1. Pediatric Unit, “Maggiore” Hospital, Crema, Department of Pediatrics, University of Pavia, Italy
2. Department of Pediatrics, “San Matteo” Foundation IRCCS, University of Pavia, Pavia, Italy
3. Unit of Respiratory Medicine, Department of Pediatrics, University of Florence, Anna Meyer University Hospital for Children, Florence, Italy
4. Allergy Unit, Department of Pediatrics, University of Messina, Messina, Italy
5. Pediatric Unit, “Ospedali Riuniti”, University Hospital, Ancona, Italy
6. Department of Pediatrics, University of Bologna, Bologna, Italy