Diagnosis of severe asthma according to the European Respiratory Society (ERS) and American Thoracic Society (ATS) definition, with and without nasal symptoms
normal pulmonary function post-therapy (FEV1 post-bronchodilation: greater than 80% of the predicted value, with FEV1/ vital capacity (VC) \> 88-89% - for males and females, respectively - of the predicted value)
non reversible chronic airflow limitation (FEV1 post-bronchodilation: lower than 70% of the predicted value, with FEV1/VC \< 88-89% of the predicted value)
Signing of the informed consent
You may not be if
Referred Pregnancy
Use of therapy with beta-blockers
Smoking (current or within the previous 3 months)
Negation to participate to the study
Current upper and lower airways infectious diseases
