1 Pediatric Unit, Department of Medical and Surgical Sciences, University of Bologna, Bologna, Italy; Pediatric Unit, Ramazzini Hospital, Carpi, Italy. Electronic address: arianna.dondi@gmail.com.
2 Pediatric Unit, Department of Medical and Surgical Sciences, University of Bologna, Bologna, Italy.
3 Department of Paediatric Pneumology and Immunology, Charité Medical School, Berlin, Germany.