Radiocontrast Media Allergic Reactions and Interventional Pain Practice—A Review

Background: Millions of interventional pain procedures are performed each year in the UnitedStates. Interventional pain physicians commonly administer radiocontrast media (RCM) underfluoroscopy for these procedures. However, RCM can cause various types of hypersensitivity orallergic type reactions, in an acute or delayed fashion. Furthermore, some patients report a priorhistory of hypersensitivity reactions to RCM when presenting to the interventional pain clinic.Both scenarios present challenges to the interventional pain physician.Objective: To describe the various types of hypersensitivity reactions to RCM, as well as strategiesto prevent and manage these reactions, within the context of interventional pain practice.Method: A review of the literature from 1975 through 2011 regarding allergic type reactions toRCM, as well as iodine, and shellfish allergy, was undertaken in an effort to review and developrecommendations on managing these patients presenting to the interventional pain clinic.Keywords used in the literature search were: radiocontrast media, contrast allergy, contrastreaction, iodine allergy, shellfish allergy, and fluoroscopy. The included articles were concernedwith the basic or clinical science of contrast allergy, including the physiology, epidemiology,diagnosis, and management of such reactions. Meta-analysis, review articles, and case reportsaddressing contrast media reactions were also included. Articles which discussed contrast mediareactions in a peripheral fashion were excluded.Results: In reviewing the literature, it is apparent that the mechanisms and pathophysiology ofRCM hypersensitivity reactions are still being characterized, which should soon lead to improvedscreenings, as well as prevention and treatment strategies. Many common themes are describedthroughout the literature regarding patient risk factors, testing, prevention, diagnosis, andtreatment of RCM allergic-type reactions.Limitations: The current review did not perform a meta-analysis of the available data, as mostof the available articles were trials that were randomly controlled. Therefore, the conclusions ofthe present article are general, and qualitative in nature.Conclusion: Although the mechanisms of various RCM allergic-type reactions are not entirelyunderstood, the interventional pain physician should have a basic understanding of patient riskfactors, prevention, diagnosis, and treatment of these reactions. The current review allowed forprevention and treatment strategies for managing patients with RCM hypersensitivity reactions.Key words: Radiocontrast media, contrast allergy, contrast reaction, iodine allergy, shellfish,allergy, fluoroscopy, interventional spine practice