Vaginal Discharge & Vaginitis

The approach to vaginal discharge, and the two commonest non-STI causes — bacterial vaginosis and vulvovaginal candidiasis. The STI causes (chlamydia, gonorrhoea, trichomoniasis) have their own pages; see also STIs (screening & overview).

Physiological discharge

From cervical mucus, vaginal transudate, desquamated squamous/columnar cells and commensal flora. Lactobacilli keep the vaginal pH acidic (<4.7). Normal discharge has no odour or pruritus and varies across the cycle.

Examination

• Inspect the vulva (erythema, excoriation, lichenification, fissures, atrophy).
• Examine the discharge itself.
• Speculum: mucopurulent cervical discharge suggests chlamydia/gonorrhoea; look for fistula, prolapse, polyp, warts.
• Bimanual for adnexal/uterine/cervical-motion tenderness if PID is possible.

Investigations

• High vaginal swab for M/C/S (candida species, Gardnerella).
• High vaginal / cervical swab PCR for chlamydia, gonorrhoea, trichomonas.
• pH of the discharge (narrow-range 4–7 paper).
• Whiff test (10% KOH → fishy odour = BV).
• Wet-film microscopy (clue cells, hyphae, motile trichomonads).

Bacterial vaginosis

A polymicrobial syndrome — loss of hydrogen-peroxide-producing lactobacilli and overgrowth of anaerobes/fastidious bacteria (e.g. Gardnerella vaginalis). Not an STI.

Amsel criteria — 3 of 4 needed:

• Thin, white, homogeneous discharge
• Vaginal pH >4.5
• Clue cells on wet prep/gram stain (epithelial cells studded with coccobacilli)
• Positive whiff test (fishy odour on adding 10% KOH)

Management (symptomatic women — odour, dyspareunia, dysuria, pruritus):

• Metronidazole 400 mg orally BD for 7 days, or
• Metronidazole 0.75% vaginal gel nightly for 5 nights.

Male partners are not treated; assess female partners. (Some evidence for treating male partners in recurrent BV.)

Vulvovaginal candidiasis

Common in women aged 20–30 and in pregnancy. Recurrent = ≥4 acute episodes/year.

Features: intense vulvovaginal pruritus, soreness, fissures, erythema, oedema, excoriation; thick white curd-like discharge; superficial dyspareunia, dysuria.

Predisposing factors: endogenous (diabetes, pregnancy, immunodeficiency/HIV); exogenous (COC, HRT/topical oestrogen, antibiotics, corticosteroids, immunosuppressants, IUCD, occlusive/synthetic clothing, wet swimwear).

Investigation: vaginal swab for M/C/S to confirm and speciate (guides recurrent/ resistant cases).

Management (C. albicans):

• Clotrimazole pessary — 100 mg for 6 nights, or 200 mg for 3 nights, or 500 mg single dose; or 2% cream for 3 nights.
• Fluconazole 150 mg orally single dose if oral preferred and not pregnant.

Non-albicans (C. glabrata): boric acid 600 mg pessary nightly for 14 days.

Chronic/recurrent candidal vulvovaginitis: chronic itch ± dyspareunia, often no discharge, worse premenstrually; ~95% C. albicans; considered an irritant dermatitis reaction to Candida (swabs may be negative). Fluconazole 50 mg daily (nystatin pessary if pregnant); remission takes 2 weeks–6 months (review at 3 months), then maintain with interval therapy (same dose, less often — e.g. once or twice weekly), titrated to response; long-term treatment is often needed.