Death in anaphylaxis in a man with house dust mite allergy

Up to recently the post-mortem diagnosis of anaphylaxis has been based solely on circumstantial evidence. With the development of assays for mast cell tryptase it is now possible to verify cases of suspected anaphylaxis. Here we present one such case, which initially appeared to be due to sudden death of unknown cause. A 47-year-old farmer was found dead in his bathroom around midnight. Hospital records revealed that he had previously been diagnosed with an allergy to house dust mites. He had also had infrequent episodes of airway symptoms, nausea, hypotension and diarrhoea usually after going to bed. The forensic autopsy did not give any clue to the cause of death. Serum tryptase in post-mortem blood was found to be substantially elevated in two samples (170 and >200 microg/L). Analysis of allergen-specific IgE showed high values for Dermatophagoides pteronyssinus and farinae. High mite allergen levels were found in dust obtained from the patient's mattress. The results of the immunological tests support the assumption that he died of anaphylactic shock. The circumstances and the patient's history of previous attacks after going to bed point to the fact that exposure to mite contaminated food and/or exposure to mite allergens in bed might have caused his death.