Methods: A real time recording program of ICM hypersensitivity and clinical decision support system for choosing appropriate predication launched at Seoul National University Hospital in June 2012. This system was designed to recommend physicians to prescribe premedication according to the severity of the previous reactions (chlorpheniramine 4 mg for mild, additional systemic steroid equivalent to methylprednisolone 40 mg for moderate, individualized management after allergy consultation for severe reactions).
Result: A total of 205,726 computed tomography scans using ICM were done during 2-year study period and the incidence of ICM hypersensitivity was 0.97%. Comorbid allergic diseases such as asthma, allergic rhinitis, or chronic urticaria was more common in hypersensitivity group (5.3% vs. 3.3%, p<0.001). A total of 1,402 patients with a history of previous hypersensitivity reaction (mild 80.9%, moderate 15.7%, and severe 3.4%) were re-exposed to ICM and 82.9% of patients who were managed according to the recommended premedication underwent enhanced CT without hypersensitivity (82.8%, 84.6%, 82.6% in previously mild, moderate, and severe reactions). Previous severe reaction was the major risk factor of recurrence.
Conclusion: With our premedication prescription system based on the severity of hypersensitivity reactions, enhanced CT was performed safely in most patients in all degree.