[Radiographic contrast media hypersensitivity. New understanding of pathophysiology with implications for patient management].

There has been a remarkable progress in our understanding of the pathophysiology of hypersensitivity to contrast media (CM). Immediate reactions develop within one hour after application of CM under the clinical picture of anaphylaxis. Pruritic exanthems appearing several days afterwards account for the majority of non-immediate reactions. Current evidence indicates an allergic basis of severe immediate as well as of non-immediate reactions involving CM-reactive IgE-antibodies and T-lymphocytes, respectively. Skin tests are helpful to establish the diagnosis of these reactions. The use of skin tests to predict tolerability of CM in patients with previous hypersensitivity reaction to CM is controversial. The value of cellular in-vitro tests is unknown. In patients with previous hypersensitivity to CM, premedication with antihistamins and/or corticosteroids is recommended, but current premedication protocols do not suppress all repeat reactions. European multicenter studies addressing sensitivity, specificity and predictive value of test procedures as well as prophylaxis and risk factors of CM hypersensitivity are currently ongoing.