Hypersensitivity to iodinated contrast products (ICP) affects 1 to 3% of injected patients. These reactions require an allergological assessment with skin tests in order to distinguish allergic immunological mechanisms from other non-specific mechanisms. Current recommendations recommend carrying out prick tests followed by intradermal reactions up to a 10th dilution. However, undiluted IDRs are carried out by several teams under certain conditions, without this having been validated. Experience tends to show that these IDRs are relevant in certain patients to make the diagnosis without risk.

Inclusion Criteria:

• Major subject (≥18 years old)
• Subject treated in the allergology department in the period from June 1, 2020 to July 3, 2023 for suspected allergic hypersensitivity to ICPs and having had at least one undiluted intradermal reaction to one or more ICPs.
• Absence of written opposition in the medical file of the subject (and/or their legal representative if applicable) to the reuse of their data for scientific research purposes.

Exclusion Criteria:

• Presence of opposition from the subject (and/or their legal representative if applicable) to the reuse of their data for scientific research purposes.

Major subject (≥18 years old) treated in the allergology department in the period from June 1, 2020 to July 3, 2023 for suspected allergic hypersensitivity to ICPs and having had at least one undiluted intradermal reaction to one or more ICPs.