Vaginal Discharge & Vulvovaginitis

❍ At a glance

• The key initial distinction is physiological versus pathological, and then whether the aetiology is lower genital tract (vulvovaginal) or upper genital tract (cervicitis, PID). Dyspareunia, abnormal bleeding, and cervical pathology can all initially present as a complaint of discharge - do not attribute all discharge to lower tract causes without considering upper tract pathology.
• BV diagnosis: Amsel criteria (three of four) - thin homogeneous grey-white discharge; pH greater than 4.5; fishy odour on KOH whiff test; clue cells on wet preparation. Treatment: metronidazole 400 mg twice daily for 7 days has the highest cure rates.¹ Male partners do not require treatment.
• VVC: itch is the dominant symptom; pH is normal (below 4.5) - this distinguishes it from BV. Fluconazole 150 mg stat is first-line. Four or more episodes per year warrants HbA1c, FBC, HIV, culture and sensitivity (to exclude non-albicans Candida resistant to fluconazole).
• Avoid over-investigation of physiological discharge. Excessive hygiene practices disrupt lactobacillus flora and increase BV risk - explain this to patients presenting with recurrent symptoms.

❍ Conditions and management

Physiological discharge: clear to white, non-offensive, varies with the menstrual cycle, increases at ovulation and in pregnancy. No itch, odour, burning, or dyspareunia. Reassure and explain the physiological cycle. Excessive internal washing and scented products disrupt vaginal flora - discourage these practices.

Bacterial vaginosis (BV): the most common cause of abnormal discharge - polymicrobial overgrowth replacing normal lactobacillus-dominant flora. Thin, grey-white discharge with fishy odour (worse after unprotected sex or during menstruation). No significant itch (itch suggests candidiasis). Diagnosis by Amsel criteria (three of four).¹ Treatment: metronidazole 400 mg twice daily for 7 days (highest cure rate); alternatives include intravaginal metronidazole gel or clindamycin cream. BV recurs in up to 50% within 12 months - maintenance intravaginal metronidazole gel (twice weekly) for recurrent BV. Safe to treat in pregnancy (associated with preterm birth). Male partners do not require treatment.

Vulvovaginal candidiasis (VVC): itch is the dominant symptom. Thick, curdy white discharge, vulval soreness, dyspareunia, dysuria. Vaginal pH normal (below 4.5). Treatment: fluconazole 150 mg stat (first-line, funded); topical clotrimazole as alternative (preferred in pregnancy - avoid fluconazole in first trimester). Recurrent VVC (4+ episodes/year): investigate (HbA1c, FBC, HIV, culture and sensitivity). Non-albicans Candida (C. glabrata, C. krusei) is resistant to fluconazole and requires specialist guidance. Maintenance fluconazole 150 mg weekly for 6 months reduces recurrence significantly.²

Trichomoniasis: STI (Trichomonas vaginalis). Frothy, green-yellow, malodorous discharge; itch, soreness, elevated pH. NAAT on vaginal swab is most sensitive. Treatment: metronidazole 400 mg twice daily for 7 days; both partners simultaneously. Notifiable in NZ.

Atrophic vaginitis: postmenopausal women; thin, watery, or blood-tinged discharge with dyspareunia, itch, recurrent UTI. Elevated pH. Treatment: topical vaginal oestrogen (see Menopause page).

When to consider cervicitis or PID: discharge with cervical motion tenderness, pelvic pain, IMB/PCB, systemic features, or STI risk factors requires NAAT for chlamydia and gonorrhoea and assessment for upper tract infection.

❍ Referral criteria

Most vulvovaginal conditions are managed in primary care. Refer to sexual health or gynaecology for: recurrent VVC not responding to standard maintenance therapy; non-albicans candidiasis confirmed on culture; persistent symptoms after adequate treatment; STI with resistant organisms; or symptoms where examination is difficult or uncertain.