Fatal anaphylaxis: postmortem findings and associated comorbid diseases.

Background: Anaphylaxis is an infrequent cause of sudden death. Death often results from circulatory collapse, respiratory arrest, or both.

Objective: To investigate the causes of death, anatomical findings, and comorbid diseases in cases of fatal anaphylaxis.

Methods: This is a retrospective case review of 25 unselected cases of documented fatal anaphylaxis. Each case report contained details of the fatal reaction, a review of the medical record, and laboratory and autopsy findings. Serum tryptase concentrations were measured in 7 cases.

Results: The anaphylactic deaths included 7 reactions to medications, 6 to radiocontrast material, 6 to Hymenoptera stings, and 4 to foods. The mean age was 59 years. The anaphylactic reaction began within 30 minutes of exposure in 21 of 25 cases, with death occurring within 60 minutes in 13 of 25 cases. Urticaria occurred in only 1 of 25 cases. Anatomical findings consistent with anaphylaxis were present in 18 of 23 patients undergoing autopsy. At least 1 significant comorbid disease was identified in 22 of 25 cases.

Conclusions: (1) Elderly patients with substantial comorbid conditions constituted a significant number of the anaphylactic fatalities; (2) the onset of severe anaphylaxis occurred in less than 30 minutes in nearly every case; (3) 18 of 23 cases were associated with specific anatomical findings of anaphylaxis; (4) self-administered epinephrine was used in just 1 of 5 cases; and (5) serum total tryptase concentrations were elevated markedly in 4 of 7 cases tested.