**1. Introduction**

Allergic diseases have been considered a worldwide health problem. The incidence and prevalence of hypersensitivity/allergy conditions are increasing every day, affecting people of any age, damaging a broad range of organs, and making a diagnostic challenge for the clinician [1]. It is well known that an accurate diagnosis could affect the clinical outcome; this is particularly important for the treatment of allergic diseases because the identification of the causative antigen and other molecules associated with specific immunological activation by allergen-based tests allows personalized medicine and precision treatment [2].

© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2017 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
