MBBS OSCE · Dermatology / Rheumatology / Nephrology

OSCE — cutaneous purpura with multi-organ clues: classify and manage ANCA-associated vasculitis

An 8-minute OSCE station distinguishing GPA, MPA and EGPA, linking ANCA patterns (PR3/c-ANCA vs MPO/p-ANCA), recognising renal-pulmonary and cardiac red flags, and outlining induction immunosuppression with infection screening.

8 min stationVerification in progress
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Exam tags

NEET-PGINICETUSMLEPLABMRCP

Brief (to candidate)

A 52-year-old presents with palpable purpura, chronic sinus crusting with epistaxis, haemoptysis, and rising creatinine with active urinary sediment. PR3-ANCA is positive. A second card describes late-onset asthma, marked eosinophilia and mononeuritis multiplex. You have 8 minutes to classify AAV (GPA/MPA/EGPA), prioritise organ-threatening work-up, and outline induction therapy principles.

Candidate instructions

  1. Differentiate GPA, MPA, EGPA clinically.
  2. Map PR3/c-ANCA vs MPO/p-ANCA associations.
  3. Identify renal, pulmonary, cardiac, neurologic red flags.
  4. List urgent investigations including biopsy strategy.
  5. Outline induction/remission principles (steroids + RTX/CYC) and infection risk.

Examiner checklist (mark each domain / 10)

DomainKey actions expected
ClassificationGPA: granulomatous ENT (sinus, saddle nose, otitis) + lung + kidney; often PR3/c-ANCA. MPA: non-granulomatous small-vessel disease, renal ± pulmonary capillaritis/neuropathy; often MPO/p-ANCA. EGPA: late asthma + eosinophilia + neuropathy ± skin; ANCA (often MPO) in a subset; cardiac involvement major mortality driver[1][2][5]
Cutaneous signsPalpable purpura, livedo, nodules, digital ischaemia — skin is a clue, not the whole disease
Organ threatRPGN, DAH/haemoptysis, mononeuritis multiplex, cardiac involvement, vision-threatening scleritis — treat as emergency
Work-upANCA (PR3/MPO), urinalysis/creatinine, CXR/CT chest, ENT assessment, eosinophil count, troponin/echo if EGPA suspicion; tissue biopsy (kidney/skin/lung/nerve) as safe and informative
InductionHigh-dose glucocorticoids + rituximab or cyclophosphamide for organ-threatening disease; plasma exchange considered in selected severe presentations per evolving evidence/guidelines; PCP and infection prophylaxis planning[3]
MaintenanceRemission maintenance (e.g. rituximab/azathioprine strategies), relapse surveillance, long-term steroid minimisation
SafetyScreen/treat infection before heavy immunosuppression when possible; vaccinate appropriately; multidisciplinary care (rheum/nephrology/ENT/pulm)

Model key actions

  • Classify GPA vs MPA vs EGPA using ENT granulomatous features, eosinophilic asthma, and ANCA subtype.[1][2]
  • Escalate immediately for RPGN/DAH; plan biopsy + induction immunosuppression per EULAR-style care.[3]
  • In EGPA, specifically assess heart disease risk.[5]

Common errors

  • Treating skin-limited thinking without urine/chest assessment.
  • Conflating all AAV as one phenotype.
  • Missing EGPA cardiac risk.
  • Delaying induction while awaiting non-essential tests in organ-threatening disease.
  • Forgetting infection prophylaxis with intense immunosuppression.
References4Show
  1. [1]Kronbichler A, Bajema IM, Bruchfeld A, et al. Diagnosis and management of ANCA-associated vasculitis. Lancet, 2024.PMID 38368016
  2. [2]Kitching AR, Anders HJ, Basu N, et al. ANCA-associated vasculitis. Nature Reviews Disease Primers, 2020.PMID 32855422
  3. [3]Hellmich B, Sanchez-Alamo B, Schirmer JH, et al. EULAR recommendations for the management of ANCA-associated vasculitis: 2022 update. Annals of the rheumatic diseases, 2024.PMID 36927642
  4. [5]White J, Dubey S. Eosinophilic granulomatosis with polyangiitis: A review. Autoimmunity reviews, 2023.PMID 36283646
OSCE — cutaneous purpura with multi-organ clues: classify and manage ANCA-associated vasculitis · MBBS OSCE · NeetVellum