Gadolinium based contrast (GBCAs) agents are routinely used for improving the clarity of body images obtained by magnetic resonance imaging (MRI). Skin tests (ST) are the main tools to investigate suspicions of GBCA hypersensitivity reactions (HR). The place of drug provocation test (DPT) is not well established.

The aim of our study was to study the negative predictive value (NPV) of ST in patients with a past-history of HR to GBCAs, by addressing the occurrence of new HR upon reexposure after the negative allergy workup.

We performed a retrospective analysis, based on the Drug and Allergy Hypersensitivity Database (DAHD) of the Allergy Unit of the University Hospital of Montpellier. Patients tested by ST with GBCAs from 2012 to 2021 were included. Information about reinjection of GBCAs, was searched on the electronic health record on hospital network and completed by a questionnaire by phone or mail, when it was not found. Patients were asked about their experience with ST and the confidence they had in the allergy work-up.

We identified 165 patients. Among them, there were 134 women (81.2%). Sixty-two patients (37.5%) answered the questionnaire by the time of the analysis (data collection ongoing). 54 patients (32.7% of the whole cohort) having an MRI were reinjected with GBCAs (which could be identified in 76% of situations). In this group, most index reactions (81.4%) were immediate, one third (19 patients, 35.2%) being anaphylactic (with or without shock). Seven patients (12.9%) described a reaction: in 2 and 3 cases the reaction was localized and generalized erythema, respectively, one case reacted with dizziness and another one described throat oedema.

Our results confirm small rates of reactions after reinjection of GBCAs, in patients with negative ST. The NPV in our study was high (87%) and the breakthrough reactions were not severe. The strength of this study is the large sample of patients followed in real-life conditions. It adds-up to the scarce knowledge of drug allergy work-up for GBCAs.