Hypersensitivity Reactions to Gadolinium-Based Contrast Agents: Update From an Allergist's Point of View

Background: The increasing use of Magnetic Resonance Imaging (MRI) has led to a rise in the administration of gadolinium-based contrast agents (GBCAs), accompanied by a growing number of reported adverse events (AEs). Objective: This review aims to provide an updated overview of hypersensitivity reactions (HSRs) to GBCAs, focusing on diagnostic and management strategies from an allergological perspective. Methods: We reviewed recent literature concerning the classification, clinical presentation, and pathophysiological mechanisms of HSRs to GBCAs. Particular attention was given to current recommendations for diagnosis, risk stratification, and prevention. Discussion: Adverse events to GBCAs are categorized into Type A reactions, which are dose-dependent and predictable, and Type B reactions, which are dose-independent hypersensitivity reactions. The latter may be allergic or non-allergic, presenting diagnostic and therapeutic challenges. Conclusions: HSRs to GBCAs, though relatively rare, require careful evaluation and tailored management. An allergological work-up, including skin testing and graded challenges when appropriate, plays a critical role in the safe re-exposure of patients with prior reactions.