188: Corticosteroids and Antihistamines in the Treatment of Anaphylaxis: A Systematic Review

Abstract

Introduction: The wide variability in prescribing patterns and adherence to guidelines for the acute management of anaphylaxis may be partially justified by the paucity of randomized controlled trials examining the efficacy of pharmacological treatment. The objective of this study was determine if the use of epinephrine, corticosteroids or antihistamines affect rates of biphasic reactions in patients presenting to the emergency department (ED) with anaphylaxis. Methods: We searched Medline (1946-September 2013) and EMBASE (1974-September 2013) using a peer-reviewed search string to identify original, English-language studies describing pharmacological intervention for patients of all ages presenting to the ED with anaphylaxis. Exclusion criteria included single case reports, review articles, or treatment not reported. The primary outcome was the association of pharmacological treatment with biphasic reaction. Secondary outcome was the adherence to recommended guidelines for the use of pharmacotherapy in anaphylaxis. Results: Of 1424 citations, 1153 remained after removal of duplicates. After dual review, 35 observational studies remained. Twenty-seven studies were included in qualitative analysis, and seven studies were included in meta-analysis (pooled n=1471). Qualitative analysis revealed that current anaphylaxis guidelines are not being followed, regardless of population age or location. Corticosteroids and antihistamines are consistently prescribed more often than epinephrine. Meta-analysis revealed no significant association between of any of the medications studied and biphasic reactions. Conclusion: Minimal evidence supports the use of adjunctive therapy to prevent biphasic reaction for anaphylaxis. There is poor application of existing guidelines for the use of epinephrine in anaphylaxis, highlighting a role for further knowledge translation. Prospective, controlled clinical trials are needed to determine the role for adjunctive medications (corticosteroids, antihistamines) in anaphylaxis.