D2.324 - Anaphylaxis in very early childhood: An ongoing challenge

Anaphylaxis is a serious, rapid-onset allergic reaction that requires timely recognition and immediate treatment with adrenaline. The prevalence of anaphylaxis is rising globally, with particularly marked increases reported in very young children. Despite this trend, current standard definitions of anaphylaxis do not include symptoms specific to infants and toddlers, and a global paucity of data specifically describing these phenotypes remains. This study aimed to improve characterisation of clinical phenotypes and management of infant and toddler anaphylaxis, to inform age-specific care pathways and guideline development.

We identified children aged 0-2 years who presented with anaphylaxis to the sole tertiary Paediatric Emergency Department (PED) in the state of Western Australia over a ten-year period (2003 to 2007 and 2013 to 2017). Collected data included vital signs, features of anaphylaxis, suspected allergens, management, and prescription of an adrenaline autoinjector (AAI).

Children aged 0-2 years with anaphylaxis accounted for 72 cases out of 236217 total presentations in 2003-2007, and 171 out of 331,378 in 2013-2017. Mucocutaneous symptoms were observed in 95.8% (229/239) of cases, respiratory in 81.6% (195/239), gastrointestinal in 43.1% (103/239), neurological in 18.8% (45/239), and cardiovascular in 33.9% (81/239). BP was recorded in 154 cases, with hypotension identified in four cases (2.6%). Further descriptors reported by clinicians included shallow breathing, choking, grunting, gagging, gasping, throat clearing, drooling and dysphagia. Food-related anaphylaxis was found in 94.6%. In 147/243 cases, symptoms had resolved on arrival at the PED. Adrenaline was administered in 92 cases in ED. Overtreatment occurred in two cases (0.8%), while undertreatment was seen in 40 cases (16.5%), with a significantly higher rate in 2003–2007 compared to 2013–2017 (p=0.007).  Steroids (p<0.01) and antihistamines (p=0.013) were used more frequently in 2003-2007. There was no significant difference in i.v. fluid administration. There were 29 instances where an AAI was indicated but not dispensed; this occurred less frequently in 2013-2017 (p=0.049).

Rates of anaphylaxis in children 0-2 years are increasing. Recognition is often a challenge as infants and toddlers can present with phenotypes that differ from those seen in older children. Greater awareness of these age-specific symptom patterns is crucial for timely recognition and appropriate management.