Current Epidemiology and Management of Radiocontrast-Associated Acute- and Delayed-Onset Hypersensitivity: A Review of the Literature

Radiocontrast-associated acute-onset hypersensitivity reactions now occur less frequently than before 1990, when high-osmolar, ionic, radiocontrast agents were widely used. Premedication with corticosteroids and antihistamines does not reliably prevent recurrent low-osmolar radiocontrast-associated acute hypersensitivity reactions. Corticosteroid prophylaxis for acute hypersensitivity currently causes more morbidity than benefit. The specific radiocontrast agent that is associated with a patient's adverse reaction must be displayed in the drug intolerance or drug "allergy" field of their electronic health record to enable effective management and prevention of future reactions. The term iodine allergy should never be used in the context of radiocontrast-associated adverse reactions because it leads to poorer clinical outcomes. The time to onset of the reaction and the nature of the reaction must be noted in enough detail in the drug intolerance comment fields in the electronic health record to determine the potential mechanism for the reaction and to enable selection of the appropriate radiocontrast material for future exposures. Most individuals with a history of radiocontrast agent hypersensitivity can be effectively managed by selecting an alternative radiocontrast agent, without any premedication. Radiology Departments, catheterization laboratories, and all physicians who use parenteral radiocontrast media must have management plans in place to treat severe acute reactions when they occur. Patients should be informed that delayed-onset reactions, mostly benign rashes within one week of exposure, are as common or more common than acute reactions. Future radiocontrast-associated acute and delayed-onset reactions can be minimized, but never completely avoided, by using an appropriate alternative agent.