History Taking · Foundation · Dermatology

Itchy Red Patches on Elbows and Knees

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

Clinical scenario

You are an FY2 doctor in a GP surgery. Mrs Rita Bailey, a 45-year-old woman, has come to see you with red, scaly patches on her elbows and knees that have been present for several months. She is concerned about the appearance and the itching is affecting her quality of life. Please take a focused history and discuss management options with the patient.

Background notes: PMH: Good health, occasional tension headaches

What this station tests

  • Classic plaque psoriasis features: well-demarcated erythematous plaques with silvery scale on extensor surfaces
  • Screening for psoriatic arthropathy: DIP joint involvement, dactylitis, asymmetric oligoarthritis
  • Screening for nail changes: pitting and onycholysis support the diagnosis and indicate disease activity
  • Combined vitamin D analogue and corticosteroid as first-line topical treatment
  • Assessing psychological impact: DLQI, body image concerns, social avoidance

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

Psoriasis stations test the candidate's ability to diagnose a chronic skin condition, assess for associated conditions (psoriatic arthropathy, metabolic syndrome, depression), and provide a management plan. Mrs Bailey is 45, presenting with 8 months of red, scaly patches on elbows and knees. She is worried about appearance as summer approaches. Open with: 'Mrs Bailey, tell me about these patches and how they are affecting you.'

Core approach

Classic plaque psoriasis presentation. Well-demarcated, raised, erythematous plaques with silvery-white scale on extensor surfaces (elbows, knees). Bilateral and symmetrical. Itchy, especially in evenings and when stressed. Present for 8 months, gradually worsening. Her maternal grandfather had severe psoriasis (genetic predisposition). She has tried OTC moisturisers without improvement.

Screen for associated conditions. Psoriatic arthropathy: any joint pain or stiffness? (Typically DIP joints, asymmetric, dactylitis.) Nail changes: pitting, onycholysis, subungual hyperkeratosis? Scalp involvement: any scale in hair? Inverse psoriasis: any rash in skin folds? Screen for metabolic syndrome: BMI, waist circumference, BP (she has normal BP). Screen for mood: psoriasis significantly affects mental health.

Assess severity. Less than 10% BSA = mild. Her elbows and knees represent approximately 3 to 5% BSA (mild to moderate). However, the DLQI (Dermatology Life Quality Index) may be disproportionately high if it affects her confidence and social life. Summer clothing anxiety is a real functional impact.

Closing and safety netting

First-line for mild plaque psoriasis: potent topical corticosteroid (betamethasone dipropionate) combined with vitamin D analogue (calcipotriol). Available as a combined preparation (Dovobet/Enstilar). Apply once daily for 4 weeks initially. Emollients as adjunct (reduce scale, improve comfort). Coal tar preparations for maintenance. If topical treatment fails: refer to dermatology for phototherapy or systemic treatment (methotrexate, ciclosporin, biologics for severe disease).

Explain the chronic nature: 'Psoriasis is a long-term condition that tends to come and go. We cannot cure it, but we can control it very effectively. Most people with mild psoriasis manage well with creams.' Address her summer concern: with treatment, significant improvement is expected within 4 to 6 weeks. Safety net: 'If the patches spread significantly, your joints become painful or swollen, or the treatment is not working, come back.' Follow-up in 6 weeks.

How examiners mark this station

Examiners will focus on the thoroughness and structure of your history taking for psoriasis. 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: Data Gathering, Technical and Assessment Skills (Primary focus)

Scores well: Classic features identified. Severity assessed (BSA). Joints screened. Nails checked. Scalp and flexures asked. Family history. Triggers (stress). Psychological impact assessed.

Costs marks: Not screening joints. Not checking nails. Not assessing severity. Not asking about psychological impact.

Domain 2: Clinical Management Skills (Primary focus)

Scores well: Correct first-line topical treatment (combined corticosteroid/vitamin D). Emollients as adjunct. Time-limited steroid course. Referral pathway for non-responders. Follow-up at 6 weeks.

Costs marks: Wrong topical treatment. No time limit on steroids. No referral pathway. No follow-up.

Domain 3: Interpersonal Skills (Throughout)

Scores well: Addressing summer clothing anxiety. Explaining chronic nature honestly but with hope. Providing realistic treatment timeline. Acknowledging psychosocial impact.

Costs marks: Dismissing appearance concern. Not explaining chronicity. Being pessimistic about treatment.

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. Not screening for psoriatic arthropathy. Up to 30% of psoriasis patients develop joint disease. Candidates who treat the skin without asking about joints miss an associated condition.
  2. Not checking nails. Nail changes (pitting, onycholysis) are present in up to 50% of psoriasis patients and support the diagnosis. Candidates who do not examine or ask about nails miss supportive evidence.
  3. Using very potent steroids without time limits. Topical corticosteroids on body sites should be used for defined periods (4 weeks initially) with review. Candidates who prescribe indefinitely risk steroid side effects.

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

What is the best way to take a psoriasis history in PLAB 2?

Psoriasis stations test the candidate's ability to diagnose a chronic skin condition, assess for associated conditions (psoriatic arthropathy, metabolic syndrome, depression), and provide a management plan. Mrs Bailey is 45, presenting with 8 months of red, scaly patches on elbows and knees. She is worried about appearance as summer approaches.

Where are marks won and lost in this psoriasis station?

Examiners reward: Classic features identified. Severity assessed (BSA). Joints screened. Nails checked. Scalp and flexures asked. Family history. Triggers (stress). Candidates are penalised for: Not screening joints. Not checking nails. Not assessing severity. Not asking about psychological impact.

Where do candidates most often go wrong in this station?

Not screening for psoriatic arthropathy. Up to 30% of psoriasis patients develop joint disease. Candidates who treat the skin without asking about joints miss an associated condition.

Can I do well in this station without real-world experience of psoriasis?

This station rewards process over personal experience. The skill being assessed: Screening for psoriatic arthropathy: DIP joint involvement, dactylitis, asymmetric oligoarthritis. Work through the consultation approach above, then rehearse it aloud under the 8-minute time pressure so the structure holds up in the exam.

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