Paeds Vivas · allergy-and-immunology
Serum sickness and serum-sickness-like reactions — branching viva
A branching viva following the serum-sickness picture across the clinical spectrum, from a cefaclor SSLR in a young child, through the differentiation from a viral exanthem and the dangerous drug-reaction mimics, to true immune-complex serum sickness after rituximab, and finally to the avoidance and re-challenge decision, with the complement mechanism and the evidence boundaries tested throughout.
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Study tools
Target exams
RACP General PaediatricsRACP DCERCPCH Progress+MRCPCH ClinicalABP General PediatricsACGME PediatricsRCPSC Pediatrics
Prompt
The examiner releases the topic in stages, beginning with a four-year-old with rash, fever and stiff knees eight days after a cefaclor course, moving to the distinction between a true SSLR and a viral confounder, then to the dangerous mimics (anaphylaxis, SJS/TEN, DRESS), and finally to a teenager with true serum sickness ten days after rituximab for an autoimmune disease. The candidate must state the mechanism before the action, justify the complement split, and build a defensible avoidance decision at each stage.
Viva format
The examiner takes the candidate through four escalating branches, each anchored to a patient. At each stage the candidate must state the reasoning before the action, name the mechanism, and respect the true-serum-sickness versus SSLR split. The examiner probes the why and the corners. [5]
References7ShowHide
- [1]Norton AE Serum Sickness-Like Reactions in Children-Is Lifelong Avoidance Indicated? Journal of Allergy and Clinical Immunology: In Practice, 2025.PMID 39978544
- [3]Delli Colli L Differentiating Between β-Lactam-Induced Serum Sickness-Like Reactions and Viral Exanthem in Children Using a Graded Oral Challenge. Journal of Allergy and Clinical Immunology: In Practice, 2021.PMID 32898711
- [5]Lawley TJ A prospective clinical and immunologic analysis of patients with serum sickness. New England Journal of Medicine, 1984.PMID 6387492
- [8]Hebert AA Serum sickness-like reactions from cefaclor in children. Journal of the American Academy of Dermatology, 1991.PMID 1802903
- [11]Bayer G Rituximab-induced serum sickness is more frequent in autoimmune diseases as compared to hematological malignancies: A French nationwide study. European Journal of Internal Medicine, 2019.PMID 31279430
- [12]Pichler WJ Immune pathomechanism and classification of drug hypersensitivity. Allergy, 2019.PMID 30843233
- [13]Robson M Updates in Pediatric Drug Allergy. Current Allergy and Asthma Reports, 2026.PMID 41706240