title: AAAAI/ACAAI surveillance study of subcutaneous immunotherapy, years 2008-2012: an update on fatal and nonfatal systemic allergic reactions.
abstract: BACKGROUND
  Before 2002, there were an estimated 3.4 fatal reactions per year to subcutaneous allergen immunotherapy (SCIT). Recent incidences of SCIT-related systemic allergic reactions (SR) and fatal reactions are not well defined.
  
  
  OBJECTIVE
  To define the incidence of and clinical practices associated with SRs to SCIT and skin testing.
  
  
  METHODS
  From 2008 to 2012, 27% to 49% of the American College of Allergy, Asthma, and Immunology and American Academy of Allergy, Asthma, and Immunology members completed an annual survey of SCIT-related fatal and nonfatal SRs of varying severity. A shortened version of the World Allergy Organization (WAO) classification system for SRs was adopted in 2011 (grade 1, mild; grade 2, moderate; grade 3, severe; grade 4, very severe). From 2011 to 2012, data were collected regarding nonfatal SRs to skin testing and strategies to lower the risk of SRs from SCIT.
  
  
  RESULTS
  Between 2008 and 2012, data were gathered on 23.3 million injection visits. One confirmed fatality occurred in 2009. Overall SR rates remained stable at 0.1%. The rate of very severe, WAO grade 4, SRs was similar to previously reported rates of near-fatal reactions (1 in 1 million injections). Although almost one-third of practices experienced at least 1 SR from skin testing, no WAO grade 3 or 4 SRs from skin testing were reported. A lower target dose during cluster buildup before transitioning to maintenance may be associated with a lower risk of WAO grade 3 SRs (P = .07). Dose adjustment during pollen seasons was associated with fewer WAO grade 3 or 4 SRs (P < .001).
  
  
  CONCLUSIONS
  Although SR rates have remained stable and fatalities appear to be declining, continued vigilance regarding SCIT safety is recommended. Additional surveillance and study regarding methods to decrease the risk of severe SRs is warranted.
authors.affiliation: Division of Immunology, Allergy and Rheumatology, Department of Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio; Allergy Partners of Central Indiana, Indianapolis, Ind. Electronic address: epsteite@uc.edu.
authors.forename: Tolly G
authors.initials: TG
authors.lastname: Epstein
authors.affiliation: Gage Occupational and Environmental Health Unit, Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Gary M
authors.initials: GM
authors.lastname: Liss
authors.affiliation: Bernstein Clinical Research Center LLC, Cincinnati, Ohio.
authors.forename: Karen
authors.initials: K
authors.lastname: Murphy-Berendts
authors.affiliation: Division of Immunology, Allergy and Rheumatology, Department of Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio; Bernstein Clinical Research Center LLC, Cincinnati, Ohio.
authors.forename: David I
authors.initials: DI
authors.lastname: Bernstein
mesh_terms: D003888:Desensitization, Immunologic / Q000009:adverse effects*; D006801:Humans; D006967:Hypersensitivity / Q000453:epidemiology*; D007279:Injections, Subcutaneous; D012882:Skin Tests; D013997:Time Factors
keywords: Allergy shots; Anaphylaxis; Cluster immunotherapy; Pollen season; Subcutaneous allergen immunotherapy; Systemic reactions