THE EVOLUTION OF ALLERGIC DISEASES

The term ‘allergy’ and ‘allergic diseases’ have always been the focus of attention of the societies. The epidemic in allergy has been pronounced and witnessed within the last decades. The recent develop-ments in the fields of allergy and immunology have enabled superior illumination of the mechanisms and networks underlying allergic diseases, which in turn initiated and supported the development of innovative diagnostic methods. The definition of disease endotypes, phenotypes and also theratypes, development of engineered allergens and novel administration routes for allergen specific immunother-apy approaches are among the consequences. Novel treatment approaches developed with the light of these advancements, in addition to better understanding of the underlying mechanisms have nourished the steep escalation in the frequency of allergic diseases. On the other hand, these advancements were still short of explaining the causes underlying allergy epidemic. In recent years, environmental aware-ness has been increasing, which was also translated in to the field, and understanding the impact of environmental stressors, additional to genetic influence and allergen exposure, has led to a passion in the scientific community to investigate the relationship between allergic diseases and environmental aspects. In the last decades, the studies were based on various hypotheses and theories, such as ‘Old Friends’, ‘Biodiversity and Dysbiosis’ and ‘Hygiene Hypothesis’, and many valuable data was accu-mulated to describe the underlying causation of this awareness. The recently postulated ‘Epithelial Barrier Theory’ suggests that disrupters of the epithelial barriers lining the lungs, skin and gastroin-testinal system lead to loss of protective functions of these contact sites and trigger the production of epithelial alarmins. Altered microbiome biodiversity and the initiation of opportunistic pathogen colonization, which in collaboration with the immune system starts local and systemic inflammation. The amplification and movement of this inflammation to peripheral sites was reported to be causative in a number of inflammatory conditions including allergic diseases. Day by day, acquisition of a greater knowledge of the interference between the environment, the microbiome and the immune system can provide better knowledge about the development of allergic and many other chronic non-communica-ble diseases. This different line of vision together with increasing environmental awareness could be helpful in the limitation of allergic diseases.