Anaphylaxis and reactions to foods in children--a population-based case study of emergency department visits

Background: Information about acute reactions to foods among children is limited.

Objective: To describe the overall incidence of anaphylaxis in a paediatric emergency department (ED) setting and to describe reactions to foods in relation to sex and age, clinical characteristics and management.

Methods: In a review of medical records, children with ED visits at any of three paediatric hospitals in Stockholm County during 2007 were targeted. Inclusion criteria were any adverse reaction to foods or anaphylaxis.

Results: 383 children fulfilled the inclusion criteria of which 371 had had reactions to foods. The incidence of anaphylaxis was 32 per 100 000 person years irrespective of cause and food was involved in 92%. Tree nuts, particular cashew, and peanut were the most common eliciting foods, and in children under 3 years, reactions to these two food allergens were as common as reactions to milk and egg. Pollen-allergic children seemed to be admitted due to food-induced anaphylaxis more often during the deciduous tree pollen season compared with the rest of the year (P = 0.015). Symptoms from the lower airways occurred in 49% of children with anaphylaxis but without underlying asthma compared with 72% of children with anaphylaxis and asthma, P < 0.01.

Conclusions and clinical relevance: Reactions to peanut and tree nuts are as common as reactions to milk and egg in early life. Concomitant exposure to airborne allergens seems to increase the risk of anaphylaxis to foods. Among children with anaphylaxis, wheeze is prevalent even in children without asthma diagnosis.