BACKGROUND
Provocation-tests with contrast media are not standardized, and our main
objective was to evaluate a rapid provocation-test, including patients
with a history of anaphylaxis. As secondary objectives, we phenotyping
our population and proposed a predictive methodology for the outcomes of
allergy tests.
METHODSAn allergy study using iohexol, iodixanol, ioversol, and iobitridol was
conducted in patients over 18 years of age with previous
hypersensitivity reactions to iodinated contrast media. A rapid
provocation-test (100 cc administered in 12 minutes) was performed using
a non-involved iodinated contrast medium that had tested negative on
skin tests. A statistical analysis was carried out, including binary
logistic regression and cluster analysis.
RESULTSA total of 130 patients were enrolled. Ninety-six patients (74%) showed
cutaneous symptoms exclusively, while 17 patients (13%) experienced
anaphylaxis. Nine patients (7%) had positive skin-tests, and 20 of 141
provocation-tests performed were positive, all exhibiting mild cutaneous
symptoms, including in those with a history of anaphylaxis. A safe
alternative contrast medium was recommended to 122 patients (94%), with
good tolerance in 50 patients who required a new radiological
examination. We identified three patient phenotypes, each associated
with a different risk of a positive drug provocation-test. A predictive
model for the outcomes of allergy tests was obtained, but it exhibited a
low predictive capacity.
CONCLUSIONSWe confirm the efficacy and safety of a protocol including rapid
provocation-tests in patients with hypersensitivity reactions to
iodinated contrast media of varying severity. Three patient clusters
were identified, each showing a different risk level for a positive
provocation-test.