Abstract
Purpose of review: Serum tryptase, a mast cell marker, provides clues for the mechanism, severity, and management of drug hypersensitivity induced by immunoglobulin E dependent or independent mast cell activation. Recent findings: The interpretation of serum tryptase levels has been challenged during the last 2 years by major advances in tryptase genetics and their rapid incorporation into clinical practice. On the contrary, new pathophysiological insight into nonmast cell-dependent immediate hypersensitivity has been gained. Summary: This review provides up-to-date information on the pathophysiology and recommended use and interpretation of tryptase in the context of drug hypersensitivity reactions as a function of their endotype.