title: Recurrent reactions to food among children at paediatric emergency departments: epidemiology of allergic disease.
abstract: BACKGROUND
  Knowledge about repeated food reactions in paediatric emergency departments (ED) is sparse.
  
  
  OBJECTIVE
  To investigate the incidence and potential risk factors for repeated ED visits for food-allergic reactions among children with a prior ED visit due to reactions to food.
  
  
  METHODS
  A total of 358 children with ED visits at paediatric hospitals in Stockholm due to reactions to foods during 2007 (index-reaction) were investigated in relation to recurrent reactions until 30 June 2010. Adjusted Cox proportional hazard models were used to compute relative risks (RR) and 95% confidence intervals (CI).
  
  
  RESULTS
  A total of 80 children had 116 ED revisits over a period of 873 patient-years, yielding an incidence rate of 9 per 100 patient-years. Known food allergy before the index ED visit in 2007 increased the risk for ED revisits (RR = 2.30, 95% CI 1.35-3.94). Likewise, prescription of adrenaline auto-injector before the index-reaction increased the risk (RR = 2.02, 95% CI 1.17-3.49). Twenty-one percent of the children had more severe reactions at the revisit, 38% less severe and 41% had reactions of comparable severity. However, among 44% of the children with comparable or less severe reaction at revisit, early treatment with adrenaline hampered the classification of change in severity.
  
  
  CONCLUSIONS
  Previously known food allergy and prior prescription of adrenaline are significant risk factors for ED revisits among children with a prior ED visit due to reactions to food. Our results indicate that the severity of the index-reaction cannot be used to predict the severity of the relapse.
authors.affiliation: Sachs' Children and Youth Hospital, Södersjukhuset, Stockholm, Sweden; Department of Clinical Science and Education, Södersjukhuset, Karolinska Institutet, Stockholm, Sweden.
authors.forename: M
authors.initials: M
authors.lastname: Vetander
authors.forename: D H
authors.initials: DH
authors.lastname: Ly
authors.forename: N
authors.initials: N
authors.lastname: Håkansson
authors.forename: G
authors.initials: G
authors.lastname: Lilja
authors.forename: C
authors.initials: C
authors.lastname: Nilsson
authors.forename: E
authors.initials: E
authors.lastname: Östblom
authors.forename: M
authors.initials: M
authors.lastname: Wickman
authors.forename: A
authors.initials: A
authors.lastname: Bergström
mesh_terms: D000293:Adolescent; D000707:Anaphylaxis / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D015897:Comorbidity; D004636:Emergency Service, Hospital; D004837:Epinephrine / Q000008:administration & dosage; D005260:Female; D005512:Food Hypersensitivity / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology*; D006801:Humans; D006967:Hypersensitivity / Q000453:epidemiology; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D055118:Medication Adherence; D012306:Risk; D012307:Risk Factors; D012720:Severity of Illness Index
chemical_list: D004837:Epinephrine
keywords: anaphylaxis; children; emergency department; food allergy