Derm Cases · Dermatology / General Medicine
OSCE — assessment of chronic plaque psoriasis with suspected psoriatic arthritis
An 8-minute OSCE station assessing the candidate's recognition of plaque psoriasis, examination of the skin/nails/joints, severity grading with PASI, comorbidity screening and stepwise management — including correct avoidance of systemic corticosteroids.
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Study tools
Target exams
NEET-PGINICETUSMLEPLAB
Prompt
An 8-minute OSCE station assessing the candidate's recognition of plaque psoriasis, examination of the skin/nails/joints, severity grading with PASI, comorbidity screening and stepwise management — including correct avoidance of systemic corticosteroids.
Brief (to candidate)
A 38-year-old man has extensive well-demarcated erythematous plaques with silvery scale on the elbows, knees, scalp and lower back (~15% body-surface area), nail pitting with onycholysis, and a swollen painful right middle finger with morning stiffness. You have 8 minutes to assess him, grade severity, screen for psoriatic arthritis and comorbidity, and outline stepwise management.
[4]Candidate instructions
- Examine the skin, nails and joints in a structured way; elicit the named signs.
- Grade severity using an appropriate score and state the moderate-to-severe threshold.
- Apply criteria to confirm or exclude psoriatic arthritis.
- Outline comorbidity screening and the stepwise management with drug, dose, monitoring and rationale.
- State your disposition and safety-net advice.
Examiner checklist (mark each domain / 10)
| Domain | Key actions expected |
|---|---|
| Recognition | Identifies well-demarcated erythematous plaque with silvery scale on extensors/scalp as psoriasis; elicits Auspitz sign and names Koebner phenomenon[2] |
| Nail & joint exam | Inspects nails (pitting, onycholysis, oil-drop); examines DIP joints, looks for dactylitis ('sausage digit') and enthesitis; identifies psoriatic arthritis |
| Severity — PASI | Reproduces PASI components (erythema + induration + desquamation 0–4 × area 0–6; range 0–72); states >10–12 = moderate-to-severe[1] |
| CASPAR criteria | Reproduces CASPAR (inflammatory articular disease + ≥3 points: current psoriasis 2, personal/family history 1, nail dystrophy 1, negative RF 1, dactylitis 1, juxta-articular new bone 1)[4] |
| Comorbidity screening | Measures/screens BMI, BP, lipids, glucose, mood, alcohol/smoking; states the 'psoriatic march' / cardiovascular risk |
| Stepwise management | Topical steroid + calcipotriol → narrowband UVB → methotrexate 7.5–25 mg once weekly + folic acid (monitor FBC/LFTs) → biologic; doses and rationale[6] |
| Safety & communication | Avoids systemic corticosteroids (rebound); screens TB/hepatitis before biologic; clear plan and follow-up |
Model key actions
- Recognise the plaque, elicit the Auspitz sign, name the Koebner phenomenon; examine nails and joints.[2]
- Grade with PASI (>10–12 moderate-to-severe) and confirm psoriatic arthritis with CASPAR.[1][4]
- Methotrexate 7.5–25 mg once weekly + folic acid 5 mg weekly, monitor FBC and LFTs; escalate to an anti-IL-17 / anti-IL-23 biologic (TB/hepatitis screen first) if inadequate response.[6]
- Avoid systemic corticosteroids — withdrawal causes pustular/erythrodermic rebound.
- Screen and manage cardiometabolic comorbidity (the psoriatic march).
Common errors
- Missing psoriatic arthritis (not examining the joints/nails).
- Not applying PASI to justify systemic escalation.
- Prescribing systemic corticosteroids (rebound flare).
- Inadequate methotrexate monitoring (FBC/LFTs).
- Neglecting cardiometabolic and depression screening.
References4ShowHide
- [1]Boehncke WH, Schön MP. Psoriasis. Lancet, 2015.PMID 26025581
- [2]Griffiths CEM, Barker JNWN. Pathogenesis and clinical features of psoriasis. Lancet, 2007.PMID 17658397
- [4]Taylor W, et al. Classification criteria for psoriatic arthritis (CASPAR). Arthritis and Rheumatism, 2006.PMID 16871531
- [6]Menter A, et al. Joint AAD-NPF guidelines: systemic nonbiologic therapies. J Am Acad Dermatol, 2020.PMID 32119894