History Taking · Intermediate · O&G

Abnormal Vaginal Discharge with Characteristic Odour

Practise this PLAB 2 history taking station on Bacterial Vaginosis. 8-minute voice AI simulation with feedback on all 3 marking domains.

Clinical scenario

You are an FY2 doctor in primary care. Mrs June Joyce, a 32-year-old woman, presents with vaginal discharge that has a distinctive fishy smell. She is concerned about this symptom and wants treatment. Please take a focused history and discuss your assessment and management plan.

Background notes: PMH: Nil significant, Two uncomplicated pregnancies (daughter age 6, son age 4)

What this station tests

  • Fishy odour as the BV signature: especially after intercourse or during periods
  • BV is NOT sexually transmitted: critical reassurance for the patient's relationship
  • Metronidazole-alcohol interaction: avoid alcohol during and 48 hours after treatment
  • Distinguishing BV from candida (itching, cottage cheese) and trichomonas (frothy, itching, STI)
  • Contributing factors: douching, perfumed products, antibiotics disrupting normal flora

How to use your 8 minutes

  • 0-1 min — Introduction: Introduce yourself, confirm identity, open question. 'What's brought you in today?'
  • 1-4 min — Systematic History: Presenting complaint detail (SOCRATES for pain, timeline, severity). Systems review. PMH, medications, allergies.
  • 4-6 min — Context and ICE: Social history (smoking, alcohol, occupation, living situation). Family history. Ideas, Concerns, Expectations.
  • 6-7 min — Summary and Plan: Summarise findings back to patient. Share differential/working diagnosis. Outline investigation and management plan.
  • 7-8 min — Closing: Safety netting with specific red flags. Arrange follow-up. Check for questions.

Consultation approach

The opening

Fishy-smelling vaginal discharge is BV until proven otherwise. The candidate must distinguish BV from STI and candida, and explain that BV is NOT sexually transmitted (critical for the patient's relationship). Mrs Joyce is 32, married, with 2 weeks of fishy-smelling discharge. She is embarrassed and worried her husband might think she has an STI. Open with: 'Mrs Joyce, vaginal discharge is something we deal with very commonly. Tell me about what you have noticed.'

Core approach

Classic BV presentation. Thin, grey-white discharge with characteristic fishy odour, especially after intercourse or during periods (alkaline pH releases amines). No itching (distinguishes from candida), no pain. She is otherwise well. This is not an STI: BV is a disruption of normal vaginal flora, not an infection transmitted between partners.

Distinguish from other causes. Candida: thick white 'cottage cheese' discharge with itching and soreness. Trichomonas: frothy yellow-green discharge with itching and dysuria (an STI). Gonorrhoea/chlamydia: purulent discharge, may have dysuria or intermenstrual bleeding. The fishy odour without itching is the BV signature.

Identify contributing factors. Recent antibiotic use? New soap or intimate products? Douching? (Disrupts normal flora.) She may have used a new intimate wash thinking it would help, when it actually contributed to the problem.

Closing and safety netting

Treatment: oral metronidazole 400mg BD for 5 to 7 days (first-line) or intravaginal metronidazole gel. Avoid alcohol during treatment and for 48 hours after (disulfiram-like reaction with metronidazole). Her husband does NOT need treatment (BV is not sexually transmitted).

Prevention: avoid douching and perfumed intimate products. Use plain water or emollient wash. Recurrence is common (approximately 50% within 12 months). If recurrent: longer treatment course or maintenance intravaginal metronidazole. Reassure: 'This is very common, it is not an STI, and it does not reflect on your hygiene.' Safety net: 'If symptoms do not improve within a week, or you develop pain or fever, come back.' Follow-up only if symptoms persist.

How examiners mark this station

Examiners will focus on the thoroughness and structure of your history taking for bacterial vaginosis. Domain 1 (Data Gathering) carries the most weight: expect marks for systematic coverage of presenting complaint, red flags, PMH, medications, social and family history. Domain 2 (Clinical Management) requires a clear differential, appropriate investigations, and a safe management plan with safety netting. Domain 3 (Interpersonal Skills) is assessed throughout: genuine exploration of ICE, active listening, empathic responses, and clear communication without jargon.

Domain 1 (Primary focus)

Scores well: BV pattern identified (fishy, thin, no itch). Differentials excluded. Contributing factors explored. Relationship context understood.

Costs marks: Not distinguishing from STI. Not asking about products.

Domain 2 (Primary focus)

Scores well: Metronidazole prescribed. Alcohol warning given. Partner does NOT need treatment. Prevention advice. Recurrence warning.

Costs marks: Treating partner. No alcohol warning. No recurrence information.

Domain 3 (Primary focus)

Scores well: Reassuring it is not an STI. Addressing embarrassment. Not implying hygiene issue. Normalising BV as very common.

Costs marks: Implying STI. Making her feel unclean. Being clinical without empathy.

Common examiner feedback (and how to fix it)

Did not gather sufficient information to make an adequate assessment of the patient's condition

Fix: Use a consistent framework for every history. After covering the presenting complaint, systematically move through PMH, drug history, social history, family history, and ICE. Keep a mental checklist.

Did not identify the patient's problems and/or did not develop a management plan adequately

Fix: Reserve the final 2 minutes to summarise your findings, share your working diagnosis with the patient, and outline your investigation and management plan including safety netting.

Common mistakes in this station

  1. Treating BV as an STI: suggesting partner treatment causes unnecessary relationship strain
  2. Not warning about the metronidazole-alcohol interaction: a significant and commonly missed counselling point
  3. Not addressing recurrence: 50% recurrence within 12 months, patient needs to know this is expected

Resitting PLAB 2?

If you have previously struggled with history taking stations, focus on building a consistent systematic framework that you apply to every case. Practise structuring your history into clear phases (presenting complaint, systems review, PMH, social, ICE) so that even under pressure, you cover all domains. Many resitters lose marks not on knowledge but on organisation and time management.

Example opening

Good morning/afternoon, my name is Dr [Name], I'm one of the doctors here today. Could I confirm your name and date of birth please? Thank you. So, what's brought you in to see me today?

Frequently asked questions

How should I structure the bacterial vaginosis history in this PLAB 2 station?

Fishy-smelling vaginal discharge is BV until proven otherwise. The candidate must distinguish BV from STI and candida, and explain that BV is NOT sexually transmitted (critical for the patient's relationship). Mrs Joyce is 32, married, with 2 weeks of fishy-smelling discharge.

What are examiners marking in this bacterial vaginosis station?

Marks are won for: BV pattern identified (fishy, thin, no itch). Differentials excluded. Contributing factors explored. Relationship context understood. Marks are lost for: Not distinguishing from STI. Not asking about products.

What is the most common mistake candidates make in this bacterial vaginosis station?

Treating BV as an STI: suggesting partner treatment causes unnecessary relationship strain. Another frequent error: Not warning about the metronidazole-alcohol interaction: a significant and commonly missed counselling point.

How do I prepare for this station if I have not managed bacterial vaginosis in clinical practice?

This station rewards process over personal experience. The skill being assessed: BV is NOT sexually transmitted: critical reassurance for the patient's relationship. The written guidance on this page covers the full approach, and practising the consultation aloud builds the fluency the examiner is listening for.

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