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.

Participants with work related asthma or suspected work related asthma will obtain a precise diagnosis concerning severity and control of respiratory disorder and also the possible effect of professional environment on the disorder. Their medical care and medico-legal care, in case of recognition of occupational disease, could be ameliorated.

In general, this study will allow the harmonization of diagnostic care and medical, medico-professional and medico-legal management of cases of work related asthma in specialized hospitals.

Inclusion Criteria:

- Patient consulting for suspected work-related asthma in one of hospitals participating to the study

Exclusion Criteria:

• Patient refusing to participate
• Pregnant or breastfeeding women
• Individual in life-threatening emergency
• Hospitalized patient
• Patient in a health or social institution
• Person deprived of liberty
• Person with total occupational disability
• Retired person
• Person diagnosed as non-asthmatic
• Asthmatic person already enrolled in a clinical trial of bio-therapy to treat asthma

Men or women, professionally active, consulting in one of hospitals participating to the study for suspicion of work-related asthma .