1. Department of Medicine, University of Verona, 37134 Verona, Italy
2. Unit of Epidemiology and Medical Statistics, Department of Diagnostics and Public Health, University of Verona, 37134 Verona, Italy
3. Department of Cardiac Thoracic Vascular Sciences and Public Health, University of Padova, 35129 Padua, Italy
4. Allergy and Respiratory Diseases, Department of Internal Medicine (DIMI), University of Genoa, 16132 Genoa, Italy
5. Division of Respiratory Diseases, Department of Medical and Surgical Sciences, Respiratory and Critical Care Unit, University of Bari, Polyclinic University Hospital, 70124 Bari, Italy
6. Department of Health Sciences, University “Magna Græcia” of Catanzaro, 88100 Catanzaro, Italy
7. Allergy Unit and Asthma Center, Verona University Hospital, 37134 Verona, Italy