Derm Cases · Dermatology / Allergy & Immunology / Emergency Medicine
OSCE — chronic spontaneous urticaria vs bradykinin angioedema
An 8-minute OSCE station on acute vs chronic urticaria thresholds, inducible forms, EAACI stepwise antihistamine/omalizumab pathway, and red-flag distinction of mast-cell vs bradykinin-mediated angioedema.
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Study tools
Target exams
NEET-PGINICETUSMLEPLABMRCP
Prompt
An 8-minute OSCE station on acute vs chronic urticaria thresholds, inducible forms, EAACI stepwise antihistamine/omalizumab pathway, and red-flag distinction of mast-cell vs bradykinin-mediated angioedema.
Brief (to candidate)
A 34-year-old woman has daily itchy wheals for 4 months, each lesion lasting under 24 hours, with occasional lip swelling without stridor. Antihistamine once daily helps only partially. There is no food trigger and no family history of HAE. You have 8 minutes to classify disease, exclude dangerous angioedema phenotypes, score activity, and escalate therapy per guideline.
[5]Candidate instructions
- Define acute vs chronic urticaria and CSU vs inducible.
- Characterise wheals vs angioedema and red flags for anaphylaxis / bradykinin angioedema.
- Avoid unnecessary extensive allergy testing when history is spontaneous.
- Use UAS7 / UCT concepts and the EAACI step ladder.
- Counsel on omalizumab step and emergency care for airway angioedema.
- Safety-net NSAID/ACE-inhibitor drug issues.
Examiner checklist (mark each domain / 10)
| Domain | Key actions expected |
|---|---|
| Classification | Symptoms ≥6 weeks = chronic; spontaneous daily wheals = CSU; distinguishes inducible forms (dermographism, cold, cholinergic, delayed pressure)[1][3] |
| Lesion biology | Wheals fleeting (<24 h), itchy; angioedema deeper, slower; mast-cell/histamine pathway for typical CSU[2] |
| Dangerous phenotypes | Airway compromise / anaphylaxis pathway; ACE-inhibitor angioedema and HAE (no wheals, abdominal attacks, family history, poor antihistamine/adrenaline response) — different treatment |
| Work-up restraint | Focused history/exam; limited bloods (e.g. CBC, CRP) rather than shotgun IgE panels if spontaneous; provocation only for suspected inducible disease |
| Stepwise Rx | Second-generation H1-antihistamine standard dose → up-dose up to 4× → add omalizumab for antihistamine-refractory CSU; short corticosteroid burst only for severe flares, not chronic control[3][2] |
| Scores & QoL | Mentions UAS7 activity and UCT control to guide step-up; addresses sleep and work impact |
| Communication | Avoids chronic oral steroids; review NSAIDs/ACEI; emergency advice if tongue/throat swelling; specialist referral for refractory disease |
Model key actions
- Diagnose chronic spontaneous urticaria (4 months of daily fleeting wheals).[1][2]
- Escalate per EAACI: non-sedating H1AH up-dosing → omalizumab if refractory; not chronic prednisolone.[3]
- Separate bradykinin angioedema phenotypes that will not respond to antihistamines/omalizumab.
Common errors
- Labelling as food allergy without supportive history and ordering extensive unnecessary tests.
- Long-term systemic corticosteroids for CSU.
- Failing to up-dose antihistamines before declaring failure.
- Missing ACE-inhibitor / HAE angioedema without wheals.
- No airway safety-net advice for oropharyngeal swelling.
References5ShowHide
- [1]Kolkhir P, Giménez-Arnau AM, Kulthanan K, et al. Urticaria. Nature Reviews Disease Primers, 2022.PMID 36109590
- [2]Kolkhir P, Bonnekoh H, Metz M, et al. Chronic Spontaneous Urticaria: A Review. JAMA, 2024.PMID 39325444
- [3]Zuberbier T, Abdul Latiff AH, Abuzakouk M, et al. The international EAACI/GA²LEN/EuroGuiDerm/APAAACI guideline for the definition, classification, diagnosis, and management of urticaria. Allergy, 2022.PMID 34536239
- [4]Kolkhir P, Muñoz M, Asero R, et al. Autoimmune chronic spontaneous urticaria. Journal of Allergy and Clinical Immunology, 2022.PMID 35667749
- [5]Young MC, Banerji A. Angioedema without urticaria: Diagnosis and management Allergy Asthma Proc, 2025.PMID 40380367