Anaphylaxis is a serious life-threatening allergic disease in children. This study is aimed at determining the characteristics of pediatric patients who experienced anaphylaxis along with treatments administered in order to determine the usefulness of tryptase level assessment as a marker of anaphylaxis in Korean children. A total of 107 patients who were diagnosed with anaphylaxis in a single pediatric emergency center over a 3-year period were included in the study. Patient clinical characteristics, symptoms, signs, allergy history, trigger factors, treatments, and laboratory findings, including serum tryptase levels, were included in the analysis. Food allergies (39.3%) were the most commonly reported patient allergic history, and 58 patients (54.2%) were triggered by food. Among this group, nuts and milk exposure were the most common, affecting 15 patients (25.9%). History of anaphylaxis and asthma were more common in severe anaphylaxis compared to mild or moderate anaphylaxis cases. Epinephrine intramuscular injection was administrated to 76 patients (71.0%), and a self-injectable epinephrine was prescribed to 18 patients (16.8%). The median tryptase level was 4.80 ng/mL (range: 2.70-10.40) which was lower than the 11.4 ng/mL value commonly documented for standard evaluation in adults with anaphylaxis. The most common cause of pediatric anaphylaxis was food including nuts and milk. The rate of epinephrine injection was relatively high in our pediatric emergency department. The median tryptase level associated with anaphylaxis reactions in children was lower than 11.4 ng/mL. Further studies are needed to help improve diagnostic times and treatment accuracy in pediatric patients who develop anaphylaxis.Copyright © 2020 Won Seok Lee et al.