Tryptase

This test measures tryptase, an enzyme released mainly by mast cells—immune cells involved in allergic reactions. Tryptase testing can help evaluate a suspected severe allergic reaction (anaphylaxis) or investigate conditions involving increased mast cell activity or numbers, such as systemic mastocytosis. Timing matters: a sample collected soon after a reaction may be compared with a baseline sample taken after symptoms have resolved. An elevated result does not establish a diagnosis on its own, and a normal result does not rule out anaphylaxis or a mast cell disorder.