Receiver operating characteristic (ROC) curves and corresponding areas under the curve (AUC) with 95% CI (0.95) for tryptase and histamine testing for allergy. Sensitivity = percentage of patients with mediator concentrations exceeding the threshold among patients with proved allergic shock (true positives); (1-specificity) = percentage of patients with mediator concentrations exceeding the threshold among patients with shock unrelated to allergy (false positives).