Paeds Cases · allergy-and-immunology
The child with a delayed triad after an antibiotic — structured encounter
A structured clinical encounter testing the approach to a serum-sickness-like reaction: eliciting the latency, confirming the triad, excluding the dangerous drug-reaction mimics, applying stepwise symptomatic management, and building an individualised, challenge-informed avoidance decision rather than a blanket lifelong label.
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Target exams
Setting and candidate instructions
You are the paediatric registrar in the emergency department. A four-year-old boy is brought by his parents with a four-day history of a blotchy, moving rash over his trunk and limbs, low-grade fever and stiff, swollen knees. He finished a five-day course of cefaclor for an ear infection eight days ago. He looks miserable but not toxic, with normal observations, no mucosal involvement and no breathing difficulty. The examiner will ask you to build the diagnosis, exclude the dangerous mimics, choose and justify the investigations, construct the stepwise management plan, and make a defensible avoidance decision.
[8] [13]You have read the opening of this case. The complete unit — every section and its primary-source references — is part of the Paediatrics Fellowship fellowship atlas.
References6Show ledgerHide ledger
- [1]Norton AE Serum Sickness-Like Reactions in Children-Is Lifelong Avoidance Indicated? Journal of Allergy and Clinical Immunology: In Practice, 2025.PMID 39978544
- [2]Khalaf R Serum Sickness-Like Reactions Clinical Characteristics and Management: A Systematic Review. Journal of Allergy and Clinical Immunology: In Practice, 2025.PMID 40032232
- [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
- [8]Hebert AA Serum sickness-like reactions from cefaclor in children. Journal of the American Academy of Dermatology, 1991.PMID 1802903
- [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