Immunoglobulin E (IgE)-mediated allergic conditions are increasing worldwide. They affect the quality of life of millions of individuals, causing enormous costs for society. In her paper, Mariana Lloyd of Pathcare.org discusses the considerable advances made in the development of in vitro allergy testing since the discovery of the IgE antibody in 1967. Information obtained from component resolved diagnostic (CRD) allergy tests enable the clinician to provide the patient with specific information regarding cross-reactivity, prognosis, risks and severity of reactions, effects of specific and patient=individualised allergen avoidance measures, dietary advice and prophylactic an therapeutic treatments.