D3.333 - Clinical Characteristics of Anaphylaxis in Infants and Toddlers

Anaphylaxis in infants and toddlers is challenging to diagnose due to limited verbal expression and symptom overlap with common pediatric conditions. This study aimed to evaluate the diagnostic characteristics, epidemiology, triggering factors, and clinical management of anaphylaxis in children aged 0–3 years.

Sixty-eight children aged 0–36 months diagnosed with anaphylaxis and admitted to the Pediatric Immunology and Allergy Clinic of Ankara Etlik City Hospital between October 1, 2022, and April 1, 2025, were retrospectively analyzed.

Among the patients, 58.8% were male, with a mean age of 15.5 ± 9.7 months; 10.3% had a prior history of anaphylaxis. Food-induced anaphylaxis (p < 0.001) and delayed-onset reactions (>15 min) were associated with prolonged hospitalization (p = 0.004), while non-food triggers were more frequently linked to ward or intensive care unit admission (p =0.02). Respiratory symptoms were more common in girls (p = 0.003), whereas gastrointestinal symptoms predominated in boys (p = 0.012).

In patients with concomitant atopy, food was more often the trigger (p < 0.001), reaction onset was earlier (p = 0.006), and cardiovascular involvement was less frequent (p = 0.008). Reactions occurring within the first 15 minutes were associated with earlier discharge (p = 0.004). Cardiovascular symptoms were strongly associated with neurological involvement (p = 0.001) and significantly longer hospital stays and higher admission rates (p<0.001). All patients with cardiovascular symptoms required hospitalization for more than 8 hours. Eosinophilia was associated with neurological symptoms (p = 0.001), whereas elevated serum tryptase levels (≥11 ng/mL) were linked to gastrointestinal manifestations (p = 0.023).

Food allergy is the leading trigger of anaphylaxis in children aged 0–3 years. The coexistence of cardiovascular and neurological symptoms represents a severe clinical phenotype and predicts the need for close monitoring and intensive care. These findings support improved risk stratification and management strategies in this vulnerable age group.