Clinical Follow-up in Patients With Moderate or Severe Allergic-Like Reactions to Iodinated Contrast Material

Objective: To examine follow-up care in patients with a history of acute allergic-like reaction to iodinated contrast material (ICM), including subsequent imaging management, allergy consultation, and repeat ICM exposure and reactions. Methods: All patients who had a moderate or severe acute allergic-like reaction to ICM after contrast-enhanced CT (CECT) examination from June 1, 2009, to January 1, 2022, at our institution were included. Chart review was performed to determine (1) whether subsequent imaging was not performed or was altered in these patients, (2) whether the patient underwent a subsequent CECT examination, and (3) whether the patient had an allergist consultation. Results: A total of 251 patients were identified. One-third of patients (90 of 251, 36%) had at least one change to their subsequent imaging management due to their reaction, including performing an unenhanced CT (62 of 251, 25%) or MRI (22 of 251, 8.8%) instead of a CECT or not performing a CECT when otherwise clinically indicated (20 of 251, 8.0%). Patients with a prior severe reaction were more likely to have a change in management than patients with a prior moderate reaction (severe: 22 of 32 [69%] versus moderate: 68 of 219 [31%], P < .0001). Only 17 patients (6.8%) had an allergy consult for their ICM reaction. A total of 90 patients underwent 274 subsequent CECT examinations. Repeat allergic-like reactions were observed in one quarter of patients (24 of 90, 27%) and a tenth of CECT examinations (29 of 274, 11%). Discussion: One-third of patients with a history of a moderate or severe allergic-like reaction to ICM had their subsequent imaging care modified due to their reaction.