Anaphylaktoide Reaktionen nach Infusion von Rontgenkontrastmitteln

Modern radio contrast media (RCM) include ionic and nonionic agents as well as monomers and dimers. Anaphylactoid reactions to RCM occur in 4-13% of infusions and are relatively frequent. The tolerance of nonionic RCM is substantially increased, however, recently, also after infusion of these substances, severe reactions and even fatalities have been described. Recent reports about anaphylactoid 'late' reactions deserve increasing interest. The pathomechanisms of these reactions are unclear. Whereas in immediate-type reactions pseudo-allergic mechanisms seem to be responsible, in late reactions positive skin testings could be demonstrated, which could indicate a possible allergic mechanism. For prophylaxis of anaphylactoid RCM-induced reactions the application of non-ionic substances and a premedication with H1 and H2 antagonists as well as glucocorticosteroids is recommended. The therapy of acute symptoms follows the severity-related guidelines for the therapy of anaphylactoid reactions.