Obstetrics and Gynaecology
Vaginal Discharge and Genital Infections
Bacterial vaginosis, candidiasis, trichomoniasis, STIs and pelvic inflammatory disease for MBBS, with diagnosis and treatment, mapped to NMC codes OG22 and OG27.
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Vaginal Discharge and Genital Infections
Bacterial vaginosis, candidiasis, trichomoniasis, STIs and pelvic inflammatory disease for MBBS, with diagnosis and treatment, mapped to NMC codes OG22 and OG27.
This chapter provides a practical approach to vaginal discharge and genital infections. It distinguishes physiological discharge from bacterial vaginosis, candidiasis and trichomoniasis by their clinical features, pH and microscopy, and covers sexually transmitted infections, pelvic inflammatory disease and the principles of syndromic management and partner treatment.
High-yield: Vaginal Discharge and Genital Infections
- Physiological vaginal discharge is clear or white, non-offensive and varies with the menstrual cycle.
- Bacterial vaginosis gives a thin grey homogeneous discharge with a fishy odour and clue cells on microscopy.
- The whiff test with potassium hydroxide releases a fishy amine odour in bacterial vaginosis.
- Bacterial vaginosis is diagnosed by Amsel criteria and treated with metronidazole.
- Vulvovaginal candidiasis causes intense itching with a thick, white, curd-like discharge and is treated with azole antifungals.
- Trichomoniasis gives a frothy, greenish, offensive discharge with a strawberry cervix and motile trichomonads on wet mount.
- Trichomoniasis is a sexually transmitted infection and both partners are treated with metronidazole.
- Vaginal pH is raised above 4.5 in bacterial vaginosis and trichomoniasis but normal in candidiasis.
- Pelvic inflammatory disease is ascending infection causing lower abdominal pain, fever, discharge and cervical motion tenderness.
- Chlamydia and gonorrhoea are the main causes of pelvic inflammatory disease and often coexist.
- Untreated pelvic inflammatory disease can lead to infertility, ectopic pregnancy and chronic pelvic pain.
- Syndromic management of sexually transmitted infections treats likely pathogens without waiting for laboratory confirmation.
- Partner notification and treatment are essential to prevent reinfection in sexually transmitted infections.
- Genital ulcers may be caused by herpes simplex, syphilis (painless chancre) or chancroid (painful ulcer).
Common causes of vaginal discharge
- **Bacterial vaginosis:** Thin grey fishy discharge, clue cells, pH above 4.5. Metronidazole.
- **Candidiasis:** Thick white curd-like discharge, intense itch, normal pH. Azoles.
- **Trichomoniasis:** Frothy green offensive discharge, strawberry cervix, pH above 4.5. Metronidazole, treat partner.
- **Pelvic inflammatory disease:** Pain, fever, cervical motion tenderness; chlamydia and gonorrhoea.
NMC competencies in this chapter
- **OG22.1:** Approach to vaginal discharge
- **OG22.2:** Investigations for vaginal discharge and genital infection
- **OG27.1:** Bacterial vaginosis
- **OG27.2:** Vulvovaginal candidiasis
- **OG27.3:** Trichomoniasis
- **OG27.4:** Sexually transmitted infections and pelvic inflammatory disease
Frequently Asked Questions
How do you distinguish the common causes of vaginal discharge?
Bacterial vaginosis gives a thin grey fishy discharge with clue cells, candidiasis a thick white itchy discharge, and trichomoniasis a frothy green discharge with a strawberry cervix. Vaginal pH and microscopy help confirm.
What is the whiff test?
Adding potassium hydroxide to the discharge releases a fishy amine odour in bacterial vaginosis and trichomoniasis, one of the Amsel criteria for bacterial vaginosis.
Why is pelvic inflammatory disease important?
It is usually due to chlamydia or gonorrhoea and, if untreated, can cause infertility, ectopic pregnancy and chronic pelvic pain, so it needs prompt treatment.
What is syndromic management?
Treating the likely pathogens of a sexually transmitted infection based on the clinical syndrome without waiting for laboratory results, along with partner treatment to prevent reinfection.
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