The following is a summary of “Skin Test–Guided Strategy to Select Alternative Iodinated Contrast Media in Patients With Immediate Hypersensitivity Reaction: A Prospective Confirmative Study,” published in the November 2023 issue of Allergy and Clinical Immunology by Lee et al.

An IHR, or drug-induced instant hypersensitivity response, is often caused by iodinated contrast media (ICM). Because ICM has to be used more than once, there needs to be a normal way to stop IHR from happening again. For a study, researchers sought to come up with a way for past reactors to stop IHR from happening again using an intradermal skin test (IDT). 

From May 2018 to December 2020, they did a prospective joint study looking for people who had gone from IHR to ICM.  After being accepted, the subjects went through IDT with a causal ICM. The following protocol was used to choose the alternatives for reexposure: if the IDT with the culprit ICM was positive, more skin tests with other available ICM were done to find IDT-negative agents as alternatives; and if the IDT with the culprit ICM was negative, a randomly changed ICM was used without any more skin tests. In later computed tomography exams, the return and intensity of hypersensitivity were checked. In every case, premedication was given based on how bad the index event was 496 people signed up, and 299 of them were introduced to ICM again. 

228 (84.8%) of the 269 people who followed the protocol went through computed tomography exams without any problems. In contrast, IHR happened again in 16 of the 30 people who did not follow the protocol (P <.001). Using the plan also made IHR less severe in cases where it happened again (P = 0.003).  The IDT-guided approach cut down on the number of times IHR turned into ICM and made recurrent cases less severe. It was proof that an IDT is needed to find safe options and identify ICM allergies.

Source: sciencedirect.com/science/article/abs/pii/S2213219823007754