1. Department of Clinical and Experimental Medicine, Postgraduate Training Program in Pediatrics, University of Catania, Catania, Italy
2. Pediatric Unit, Azienda di rilievo nazionale ARNAS “Garibaldi,” Catania, Italy
3. Pediatric General and Emergency Operative Unit, Cannizzaro Hospital, Catania, Italy
4. Department of Clinical and Experimental Medicine, University Hospital “Policlinico-San Marco,” Catania, Italy
5. Unit of Pediatrics and Pediatric Emergency, AOU “Policlinico,” PO “San Marco,” University of Catania, Catania, Italy