1. Pediatric Unit, “Ospedali Riuniti”, University Hospital, Ancona, Italy
2. Department of Pediatrics, University of Verona, Verona, Italy
3. Department of Pediatrics, “San Matteo” Foundation IRCCS, University of Pavia, Pavia, Italy
4. Department of Allergy and Pulmonology, Pediatric Hospital “Giovanni XXIII”, University of Bari, Bari, Italy
5. Pediatric Clinic, Department of Pediatrics, University of Parma, Parma, Italy
6. Pediatric Unit, “San Giuseppe” Hospital, Empoli, Florence, Italy