Study participants
Individuals with a history of an immediate HSR to a LOCM, who were
referred to the Allergy Clinic of Seoul National University Hospital
from June 2001 through December 2019, were potential study participants.
Those who underwent skin testing after the occurrence of HSR were
retrospectively enrolled. The data collected included their age, sex,
previous use of LOCM, types of pre-medication, detailed information on
every exposure to LOCM, and occurrence of HSR. Data was abstracted from
the Contrast Safety Monitoring and Management System
(CoSM2oS) in Seoul National University Hospital. Their
index HSR was defined as the most recent HSR occurrence prior to the
time of the skin test. HSR severity was classified into three categories
based on the American College of Radiology’s guidelines on contrast
media: mild, moderate, and severe.20 This study was
approved by the institutional ethics board of Seoul National University
Hospital (IRB No.:1601-002-729) and informed consent was not required
due to the retrospective nature of the study.