title: Clinical Approach Used in Medical Consultations for Allergic-Like Events Following Immunization: Case Series Report in Relation to Practice Guidelines.
abstract: BACKGROUND
  The Joint Task Force on Practice Parameters (JTFPP) guidelines for the investigation and reimmunization of patients who experienced allergic-like events (ALEs) after immunization are predicated on the likelihood of anaphylaxis, assessed through the time to symptom onset (≤ or >4 hours) and number of systems involved.
  
  
  OBJECTIVE
  The objectives of this study were to compare the management of a series of patients with ALE in actual practice relative to JTFPP guidelines and to discuss key concepts and considerations in their use.
  
  
  METHODS
  This retrospective study was based on a chart review of patients who consulted for suspected vaccine-associated ALEs at a large allergy department in Canada.
  
  
  RESULTS
  Only 3 of the 135 patients who presented ALEs after immunization were referred for suspected anaphylaxis. There was no significant difference in the frequency of skin testing or reimmunization of patients whatever the time to symptom onset or number of systems involved in the ALE. Eight patients whose initial ALE occurred within 1 hour after immunization had a recurrence on reimmunization. Another patient whose initial ALE occurred 10 hours after influenza immunization had throat tightening and difficulty swallowing without objective signs.
  
  
  CONCLUSIONS
  Most ALEs after immunization are not suggestive of anaphylaxis and should not be managed as such. The definition of anaphylaxis in the JTFPP guidelines is nonspecific and may need to be revisited. Restricting skin testing and graded dose reimmunization to patients whose ALE onset is ≤1 hour (compatible with IgE-mediated reaction) and to those meeting specific clinical criteria for anaphylaxis (whatever the timing) is likely a sufficiently sensitive and cautious approach.
authors.affiliation: Department of Social and Preventive Medicine, Laval University, Québec, QC, Canada.
authors.forename: Joseline G
authors.initials: JG
authors.lastname: Zafack
authors.affiliation: Department of Social and Preventive Medicine, Laval University, Québec, QC, Canada; Immunity and Infectious Diseases, Centre de recherche du CHU de Québec-Université Laval, Québec, QC, Canada; Biological and Occupational Health, Institut National de Santé Publique du Québec, Québec, Canada. Electronic address: gaston.deserres@inspq.qc.ca.
authors.forename: Gaston
authors.initials: G
authors.lastname: De Serres
authors.affiliation: Direction de la Protection de la Santé Publique, Ministère de la Santé et des Services Sociaux du Québec, Montreal, QC, Canada.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Rouleau
authors.affiliation: Immunity and Infectious Diseases, Centre de recherche du CHU de Québec-Université Laval, Québec, QC, Canada.
authors.forename: Marie-Claude
authors.initials: MC
authors.lastname: Gariépy
authors.affiliation: Immunity and Infectious Diseases, Centre de recherche du CHU de Québec-Université Laval, Québec, QC, Canada.
authors.forename: Rémi
authors.initials: R
authors.lastname: Gagnon
authors.affiliation: Immunity and Infectious Diseases, Centre de recherche du CHU de Québec-Université Laval, Québec, QC, Canada.
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Drolet
authors.affiliation: Influenza and Emerging Respiratory Pathogens, British Columbia Centre for Disease Control, Vancouver, British Columbia, Canada.
authors.forename: Danuta M
authors.initials: DM
authors.lastname: Skowronski
mesh_terms: D000328:Adult; D026683:Advisory Committees; D000707:Anaphylaxis / Q000453:epidemiology*; D002170:Canada / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D004342:Drug Hypersensitivity / Q000453:epidemiology*; D005260:Female; D006801:Humans; D007073:Immunoglobulin E / Q000378:metabolism; D008297:Male; D017410:Practice Guidelines as Topic; D012008:Recurrence; D012017:Referral and Consultation; D012189:Retrospective Studies; D012882:Skin Tests; D014611:Vaccination; D014612:Vaccines / Q000276:immunology*
chemical_list: D014612:Vaccines; D007073:Immunoglobulin E
keywords: Adverse event; Allergy; Vaccine; Vaccine safety