Trends in Childhood Anaphylaxis in Singapore: 2015-2022.

ABSTRACT

BACKGROUND: There has been limited data regarding the incidence of anaphylaxis in Asia. We aim to describe patterns in patient characteristics, triggers and clinical presentation of childhood anaphylaxis in Singapore. METHODS: This was a retrospective review of emergency electronic medical records of children with anaphylaxis. Patients with the allergy-related diagnoses of anaphylaxis, angioedema, allergy and urticaria based on ICD-9 codes were screened. Cases fulfilling the World Allergy Organization criteria for anaphylaxis were included. RESULTS: A total of 1188 cases of anaphylaxis were identified with a median age of 6.3 years. Extrapolating data from the study sites, from 2015 to 2022, the incidence rate of childhood anaphylaxis emergency visits in Singapore doubled from 18.9 to 38.8 per 100,000 person-years, with an incidence rate ratio (IRR) of 2.06 (95% confidence interval [CI] 1.70-2.49). In 2022, the incidence rate of food anaphylaxis was 30.1 per 100,000 person-years, IRR 2.39 (95% CI 1.90-3.01) and drug anaphylaxis was 4.6 per 100,000 person-years, IRR 1.89 (95% CI 1.11-3.25). The incidence rate in children aged 0-4 years quadrupled during the study period. Common triggers were egg (10.4%), peanut (9.3%), tree nut (8.8%), milk (8%), shellfish (7.8%) and non-steroidal anti-inflammatory drug (4.4%). The majority (88.6%) of patients were treated with intramuscular adrenaline. Total number of allergy-related visits did not increase over time between 2015 and 2019. Rates of severe anaphylaxis, namely anaphylactic shock and admission to high-dependency and intensive care, did not increase over time, with a mean incidence of 1.6, IRR 0.85 (95% CI 0.40-1.83) and 0.7, IRR 1.77 (95% CI 0.54-5.76) per 100,000 person-years, respectively. CONCLUSION: While the number of emergency visits due to childhood anaphylaxis has increased, the number of cases of allergy-related visits, anaphylactic shock and anaphylaxis requiring high-dependency and intensive care did not rise.