Hypersensitivity reactions to contrast media: Part 2. Prevention of recurrent hypersensitivity reactions in adults. Updated guidelines by the ESUR Contrast Media Safety Committee

Abstract: Hypersensitivity reactions to contrast media are infrequent and can occur either within the first 60 min following their intravascular administration (immediate reactions) or at a later time point (non-immediate reactions). Most hypersensitivity reactions are mild or moderate, while severe reactions are rare (less than 1 in every 10,000 administrations). After any moderate or severe immediate adverse reaction, serum tryptase must be measured within 1–4 h from the onset of symptoms and at least 24 h after symptoms have disappeared to confirm a hypersensitivity reaction. At least for all moderate-to-severe hypersensitivity reactions, the patient should be referred to a drug allergy specialist for an allergy evaluation with a panel of contrast media, and optionally, all hypersensitivity reactions when local drug allergy specialist capacity allows. Selecting an alternative contrast medium based on practical experience is challenging due to its high and variable cross-reactivity; therefore, the best option is to choose an alternative based on the results of an allergy evaluation. This approach is safer and more effective than premedication for preventing recurrent hypersensitivity reactions. Key Points: Question What is the optimal strategy in clinical practice to prevent recurrent hypersensitivity reactions in adults who previously experienced a hypersensitivity reaction to contrast media? Findings Serum tryptase should be measured within 1–4 h after a moderate or severe reaction, and at least all moderate or severe hypersensitivity reactions should be referred to an allergologist. Clinical relevance Management strategies should be adapted to the type and severity of the reaction, as well as the urgency of required re-administration. Changing from the culprit contrast agent to another molecule with differing side-chains is more effective than premedication.