Pediatric anaphylaxis: triggers, clinical features, and treatment in a tertiary-care hospital.

Background: Anaphylaxis is a life-threatening condition. There are limited data about its etiology and clinical characteristics in Asian children with anaphylaxis.

Objective: To investigate triggers, presenting symptoms, treatment and clinical course of anaphylaxis in Thai children.

Method: Medical record of children who were diagnosed with anaphylaxis between 2004 and 2013 at Ramathibodi Hospital, Bangkok, Thailand were reviewed.

Results: One hundred-seventy two episodes of anaphylaxis occurred in 160 children (91 boys, 69 girls) aged 3 months to 18 years. Anaphylaxis increased from 2.7 cases/1000 pediatric admission to 4.51 cases/1000 pediatric admission between 2004-2008 and 2009-2013. The main causes were food (34.92%), drug (33.1%), blood components (23.8%), insect sting (9%), and unidentified causes (2.8%). Allergy to the triggers was known prior to anaphylaxis in 42 episodes (24.6%). Treatment consisted of epinephrine intramuscularly (93.8%), corticosteroids (92.5%), H₁antihistamines (96%), H₂antihistamines (50%), and β₂agonists nebulization (35.1%). Biphasic anaphylaxis occurred in 8.7% of the documented episodes and severe anaphylaxis in 34.3% of the documented episodes. Biphasic anaphylaxis and severe anaphylaxis were associated with fewer administrations of intramuscular epinephrine (OR 0.08 [95% CI 0.014-0.43]; p =0.01 and OR 9.36 [95% CI 2.5-34.7]; p <0.001 respectively). There were no fatality cases. There were associations between triggers of anaphylaxis and atopic histories, patients with severe anaphylaxis and cardiovascular involvement (p <0.01).

Conclusions: The incidence of anaphylaxis in Thai children is increasing. Anaphylaxis in children commonly occurred without the histories of prior reaction to the causative agent. Less frequent treatment with intramuscular epinephrine was associated with biphasic and severe anaphylaxis. A better knowledge of patterns and causes of anaphylaxis might contribute to a better management.