A. Immediate reactions.

		Allergic to multiple ICM n = 8	Allergic to a single ICMn = 4	p
Age; median (interquartile range) years		59 (49–65.5)	55 (38.25–62.25)	0.6278
Gender; n (%) female/n (%) male		5 (62.5)/3 (37.5)	2 (50)/2 (50)	1
Symptoms reported; n (%)	Anaphylaxis Urticaria	4 (50) 4 (50)	1 (25) 3 (75)	0.5758
ICM involved	Iodixanol Iomeprol Iohexol Iopramide Unkown	4 (50) 2 (25) 1 (12.5) – 1 (12.5)	– 1 (25) – 1 (25) 2 (50)	NA 1 NA NA 0.2364
Time interval between ICM administration and reaction onset; n (%)	≤30 min 31–59 min	7 (87.5) 1 (12.5)	2 (50) 2 50)	0.2364
N° of episodes	1 episode 2 episodes	8 (100) –	4 (100) –	1
Positive results in STs		5/8; 62.5% Iomeprol 3 Iohexol 3 Iodixanol 3 Iobitridol 1	1/4; 25 Iohexol 1	0.5455