D3.277 - Features of severe anaphylaxis in children, data from the Moscow Pediatric Register

Since 2022, the first Pediatric Moscow Anaphylaxis Registry has started working at the Morozov Children's Hospital.

The aim of the study was toobjectivize and analyze data from the anaphylaxis register “Pediatrics of Moscow” to determine the features of severe AF in children of the Moscow region.

Statistical analysis of patient-oriented questionnaire data from 69 children aged 0 to 18 years who were prospectively included in the registry during emergency hospitalization for AF was performed. Informed consent was obtained from all patients and their parents/guardians. The research was supported by a grant from the Government of Moscow (No. 0408-1).

The proportion of patients with severe AF was 30% (n=21), with the highest frequency noted among patients in the 0-3- and 13-18-year groups (44% and 35% respectively). Food triggers were the most significant cause of AF in the total group (84%). In mild AF, food was the trigger in 50% of cases, moderate and severe AF in 95% and 75%, respectively. The most frequent triggers of severe food AF were tree nuts (31%), cow's milk allergens (19%), and confectionery (13%). The central nervous and cardiovascular systems were more frequently involved in severe AF compared to the mild/moderate AF groups (86% vs 25%, 81% vs 30% respectively, p<0.001). Among patients with severe AF, the highest percentage of reactions (63%) developed within the first 15 minutes after exposure to the trigger, while among children with mild/moderate AF, a greater proportion of reactions developed within 15-30 minutes (71%) (p=0.001). At the stage of emergency medical care, the diagnosis of AF was significantly more frequent in severe compared to moderate reactions (57% vs 12% respectively, p=0.001).

Data from the Pediatric Moscow Anaphylaxis Registry show that severe AF in children accounts for about one third of cases. Food triggers are the most significant cause of AF in children regardless of its severity.  Severe food AF is often induced by tree nuts and cow's milk. Severe anaphylactic reactions are characterized by high frequency of involvement of cardiovascular, central nervous system, extremely rapid development of symptoms. In severe AF the diagnosis is verified in more than half of cases.