Allergy as a systemic disease

The prevalence of allergic diseases has shown an increase in the last few years. Allergic diseases develop in persons with a genetic background, this genetic trait being known as atopy. The main pathophysiological characteristic of allergy is inflammation. The inflammatory process may explain the diversity of symptoms and signs of allergy. The early sensitization increases the risk of developing different symptomatic forms of allergy, and one person may present different symptoms and signs of allergy. But some persons can become allergic without atopy trait in conditions of a higher and longer exposure to allergens (e.g. occupational allergy). In the last years new allergens have induced symptoms, sometimes with a life-threatening evolution. The load of allergen in public areas is also increasing. In this context, allergy must be understood as a unique systemic disease with various forms of presentation.