Desensitisation as a means of preventing untoward reactions to ionic contrast media

Patients with a previous history of anaphylactic reactions to ionic iodinated contrast media were desensitised before a second radiologic examination was performed. The tolerance to the contrast medium was raised by repeated intravenous injections in increasing doses and concentrations. No serious side effects were noted when the examinations with contrast medium was repeated within a few days after the desensitisation. The positive effect of the desensitisation may depend on a successive consumption of complement proteins, probably responsible for the allergic reactions. Therefore, the available amount of complement for some days may be too low for the occurrence of a complement reaction.