
- Enquire about the patient's contraceptive history.
- Enquire about the last menstrual period and exclude the possibility of pregnancy.
- Enquire about any history of recent use of antibiotics.
- Ask about any coexisting medical condition, such as diabetes.
Pelvic examination is only indicated if pelvic infection or intrauterine pathology is suspected.
Check the cervix using a speculum and look for any contact bleeding or polyp. Perform a smear if this has not been done (according to guidelines).
A vaginal pH test can distinguish between BV and candidiasis. If the pH is ≥4.5 and there is an odour, the most likely cause is BV. A pH of less than 4.5 suggests candidiasis.
Perform a triple swab (chlamydia, high vaginal swab and endocervical swab). Swabs should be placed in a suitable container and if there is any delay in transport, stored at 4°C.
A vulvovaginal swab is a self-taken lower vaginal swab and is an option for women who decline the offer of an examination. The swab is inserted approximately 2 cm in to the vagina, gently rotated for 10-30 seconds and placed in an appropriate transport medium.
Most vaginal discharges can be treated in primary care. If an STI is suspected, refer to GUM clinic.
Bloodstained discharge, associated with pelvic pain and irregular bleed, needs further investigations.
Arrange urgent referral for postmenopausal women with persistent vaginal discharge, even without vaginal bleeding, to exclude cervical or endometrial cancer or polyps.
Simple advice regarding tight clothing, soaps, bubble baths, perfumes and douches should be given to all patients presenting with discharge. Postmenopausal discharge due to estrogen deficiency can be treated with local estrogen cream or oral estrogen in the form of HRT, provided there are no contraindications.
Treatment of BV
First-line treatment for BV is oral metronidazole 400 mg twice daily for five to seven days; 2 g as a single dose (avoid in pregnancy) is the most cost-effective treatment.
Systemic metronidazole and clindamycin enter breast milk, so it is better to use intravaginal treatment in breastfeeding women. There is no need to treat male sexual partners. Treatment of female sexual partners may help, although there are no data for this.
Women with BV who are pregnant or breastfeeding may use metronidazole 400 mg twice a day for five to seven days or intravaginal therapies. A single immediate dose of metronidazole is not recommended.
Vaginal and oral antifungals are equally effective. Clotrimazole 500 mg pessary and 2% topical cream can achieve cure rates of 80% and is the most cost-effective treatment.
If the patient remains symptomatic, clotrimazole pessary 100 mg for six nights or 200 mg for three nights can be effective.
Clotrimazole 10% vaginal cream with applicator and 2% topical cream can be prescribed to those who are not keen to use a pessary. There is no need for routine screening or treatment of sexual partners.
Alternative treatments are econazole nitrate 150 mg pessary for three nights, or miconazole nitrate 1.2 g ovule or 2% cream with applicators once daily for 10–14 nights.
Fluconazole 150 mg immediately or itraconazole 200 mg twice daily can be used in those who find it difficult to use local vaginal creams or pessaries. Oral treatments may interact with other medication and are contraindicated in pregnancy.
In pregnancy, topical imidazoles can be used, but single dose treatment is less effective. Longer regimens of up to seven days may be required. Oral antifungals should be avoided due to the possibility of teratogenicity.
Some 5% of women will have recurrent vulvovaginal candidiasis. If a patient has four documented episodes with partial resolution between the episodes, treat as per BASHH guidance.
- Dr Sharma and Dr Tandon are GPs in Oldham, Lancashire
- This is an updated version of an article that was first published in October 2013.
- Bacterial vaginosis. 2012. www.bashh.org/documents/4413.pdf
- Candida. www.bashh.org/documents/1798.pdf
- RCGP and BASHH. Sexually transmitted infections in primary care. 2013.
- Jones R. Childhood vulvovaginitis and vaginal discharge in general practice. Fam Pract 1996; 13: 369-72.
- Mitchell H. Vaginal discharge - causes, diagnosis and treatment. BMJ 2004; 328: 1306-8.
- NICE. Clinical Knowledge Summary: bacterial vaginosis. London, NICE, July 2014. Available from: http://cks.nice.org.uk/bacterial-vaginosis#azTab (accessed 11 Aug 2017).
- Wilson J. Managing recurrent bacterial vaginosis. Sex Transm Infect 2004; 80: 8-11.
- Goldenberg RL, Hauth JC, Andrews WW. Intrauterine infection and preterm delivery. N Engl J Med 2000; 342: 1500-7.
- NICE. Antenatal care: routine care for the healthy pregnant woman. CG62. London, NICE, March 2008. Available from: www.nice.org.uk/CG62 (accessed 11 Aug 2017).
- Soper DE. Bacterial vaginosis and postoperative infections. Am J Obstet Gynecol 1993; 169: 467-9.
- Faculty of Family Planning and Reproductive Health Care Clinical Effectiveness Unit. FFPRHC and BASHH Guidance (January 2006). The management of women of reproductive age attending non-genitourinary medicine settings complaining of vaginal discharge. J Fam Plann Reprod Health Care 2006; 32: 33-42.
This is an updated version of an article that was originally published in October 2013.