D3.282 - Anaphylaxis to Gadoteric Acid: A Case Report

Gadolinium-based contrast agents (GBCAs) are commonly used in radiology to enhance MRI accuracy by improving identification and characterization of lesions. They are classified as linear or macrocyclic depending on their structure and as ionic or nonionic according to their net charge. While they have a good safety profile, several studies have reported adverse events associated with their use, including hypersensitivity reactions (HSRs). HSRs are rare, occurring in 0.004% to 0.7% of cases, and can be immediate or non-immediate. Immediate hypersensitivity reactions, whether IgE-mediated or not, can cause symptoms such as urticaria, angioedema, rhinoconjunctivitis, dyspnea, gastrointestinal manifestations, or anaphylaxis within one hour of contrast administration.

We present the case of a 65-year-old male patient with no known allergies and a history of L3-S1 discopathy, currently under follow-up at the Spine Unit awaiting surgical intervention. During a contrast-enhanced lumbar MRI, for which gadoteric acid was administered intravenously, the patient began experiencing a sensation of heat inside the tube. After the procedure, on his way home, he developed respiratory difficulty, glottic edema and disorientation. He was taken to a nearby healthcare center, where he received intramuscular epinephrine and intravenous corticosteroids, leading to symptom improvement but resulting in transient global amnesia during 24 hours. He had received GBCAs previously without adverse reactions.

We performed skin prick tests (SPTs) with iodinated and paramagnetic contrast agents including iodixanol, iohexol, ioversol, iobitridol, ioxaglate, iopromide, meglumine, povidone iodine, gadoxetate disodium, gadoteric acid, and gadobenic acid. 

STPs were positive for gadoteric acid (5mm) and disodium gadoxetate (4mm). Histamine control: papule of 3mm. 

The use of GBCAs in MRI studies is increasing, with anaphylaxis reported in 0.01% of cases. Our patient was diagnosed with anaphylaxis induced by gadoteric acid, a macrocyclic ionic agent, based on the temporal relationship between its administration and symptom onset, as well as the allergy study. SPTs also resulted positive for disodium gadoxetate, a linear ionic agent that was not administered in this case.

As allergic reactions to GBCAs are rare, knowledge of cross-reactivity patterns between agents remains limited, requiring further studies.