1 Pediatrics Department and Pediatric Allergy Unit, Sandro Pertini Hospital, Rome, Italy.
2 Pediatrics Department, Unit of Allergy and Immunology in Evolutive Age, Department of Clinical and Experimental Medicine, University of Parma, Parma, Italy.
3 Pediatrics Unit, Department for Mother and Child, Ramazzini Hospital, Carpi, Italy.
4 Allergology Service, San Carlo Clinic, Paderno Dugnano, Milan, Italy.
5 Department of Pediatric Pneumology and Immunology, Charité Medical University, Berlin, Germany. Electronic address: paolo.matricardi@charite.de.