Synopsis
Distinguish the common causes of vaginal discharge by symptoms, examination and point-of-care or laboratory testing, then use diagnosis-specific treatment, pregnancy precautions and partner management.
- Bacterial vaginosis typically causes thin homogeneous grey-white discharge and a fishy odour with little vulval inflammation.
- Vulvovaginal candidiasis usually causes intense itch, soreness, erythema and thick white discharge; vaginal pH generally remains normal.
- Trichomoniasis may cause offensive yellow-green or frothy discharge, vulval irritation and punctate cervical inflammation, but many infections are asymptomatic.
- History and examination guide testing; symptoms alone are insufficient because mixed infection and non-infective vulval disease are common.
- Use vaginal pH, microscopy or validated nucleic-acid testing according to the syndrome and local sexual-health pathway.
- Treat bacterial vaginosis and trichomoniasis with a recommended nitroimidazole regimen, but trichomoniasis also requires partner treatment and sexual abstinence until completion.
- Treat uncomplicated candidiasis with a topical azole or oral fluconazole; in pregnancy use topical azole therapy and avoid oral fluconazole.
- Do not routinely treat asymptomatic bacterial-vaginosis partners or candidiasis partners unless they have symptoms.
Key red flags
Pelvic pain, cervical motion tenderness or adnexal tenderness suggests pelvic inflammatory disease rather than isolated vaginitis.
Fever, hypotension, severe vulval pain, necrosis or rapidly spreading erythema requires emergency assessment for invasive infection.
Pregnancy with pain, bleeding, contractions or reduced fetal movements needs same-day maternity assessment.
Persistent vulval ulceration, bleeding, skin change or a mass requires examination and possible biopsy rather than repeated empirical thrush treatment.
Recurrent candidiasis, severe infection or unusual species should prompt diabetes, immune and microbiological review.
Frothy discharge with urinary symptoms, exposure risk or a new partner warrants testing for trichomonas and other STIs.
Deep dyspareunia, intermenstrual bleeding, pelvic pain, fever or cervical excitation requires assessment for PID.
Investigation priorities
Differentiate normal-pH candidiasis from pH elevation in bacterial vaginosis or trichomoniasis.
Management branches
A patient presents with new vaginal discharge, odour, itch or vulval soreness.
- Ask onset, discharge, odour, itch, pain, bleeding, urinary symptoms, pregnancy possibility, antibiotics, diabetes, products and sexual exposures.
- Examine vulva and use speculum assessment when clinically appropriate, checking cervix, retained foreign body, ulcers and upper-tract tenderness.
- Perform pH and microscopy or send vaginal NAAT and culture according to local capability and recurrence status.
- Offer site-appropriate STI testing and HIV or syphilis screening according to exposure rather than assuming all discharge is candidiasis.