Background: Millions of interventional pain procedures are performed each year in the United
States. Interventional pain physicians commonly administer radiocontrast media (RCM) under
fluoroscopy for these procedures. However, RCM can cause various types of hypersensitivity or
allergic type reactions, in an acute or delayed fashion. Furthermore, some patients report a prior
history 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 strategies
to 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 to
RCM, as well as iodine, and shellfish allergy, was undertaken in an effort to review and develop
recommendations on managing these patients presenting to the interventional pain clinic.
Keywords used in the literature search were: radiocontrast media, contrast allergy, contrast
reaction, iodine allergy, shellfish allergy, and fluoroscopy. The included articles were concerned
with the basic or clinical science of contrast allergy, including the physiology, epidemiology,
diagnosis, and management of such reactions. Meta-analysis, review articles, and case reports
addressing contrast media reactions were also included. Articles which discussed contrast media
reactions in a peripheral fashion were excluded.
Results: In reviewing the literature, it is apparent that the mechanisms and pathophysiology of
RCM hypersensitivity reactions are still being characterized, which should soon lead to improved
screenings, as well as prevention and treatment strategies. Many common themes are described
throughout the literature regarding patient risk factors, testing, prevention, diagnosis, and
treatment of RCM allergic-type reactions.
Limitations: The current review did not perform a meta-analysis of the available data, as most
of the available articles were trials that were randomly controlled. Therefore, the conclusions of
the present article are general, and qualitative in nature.
Conclusion: Although the mechanisms of various RCM allergic-type reactions are not entirely
understood, the interventional pain physician should have a basic understanding of patient risk
factors, prevention, diagnosis, and treatment of these reactions. The current review allowed for
prevention 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