Serum tryptase: an indicator of anaphylaxis following fluorescein angiography.

Background: Anaphylaxis is a potentially fatal complication of fluorescein angiography. It is diagnosed by clinical signs. Serum beta-tryptase serves as a specific indicator of mast cell activation and of anaphylactic shock that can be detected by radioimmunoassay.
Method: This is a report on a 48-year-old woman who developed anaphylaxis during fluorescein angiography. This study investigates the role of beta-tryptase in anaphylactic shock resulting from intravenous fluorescein angiogram.
Results: A serum sample of beta-tryptase collected at the time of an adverse reaction to fluorescein angiography was determined by radioimmunassay to be elevated above 20 ng/ml (normal level <1 ng/ml). This indicates massive mast cell activation and anaphylactic shock.
Conclusion: This case is the first in which elevated levels of beta-tryptase in serum indicated that the systemic adverse reaction to fluorescein was mast cell dependent. Additionally, beta-tryptase levels can be assayed to detect anaphylactic reactions several hours after a precipitating event.