1. Department of Pediatric Pneumology and Immunology; Charité Medical University; Berlin Germany
2. Pediatric Unit; Department of Medical and Surgical Sciences; University of Bologna; Bologna Italy
3. Pediatric Clinic of Medicine and Surgery; University of Parma; Parma Italy
4. Pediatric Department and Pediatric Allergology Unit; Sandro Pertini Hospital; Rome Italy
5. Biostatistics; L'Altra Statistica srl, Consultancy & Training; Rome Italy
6. Allergology Service; San Carlo Clinic; Paderno Dugnano; Milan Italy
7. Pediatric Emergency Unit; S. Orsola-Malpighi Hospital; Bologna Italy
8. Pediatric Unit; San Camillo Forlanini Hospital; Rome Italy
9. Dipartimento della Donna, del Bambino e di Chirurgia Generale e Specialistica; Università della Campania Luigi Vanvitelli; Naples Italy
10. Pediatric Department; La Sapienza University; Rome Italy
11. Pediatric Unit; Fatebenefratelli Hospital; Benevento Italy
12. Pediatric Highly Intensive Care Unit; Department of Pathophysiology and Transplantation; Università degli Studi di Milano; Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico; Milan Italy
13. Pediatric Intermediate Care Unit; Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico; Milan Italy
14. Pediatric Section; Department of Life and Reproduction Sciences; University of Verona; Verona Italy
15. Pediatric Allergology and Immunology Unit; Policlinico Tor Vergata; University of Rome Tor Vergata; Rome Italy
16. Pediatric Unit; San Giuseppe Hospital; Empoli Italy
17. Pediatric Unit; Grassi Hospital; Rome Italy
18. Pediatric Unit; Santa Barbara Hospital; Iglesias Italy
19. Pulmonary Disease and Allergy Unit; G. Gaslini Hospital; Genoa Italy
20. Pediatric Unit; Crotone Italy
21. Primary Care Pediatrics; ASL Salerno; Vietri sul Mare Italy
22. Department of Laboratory Medicine; University Hospital of Padua; Padua Italy