The involvement of osmolarity in the safety of contrast media

BACKGROUND: New non-ionic contrast agents, classified into low osmolar agents and iso-osmolar agents, present different biochemical characteristics that may influence the allergic reactions they cause. The aim of our study was to evaluate how osmolarity may affect safety in the use of contrast agents. CASE PRESENTATION: Six patients with a positive history for reaction to contrast agent were included in this study. Only one patient prick and intradermal skin test was positive. However, in 5 cases, patients presented an immediate reaction after administration of contrast agent that was not IgE mediated. CONCLUSIONS: In this study, we focused on iodixanol, an iso-osmolar contrast agent, finding good safety of this product in patients with previous hypersensitivity reactions to contrast agent.