Immediate perioperative hypersensitivity (POH) reactions are rare but potentially life-threatening. Although well described in adults, data are scarce in children.

The aim of this study was to describe the main characteristics of paediatric POH reactions, comparing whether the causal agent was identified or not.

This study was a retrospective multicenter study analysing data from the French Groupe d’étude des réactions anaphylactiques peropératoires (GERAP). Children (< 18 y) who experienced a POH reaction and had been investigated in one of the GERAP centres wereincluded. Raw data from 5 previously published surveys (1997–2012) and the GERAP database (2017–2024) were analysed. The main characteristics were medical history, clinical manifestations, anaesthetic management, and allergy workup.

Among 4,605 POH reactions included in the GERAP database, 461 cases of paediatric POH were recorded. The median age was 14 y [range: 10–16], and 47% were girls. Most reactions occurred during general anaesthesia (91%) including 66% during induction. Fifty percent of reactions were grade I reactions but 23% were grade II, 26% grade III and 1% grade IV. In 44% of cases, a causal agent was identified, mainly neuromuscular-locking agents [NMBA] (30%) and latex (29%). The distribution of causal agents changed significantly over time. The prevalence of latex-related reactions significantly decreased, while NMBA and antibiotics became predominant. POH reactions with identification of the causal agent and a proven IgE-mediated mechanism were more severe (grade III-IV) compared to reactions without any identification (45% vs. 12%, P < 0.001).

Based on the largest cohort of paediatric POH reactions to date, we found that paediatric POH are not uncommon and can be life-threatening. Greater severity was observed in children with an identified IgE-mediated mechanism and when a causal agent was identified. While current preventive measures appear to be effective in reducing the risk of latex-related POH reactions, NMBA and antibiotics now represent the main triggers in this population.