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. Department of Allergy and Pulmonology, Pediatric Hospital “Giovanni XXIII”, University of Bari, Bari, Italy
4. Department of Pediatrics, Sapienza University of Rome, Roma, Italy
5. Allergy Unit, Department of Pediatrics, University of Messina, Messina, Italy
6. Department of Pediatrics, University of Verona, Verona, Italy