Characterization and diagnostic evaluation of hypersensitivity to iodinated contrast media: A retrospective analysis

Hypersensitivity reactions to iodinated contrast media (ICM) pose a growing clinical challenge, especially for patients requiring imaging. Differentiation of immune-mediated hypersensitivity from non-immune adverse reactions is essential to avoid unnecessary ICM avoidance and ensure safe diagnostic imaging procedures.

We conducted a retrospective analysis of 222 patients assessed for suspected ICM hypersensitivity at Vilnius University Hospital Santaros Clinics from 2017 to 2024. All patients underwent skin prick and intradermal testing. Selected individuals received intravenous provocation testing. Clinical characteristics, symptom profiles, and outcomes were assessed.

Sensitization to ICM was confirmed in 16.67% of patients, primarily via intradermal and provocation testing. Urticaria (OR = 3.93) and anaphylaxis (OR = 4.17) were significantly associated with confirmed sensitization, while isolated non-cutaneous symptoms and late-onset angioedema were not. Higher sensitization rates were observed in patients with oncologic (29.63%) and cardiovascular (20.69%) conditions, and renal pathology showed the lowest rate (2.94%). Among non-sensitized patients, 75 underwent ICM imaging without adverse reactions and were safely delabeled. Most sensitized individuals tolerated alternative ICM agents.

A tiered allergological approach using skin and provocation testing supports accurate diagnosis and risk-stratified imaging strategies, including safer alternative ICM selection and selective delabeling. Findings support early referral, personalized contrast selection, and delabeling strategies in high-risk populations.