Mast cell tryptase in a case of anaphylaxis due to repeat antibiotic exposure.

Mast cell tryptase can be an indicator of type I hypersensitivity reaction and thus may serve as a surrogate marker of anaphylaxis. A 34-year-old white male patient presented with a history of systemic lupus erythematosus. Shortly after administration of cefazolin for dialysis, he developed pruritus and shortness of breath. He expired an hour later. Autopsy excluded anatomic causes of death. There was an elevated postmortem mast cell tryptase level, 29.2 ng/mL. For mast cell tryptase level to be useful, the patient must survive long enough after exposure to an allergen for mast cells to release this enzyme. A credible allergen must be identified. In this case such, mast cell tryptase could establish anaphylaxis as the cause of death. The case suggests that in a patient with autoimmune disease, it may be prudent to test for immune reaction to a drug before administering it a second time via pinprick or other method.