Allergy to Radiocontrast Dye

Diagnosis and Prevention of Hypersensitivity Reactions to Iodinated Contrast Media

“…While there is no specific recommendation in the guideline from the American College of Radiology, the position papers from European academic societies and expert guidelines recommend that an allergy test such as a skin test should be performed appropriately to differentiate an IgE-mediated allergic reaction and used to select an alternative ICM ( Table 1 ). 3 There are still many remaining unresolved issues such as determining the appropriate test target and optimal concentration of ICM, establishing an accurate test method and standardizing it, interpreting the cross-reactivity among ICMs and identifying the role of premedication such as antihistamines and steroids. In this section, we will review data on determining the appropriate skin test target, establishing an accurate skin test method, selecting a safe ICM by interpreting the cross-reactivity found in skin tests, and identifying the role of premedication.…”

“…A short-term prescription of topical and oral steroids is recommended if symptoms recur after leaving the medical facility. 3 …”

“…Recent guidelines indicate the need for skin testing, particularly for patients with severe allergic reactions and anaphylaxis, to select a safe alternative ICM that shall be tolerated in the future. 3 However, since the majority of patients with a mild degree of immediate ICM hypersensitivity do not react to any ICM in skin tests, the mechanism of the reaction remains unclear. Furthermore, since BAT and LTT are not available beyond the experimental setting, their potential roles are not validated.…”

“…According to the time of onset after exposure to ICM, hypersensitivity reactions (HSRs) to ICM can be categorized as either immediate reactions, which usually occur within 1 hour and up to 6 hours after exposure to ICM, or delayed reactions, which occur after 1 hour and up to several days following exposure. 3 The prevalence of immediate reactions to the non-ionic low-osmolar ICMs currently used for intravascular enhancement has been reported to be about 0.2%–3%, and for delayed reactions about 1%–3%. 4 5 6…”