There is no doubt today, that allergic diseases of the airways have a considerable genetic background. However it is also evident, that extrinsic factors are more or less responsible for the manifestation of these diseases. Epidemiological studies are an important tool to develop programs for effective prevention measurements. This is necessary to decrease the morbidity and with that also mortality. In principle allergic airway diseases have a very good prognostic outlook, since our present symptomatic therapy as well as the specific immunotherapy are very effective in treating these patients. Another aspect, which has to be considered, is the social economical factor, which signals, that increased mortality is to a great extend dependent on medical judgement and appropriate treatment, especially in the poorer patient population. Another reason for the increased mortality might be the inadequate education of therapists to deal with this type of disease.