Tryptase Blood Test in Arizona

What this test measures

Mast cells are found in tissues throughout the body and release mediators such as histamine and tryptase when they are activated. Tryptase is more specific to mast cells than histamine is, which makes it a useful marker in allergy and mast cell evaluations. Levels can rise during a severe reaction and then fall again over hours.

Blood is drawn from a vein, and the sample is analyzed with an immunoassay. Timing matters: a sample collected during or shortly after a severe reaction is interpreted differently from a baseline sample taken when a person is well. When a mast cell disorder is suspected, a baseline level and sometimes a comparison over time are used.

Clinicians order tryptase testing to investigate severe allergic reactions of unknown cause, to evaluate suspected mastocytosis, and to monitor people with a known mast cell condition. A normal result does not rule out allergy, and an abnormal result does not confirm a specific trigger. The test fits into a broader evaluation.