Incidence, triggering factors, symptoms, and treatment of anaphylaxis in a pediatric hospital.

Objective: Assess the incidence of anaphylaxis in the emergency room (ER) of a private pediatric hospital in the city of São Paulo, Brazil, and describe associated factors.

Method: This was a cross-sectional, retrospective, and observational study based on the medical records of patients from 0 to 18 years old seen at the emergency unit during the years of 2016-2019, who had a diagnosis potentially related to anaphylaxis according to ICD-10. All medical records were individually reviewed for the presence of compatible signs and symptoms that identified "possible" cases of anaphylaxis. Cases were considered probable anaphylaxis when medical history was compatible and indicative of anaphylaxis in the opinion of at least 2 allergists.

Results: The incidence of anaphylaxis was 0.013%. Among the 56 patients identified (mean age 4.2 years), food was the most predominant suspected factor (53%), followed by unknown factors (32%), and drugs (12.5%). All patients presented with cutaneous symptoms, 74% with respiratory, and 53% with gastrointestinal. Allergic disease as a comorbidity was found in 39% of the children and 11% had a history of previous anaphylaxis. There were neither cases of syncope or shock, nor deaths. Intramuscular (IM) adrenaline was prescribed in 37.5% of cases.

Conclusions: The incidence of anaphylaxis was low when compared to the worldwide incidence. The severity of most cases was mild, cutaneous symptoms were predominant, and food was the suspected trigger most frequently associated with reactions.