In the last years the frequency of allergic diseases has markedly increased, the fact that leads to more people getting interested in this problem. Allergic diseases are in all age and could lead to a disease of any organ. Today each doctor meets an allergic patient in the surgery. Questions about aetiology, pathogenesis, prevention and treatment are the topics of many professional conversations, also in the conversation among parents of a child and a doctor. The reality is that allergic diseases always result from genetic interaction and influence of the environment. Any repeated hard breathing, hearing invention, and coughing should lead to a professional counselling, with right differentially diagnosed conclusion, if it is possible.