Background: Increased serum tryptase has been linked to the severity of the reaction after Hymenoptera stings. The aim of the study was to measure basal tryptase levels in patients with Hymenoptera venom allergy and investigate the possible correlation between these levels and the severity of sting reaction.

Methods: One hundred nine patients were included in the study. Sixty-three were wasp venom-allergic and 46 were honey bee venom-allergic. Basal serum tryptase levels were measured by UniCAP.

Results: Basal serum tryptase levels were elevated in 12 (11%) of the 109 patients. Levels were 5.14 μg/L (3.62-5.84), 5.3 μg/L (2.94-6.54), 5.18 μg/L (3.71-6.25), and 6.98 μg/L (4.78-12.6), for patients with sting reactions of grade I, II, III and IV (as classifi ed
by Mueller), respectively. Basal serum tryptase levels correlated signifi cantly with the sting reaction severity (r = 0.2752; P = .004) and with age (r = 0.2906; P = .002). Sting reaction severity also correlated with age (r=0.3654; P = .001).

Conclusions: Basal serum tryptase levels were found to be elevated in 11% of venom allergic patients and correlated significantly with both sting reaction severity and age.

Key words: Tryptase. Hymenoptera venom allergy.