Causes and clinical symptoms of anaphylactic reactions in children: experience of the first «Pediatric Moscow Anaphylaxis Registry» in the Russian Federation

BACKGROUND: In Russian, there was a problem of the lack of registry of anaphylaxis, as the most important tool for monitoring this group of patients. Since 2022, the first "Pediatric Moscow Anaphylaxis Registry" has started working at the Morozov Children's Hospital. AIMS: Analysis of data from the Pediatric Moscow Anaphylaxis Registry to determine frequency, causes andclinical characteristics of anaphylaxis among children of the Moscow region. MATERIALS AND METHODS: Statistical analysis of the questionnaire data of 69 children aged 0-18, who were prospectively included in the Register during emergency hospitalization due to anaphylaxis, was carried out. RESULTS: The incidence of anaphylaxis among children hospitalized with acute allergic reactions from May 2022 to September 2023 was 5.8%. Higher percentage of anaphylaxis (38%) were observed among adolescents aged 13-18, three patients developed anaphylaxis in the first year of life (minimum age 1 month). Boys (70%) prevailed among patients under the age of 13, and girls (56%) prevailed among adolescents aged 13-18 (p=0.042). 75% anaphylaxis developed at home. Food anaphylaxis was dominant (75%-91%). Tree nuts were the most common trigger of food anaphylaxis – 35%, and confectionery products - 17%. 56% of children experienced symptoms from 4 or more organ systems, the most common symptoms were: skin/mucous (94%), respiratory (78%) and laryngeal symptoms (64%). Emergency care, diagnosed anaphylaxis in 22%, administration of epinephrine was 54%. The frequency of epinephrine use among children under 3 years was lower compared to adolescents aged 13-18 (25% vs 76%, p=0.003). CONCLUSIONS:Data from the "Pediatric Moscow Register of Anaphylaxis" showed a high incidence of anaphylaxis among patients with acute allergic reactions. More than 1/3 of anaphylaxis occurs in adolescents aged 13-18 years, anaphylaxis occurs in the first month of life. Most often, anaphylaxis occurs at home, which requires training patients to eliminate the trigger. The dominant cause of anaphylaxis in children in the Russian, regardless of age, are food allergens, tree nuts induce food anaphylaxis in more than 1/3 of cases. The emergency care diagnoses anaphylaxis in 22% of cases, epinephrine is administered in 54%, minimal use of epinephrine was among children under 3 years of age.