Medical and pathologic characteristics of fatal anaphylaxis: a Spanish nationwide 17-year series

Forensic series on fatal anaphylaxis are scarce, probably because the diagnosis of anaphylaxis is often complex and the incidence is low. We report on the medicolegal, demographic and histopathological characteristics of a series of sudden deaths which were investigated for anaphylaxis at the Spanish National Institute of Toxicology and Forensic Sciences (INTCF) over a 17-year period (1998-2015). A total of 122 undetermined sudden deaths from a high percentage of Spanish regions (81.5% of the total population) were sent to the INTCF with anaphylaxis as the suspected cause of death for histological, biochemical, and medicolegal investigation. Two certified allergists confirmed that 46 of the 122 cases were fatal anaphylaxis. The results indicated a median age of 51 years (IQR = 29) and a male predominance (76%). The main causes of anaphylaxis were drugs (41%), hymenoptera stings (33%), and food (13%). A previous allergic event had been reported in both food anaphylaxis (67%) and drug anaphylaxis (53%). The deaths occurred in health care settings (37%), at home (22%), and outside the home (26.09%). Histopathology data were available for 40 individuals. The most frequent autopsy findings were angioedema of the upper airways (50%), pulmonary edema (47.5%), atheromatosis of coronary vessels (32.5%), and pulmonary congestion (27.5%). Our findings for fatal anaphylaxis indicated a predominance of men, older age (≥50 years) and death in a health care setting (one-third of cases). Previous episodes had occurred in two-thirds of cases of food-induced anaphylaxis and in half of the cases of drug-induced anaphylaxis.