Clinical Characteristics and Severity of Pediatric Anaphylaxis in the Emergency Department: A Six-Year Study Based on WAO Criteria

Background Anaphylaxis is a potentially life-threatening systemic allergic reaction with an increasing incidence in children. The World Allergy Organization (WAO) recently introduced trigger-independent diagnostic criteria and severity grading, enabling standardized evaluation of acute systemic allergic reactions. Objective To evaluate clinical characteristics, etiological distribution, severity patterns, and risk factors for severe reactions in children presenting with acute systemic allergic reactions and anaphylaxis using the updated WAO criteria. Methods This retrospective study included children with acute systemic allergic reactions (WAO Grade 2–4) presenting to a tertiary university pediatric emergency department between January 2017 and December 2022. Clinical features, triggers, management, and outcomes were analyzed. Pediatric patients with confirmed anaphylaxis were divided into three subgroups based on etiology: food, drug, and other allergens. Severity was classified according to the WAO grading system, and logistic regression analysis was performed to identify independent risk factors for severe reactions. Results Among 75 children prediagnosed with anaphylaxis, 61 (81.3%) met the WAO criteria. Food was the most common trigger (49%), followed by drugs (21.3%) and other allergens (29.5%), with food-induced reactions occurring at a younger median age. Cutaneous (60.7%) and gastrointestinal symptoms (vomiting, 41.0%) were the most frequent clinical manifestations. Cardiovascular findings distinguished severe reactions, with hypotension observed in (45%) of Grade 4 cases and none in Grade 3 (p<0.001). Nausea was more common in reactions caused by other allergens compared with food (77.8% vs 11.1%, p<0.05). In multivariable analysis, drug-induced and other allergen–related reactions were associated with a lower likelihood of severe reactions compared with food-induced anaphylaxis (OR p=0.011 and OR=0.143, p=0.029, respectively). Adrenaline autoinjector were prescribed at discharge in a minority of patients, with a rate of 26.7% among food-allergic cases. Conclusion Applying the WAO criteria, cardiovascular compromise was the main determinant of severe pediatric anaphylaxis, emphasizing the need for severity-based assessment and optimized discharge practices.