1. Pulmonology Unit, S. Valentino Hospital, Treviso, Italy
2. Allergy and Pneumology Outpatient Clinic, Ancona, Italy
3. Allergy and Pneumology Outpatient Clinic, Bergamo, Italy
4. Respiratory Unit, ASST Papa Giovanni XXIII Hospital, Bergamo, Italy
5. Department of Health Sciences, University of Milan, Bergamo, Italy