Skin Testing for Suspected Iodinated Contrast Media Hypersensitivity.

Area of Science:

• Allergy and Immunology
• Radiology
• Pharmacology

Background:

• Iodinated contrast medium (ICM) hypersensitivity management is debated.
• Skin testing is proposed to identify allergic patients, alongside avoidance or provocation.
• Premedication strategies are also considered for ICM hypersensitivity.

Purpose of the Study:

• To evaluate the negative predictive value (NPV) of skin testing for iodinated contrast medium (ICM) hypersensitivity.
• To assess the safety of ICM re-exposure in patients with negative skin tests.
• To determine the efficacy of skin testing in managing ICM allergy.

Main Methods:

• Retrospective evaluation of 597 patients with ICM hypersensitivity reactions over 13.5 years.
• Skin testing performed to assess for ICM allergy.
• Patients with negative skin tests were assessed for tolerance upon re-exposure to ICM.
• Premedication advised only for specific patient groups with negative skin tests.

Main Results:

• Overall NPV of skin testing for ICM was 93.1%.
• NPV for immediate hypersensitivity was 94.2%, and for nonimmediate was 86.1%.
• Re-exposure to ICM was tolerated in 93.1% of patients with negative skin tests.
• Premedication was associated with a higher incidence of reactions.

Conclusions:

• Skin testing is valuable for identifying safe ICM alternatives for re-exposure, particularly in immediate hypersensitivity.
• Patients with skin test-proven ICM allergy can often be safely re-exposed.
• Reactions upon re-exposure are infrequent, mostly mild, and can occur even with premedication.