[1] Univ Murcia, Arrixaca Univ Childrens Hosp, Resp Unit, Murcia, Spain
[2] Univ Murcia, Arrixaca Univ Childrens Hosp, Allergy Unit, Murcia, Spain
[3] IMIB Res Inst, Murcia, Spain
[4] Asthma UK, London, England
[5] Great Ormond St Hosp Sick Children, Dept Paediat Resp Med, London, England
[6] UCL, Dept Resp Crit Care, Great Ormond St Inst Child Hlth, London, England
[7] UCL, Anaesthesia Unit, Great Ormond St Inst Child Hlth, London, England
[8] Univ Padua, Womens & Childrens Hlth Dept, Padua, Italy
[9] Marienhosp Wesel, Childrens Hosp, Wesel, Germany
[10] Marienhosp Wesel, Res Inst, Wesel, Germany
[11] Univ Liege, Dept Resp Med, Liege, Belgium
[12] Univ Autonoma Barcelona, Paediat Pulmonol Unit, Hosp Vall dHebron, Barcelona, Spain
[13] Univ Pisa, Dept Clin & Expt Med, Paediat Sect, Pisa, Italy
[14] Erasmus MC Sophia Childrens Hosp, Paediat Paediat Resp Med, Rotterdam, Netherlands
[15] Univ Athens, Sch Med, Dept Paediat, Attikon Gen Hosp, Athens, Greece
[16] Univ Hosp, Dept Paediat, Dusseldorf, Germany