Diagnosis of iodinated contrast media hypersensitivity: results of a 6-year period

Background Iodinated contrast media (ICM) hypersensitivity reactions represent a serious problem. Very few clinical data concerning systematic skin testing to ICM are available. Objective To evaluate the utility of ICM skin testing in patients with ICM hypersensitivity. Material and methods All patients referred over a 6-year period for ICM hypersensitivity past reactions were skin tested for (a) the implicated ICM, or (b) a set of ICM if they were positive for the implicated ICM or if its name was unknown. Results Forty-four patients, with a median age of 56 years, were studied (15 males, 29 females). The ICM skin tests were positive in 10 patients (23%): one had a positive skin prick test, seven an immediate positive intradermal test (IDT) and two a delayed positive IDT. Skin tests were more often positive in patients with immediate (9/32) as compared with those with non-immediate reactions (1/11). The time interval between the reaction and skin testing was shorter for those patients with an immediate ICM reaction and a positive skin test result (3 months [2.5-174.0]) as compared with those with an immediate ICM reaction and a negative skin test (48 months [6.8-159.0]), (P < 0.05). Respiratory allergy was more frequent in the positive group (6/10 vs. 7/34, P < 0.05). Conclusions Skin tests with ICM are positive in a subgroup of patients with ICM hypersensitivity and may play an important role in the diagnosis of ICM allergy.