The diagnosis of allergy has experienced a great progress during the last years. The aetiological diagnosis of allergy is based on skin prick tests and in vitro specific-IgE tests. However, until a few years ago, we only were able to identify by these methods the allergenic sources (pollens, epithelia, house dust mites, foods,...).
Nevertheless the allergenic sources have many different proteins, but commonly only a few of them are able to induce allergic reactions. The identification of these allergenic proteins and the improvement of techniques for obtaining relevant quantities of recombinant allergens, have permitted to develop in vitro and in vivo products able to identify these specific allergenic proteins, beyond the mere identification of the allergenic source.
This has meant the possibility to discover the proteins responsible for phenomena of cross-reactivity, to distinguish between true and false polysensitized patients, to uncover new allergenic proteins able to explain so far unexplainable reactions, to identify major and minor allergens, to predict the possibility to have an allergic reaction and the severity of it, to foresee the probability to overcome an allergic disease, to improve the composition and the prescription of specific immunotherapy, etc.