Allergic diseases are among the top chronic diseases in Europe and developing countries, and the World Health Organisation now considers allergy a 'non-communicable, out-of-control disease' with a possible increase in prevalence of up to 50% in the latest generation. Allergology transversally involves different medical specialities, affecting different organs and apparatuses and opening up to numerous varieties of clinical pictures. In parallel, the Allergy Diagnostic Laboratory is assuming a major role in helping to provide a personalised, targeted and accurate approach for the allergic patient, based on the preliminary detection of an individual sensitisation profile. The aim of this document is to illustrate the whole range of new resources that Laboratory Medicine can provide for initial diagnostic guidance for Allergy, directing selected patients into the appropriate pathway, and referring those who really need an accurate specialist examination to the allergist. In a following document (part 2), specific allergies will be considered: food allergies, allergies to hymenoptera venoms and professional allergies (i.e. latex). [ABSTRACT FROM AUTHOR]