Vasculitis as an adverse event following immunization - Systematic literature review.

Background: Several types of vasculitis have been observed and reported in temporal association withthe administration of various vaccines. A systematic review of current evidence is lacking.Objective: This systematic literature review aimed to assess available evidence and current reportingpractice of vasculitides as adverse events following immunization (AEFI).Methods: We reviewed the literature from 1st January 1994 to 30th June 2014. This review comprisesrandomized controlled trials, observational studies, case series, case reports, reviews and commentsregardless of vaccine and target population.Results: The initial search resulted in the identification of 6656 articles. Of these, 157 articles were assessedfor eligibility and 75 studies were considered for analysis, including 6 retrospective/observational stud-ies, 2 randomized controlled trials, 7 reviews, 11 case series, 46 case reports and 3 comments. Mostof the larger, higher quality studies found no causal association between vaccination and subsequentdevelopment of vasculitis, including several studies on Kawasaki disease and Henoch-Schönlein purpura(IgA vasculitis). Smaller case series reported a few cases of vasculitis following BCG and vaccines againstinfluenza and hepatitis. Only 24% of the articles reported using a case definition of vasculitis.