Occupational Respiratory Allergies and Gene-environment Interactions

The purpose is to compare clinical, functional, professional and socio-economical characteristics of patients with occupational asthma and work aggravated asthma. Secondary purposes are: * to evaluate diagnostic value of new non-invasive techniques such as exhaled nitric oxide and cytology of induced expectoration; * to estimate medical-social becoming of diagnosed work-related asthma after one year; * to establish a biobank of blood samples of individuals with work related asthma for measurement of cytokines and search for genetic polymorphisms associated with asthma.