The aim of this paper is to provide an alternative and more efficient screening test for allergy with respect to traditional UNICAP and prick skin tests, which are commercially available nowadays. The proposed test is aimed at monitoring the interaction of the IgE protein with the allergen in an allergic subject. The idea relies on the fact that the interaction between the IgE and the corresponding allergen happens through binding mechanisms between the IgE and the allergen structure, changing the ionic content of the serum. This latter can be monitored by impedance measurements and confirmed by reactive oxygen species (ROS) evaluation in leukocyte subpopulations. Therefore, in this paper we propose a novel system for the detection of allergies based on impedance measurements and confirmed by ROS measurements. This type of measurement approach has never been presented in the literature for this purpose. A measurement protocol has been developed to guarantee reproducibility and repeatability of the assay. This paper describes both the instrument-specifically designed for impedance evaluation- and the measurement protocols for both methodologies, defining univocally, in this way, the overall measurement technique.