Triggers, clinical spectra and outcomes of pediatric anaphylaxis in a tertiary center: impact of comorbidities and cofactors on severity

Abstract Purpose Anaphylaxis is a potentially life-threatening systemic hypersensitivity reaction. While triggers, clinical manifestations, and severity are influenced by age and sociocultural factors, most evidence regarding the impact of comorbidities and cofactors comes from adult studies. This study aimed to characterize the triggers, clinical features, and outcomes of pediatric anaphylaxis in a tertiary care center, with a particular emphasis on risk factors for severity. Methods We retrospectively reviewed records from August 2023–August 2024 at the European Allergy Academy and Clinical Immunology Center of Excellence in Istanbul. Children aged 0–18 years ( n  = 100) with anaphylaxis as defined by the 2020 World Allergy Organization (WAO) criteria were included. Demographic, clinical, and follow-up data were collected. The updated 2024 (WAO) grading system was used to classify severity. Results Of the 3,959 records, 100 children fulfilled the inclusion criteria. A female predominance was noted in those ≤ 4 years, with males predominating thereafter. Medications were the leading trigger, followed by food, venom, and idiopathic causes. Foods were more prevalent among outpatients, and drugs were more prevalent among inpatients. Comorbidities were more common in hospital-onset anaphylaxis. Atopy was more common in food-induced anaphylaxis, whereas infections and polypharmacy were more common in drug-induced cases. Food-related reactions with endogenous factors were typically milder, whereas drug-related reactions—especially in older patients with polypharmacy or hospital-onset—tended to be more severe. Biphasic reactions were associated with delayed presentation, elevated WBC/ANC, and older age. Intramuscular adrenaline was administered in 95% of the patients, but prehospital autoinjector use was rare. Conclusion Our findings underscore the need for early recognition and management, systematic evaluation of contributing factors, risk-adapted monitoring, and individualized follow-up in pediatric anaphylaxis patients.