Tryptase serum level as a possible indicator of scombroid syndrome.

Scombroid syndrome (histamine fish poisoning--HFP) is a complex of symptoms caused by biogenic amines, mainly histamine, contained in seafood. The diagnosis of HFP is quite difficult as the symptoms of this particular condition are similar to the symptoms of a normal allergic syndrome.We have collected 10 cases (3 male and 7 female) of HFP and 50 non-HFP patients (35 female and 15 male) with allergic disorders, all from the Emergency Department of Ospedale Civile Maggiore in Verona.As expected, tryptase serum concentrations of most of the patients with allergic or anaphylactic disorders were increased above normal value (24.4+/-8.0 ng/mL mean+/-SD, normal value<11 ng/mL), whereas the tryptase serum concentrations of all the 10 patients with HFP were within the normal range (8.1+/-1.8 ng/mL).Our data suggest that tryptase serum concentrations can discriminate between the allergic and HFP syndromes. As the tryptase half-life is 90-120 min, blood samples must be taken 1-2 h from the beginning of symptoms.Finding a biomarker could help physicians to formulate a correct diagnosis and thus in choosing the best therapeutic strategy. In this work, we analyzed the role of tryptase serum concentrations to differentiate real allergic syndromes from the HFP syndrome, which causes similar histamine-mediated effects by a different mechanism.