Rethinking gadolinium hypersensitivity management: from corticosteroid premedication to evidence-informed alternative GBCA selection

Recurrent hypersensitivity reactions (HSRs) to gadolinium-based contrast agents (GBCAs) are increasingly recognized as contrast-enhanced MRI use expands. Current guidelines no longer uniformly recommend routine corticosteroid premedication for prior GBCA reactors, and evidence questions premedication given without agent change: breakthrough reactions occur in a pooled 39% of premedicated patients, and antihistamines can plausibly mask early anaphylaxis warning signs, though direct evidence that premedication per se worsens outcomes is lacking. Changing to an alternative GBCA-preferably selected with allergological evaluation when clinically indicated, rather than solely by structural class-is associated with substantially lower recurrence in observational cohorts and one prospective single-arm trial; premedication remains an evidence-limited adjunct in selected circumstances. Skin testing and the basophil activation test (BAT) are specialist adjuncts for identifying culprit and tolerated alternative agents; for moderate-to-severe immediate reactions, current ESUR guidance additionally recommends acute serum tryptase measurement and allergy referral. Delayed reactions, including severe cutaneous adverse reactions (SCAR), are addressed only where they require distinct management: non-SCAR delayed reactions undergo delayed-reading and patch testing (with BAT not applicable and drug provocation testing reserved for selected patients at specialist allergy centres), whereas lifelong avoidance of all GBCAs is reserved for confirmed SCAR, in which drug provocation testing is contraindicated-guideline-derived recommendations outside our formally screened immediate-HSR evidence base. We propose a practical, severity-stratified algorithm for radiology and nursing teams, labeling its elements as evidence-supported, guideline-derived, or author-proposed.