SERUM TRYPTASE AND URINARY 1-METHYLHISTAMINE AS PARAMETERS FOR MONITORING ORAL FOOD CHALLENGES IN CHILDREN

To study the usefulness of urinary 1-methylhistamine and serum tryptas e concentration as monitoring parameters in clinical settings, we inve stigated 32 children with atopic dermatitis and suspected food allergy during oral food challenges with eggs and cow's milk. Urinary 1-methy lhistamine (MH) excretion increased significantly within 1 h after pos itive oral food challenges (p<0.006), but showed considerable variatio n in negative challenges. MH seems to be a sensitive parameter (92.8%) , but its specifity is insufficient (37.7%). In the group of 16 positi ve oral. food challenges serum tryptase concentration increased signif icantly (p<0.02) directly after provocation and remained elevated up t o 2 h after provocation. No variation was observed in negative challen ges or nonatopic controls. Serum tryptase concentration seems to be sp ecific for marked clinical reactions after oral food challenges (100%) , but its sensitivity was low (25%) and not superior to evaluation by clinical means. We conclude that, despite positive results for the gro up of children, MH and serum tryptase concentrations are not useful pa rameters for monitoring oral food challenges in an individual child du e to insufficient sensitivity and specificity.