1. Department of Health Sciences, University Magna Græcia of Catanzaro, Catanzaro, Italy
2. Respiratory Disease Unit, University Hospital of Catania, Catania, Italy
3. Allergy and Clinical Immunology Unit, A.O.U. Policlinico “G. Martino”, Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
4. Medicine of the Respiratory System, Hospital ‘P. Giaccone’, University of Palermo, Palermo, Italy
5. Allergology and Pulmonology Unit, Pta Biondo, ASP Palermo, Italy
6. Medical Department, Novartis Farma Origgio, Varese, Italy