1. Department of Internal Medicine, University of Genova and IRCCS Ospedale Policlinico San Martino, 16132 Genova, Italy
2. School and Operative Unit of Allergy and Clinical Immunology, Department of Clinical and Experimental Medicine, University of Messina, 98125 Messina, Italy
3. Internal Medicine Department, San Paolo Hospital, 17100 Savona, Italy