Risk factors in fatal cases of anaphylaxis due to contrast media: A forensic evaluation

Background: Fatalities following contrast medium exposure are extremely rare in clinical routine, though they may occur as an exception. Some may fall under the purview of the inquiring authorities and forensic pathologists due to their inhospital occurrence. The purpose of this study was to assess the risk factors for anaphylaxis due to contrast medium administration that can be identified in fatal cases.Methods: Fatalities occurred during the course of clinical investigations with contrast media described in the literature and fatal reactions to contrast agents that had undergone forensic investigations in our medicolegal center were reviewed with respect to patient characteristics, administered contrast medium, performed biochemical investigations and potential risk factors identified based on clinical history and medical records.Results: Biochemical investigations into the fatal cases examined in our facility revealed increased mast cell tryptase, total IgE and activated mast cells in all subjects. Data obtained from the literature and our own investigations indicated that in only a minority of the fatal cases had there been previous exposure to contrast compounds, while most cases of severe anaphylaxis involved patients who apparently reacted on initial exposure.Conclusions: Most fatal cases failed to present any identifiable predisposing conditions out of those traditionally considered as risk factors for an anaphylactic reaction to contrast compounds in the medical histories of the patients. Comprehensive clinical histories and thorough reviews of medical data, along with exhaustive forensic investigations, provide information that is relevant in order to better appreciate the interwoven relationships linking all factors potentially involved in the pathogenesis of fatal anaphylaxis to contrast media.