Is unrecognized anaphylaxis a cause of sudden unexpected death?

Clin Exp Allergy. 1995 Sep;25(9):866-70. doi: 10.1111/j.1365-2222.1995.tb00029.x.


Background: Serum tryptase levels reflect mast cell activation and correlate with anaphylactic reactions. Elevated post-mortem serum tryptase levels have been found in witnessed fatal anaphylaxis.

Objective: This study was designed to examine whether or not unwitnessed anaphylaxis may be a hitherto unrecognized cause of sudden unexplained death.

Methods: Mast cell tryptase was measured by immunoassay in 68 post-mortem sera remaining from a previous study which reported elevated venom-specific IgE antibodies in 22 (23%) of 94 victims of sudden unexpected death. Autopsies were performed in all cases. The cause of death was independently reported by pathologists unfamiliar with the nature of this study.

Results: Serum tryptase levels were elevated (> 10 ng/mL) in nine of 68 cases. The levels could not be predicted from the clinical circumstances surrounding death. Sera from four individuals contained both elevated tryptase and previously reported elevated venom-specific IgE.

Conclusions: We conclude that mast cell activation may accompany up to 13% of sudden unexpected deaths in adults. Measurement of both tryptase and specific IgE antibody levels in post-mortem sera from persons experiencing sudden, unexpected death may identify a small subset of cases due to clinically unrecognized fatal anaphylaxis, including those due to insect stings.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Anaphylaxis / enzymology*
  • Animals
  • Arthropod Venoms / immunology
  • Cause of Death
  • Chymases
  • Death, Sudden / etiology*
  • Female
  • Humans
  • Immunoglobulin E / blood
  • Insect Bites and Stings / blood
  • Insect Bites and Stings / immunology
  • Male
  • Mast Cells / enzymology
  • Middle Aged
  • Serine Endopeptidases / blood*
  • Tryptases


  • Arthropod Venoms
  • Immunoglobulin E
  • Serine Endopeptidases
  • chymase 2
  • Chymases
  • Tryptases