[1] Erasmus MC Sophia Childrens Hosp, Dept Paediat Paediat Resp Med, Rotterdam, Netherlands
[2] Univ Padua, Womens & Childrens Hlth Dept, Unit Resp Med & Allergy, Padua, Italy
[3] Isala Hosp, Dept Paediat, Princess Amalia Childrens Ctr, Zwolle, Netherlands
[4] Univ Groningen, Univ Med Ctr Groningen, UMCG Postgrad Sch Med, NL-9713 AV Groningen, Netherlands
[5] Univ Oslo, Inst Clin Med, Dept Paediat, Oslo, Norway
[6] Oslo Univ Hosp, Oslo, Norway
[7] Med Univ Graz, Dept Paediat & Adolescence Med, Resp & Allerg Dis Div, Graz, Austria
[8] Wilhelminenspital Stadt Wien, Dept Paediat & Paediat Surg, Vienna, Austria
[9] Karolinska Inst, Dept Womens & Childrens Hlth, Stockholm, Sweden
[10] Karolinska Inst, Ctr Allergy Res, Stockholm, Sweden
[11] Astrid Lindgren Childrens Hosp, Stockholm, Sweden
[12] Univ Leicester, Leicestershire Partnership Trust, Leicester, Leics, England
[13] Univ Leicester, Dept Infect Immun & Inflammat, Leicester, Leics, England
[14] Univ Hosp Gottingen, Div Pediat Resp Med, Dept Paediat Cardiol & Intens Care Med, Gottingen, Germany
[15] Helsinki Univ Hosp, Skin & Allergy Hosp, Helsinki, Finland
[16] Univ Crete, Univ Hosp Heraklion, Dept Paediat, Iraklion, Greece
[17] Univ Childrens Hosp Zurich, Div Resp Med, Zurich, Switzerland
[18] Univ Oxford, Dept Resp Med, Oxford, England
[19] Univ Verona, Dept Life & Reprod Sci, Paediat Sect, I-37100 Verona, Italy
[20] Univ Aberdeen, Div Appl Hlth Sci, Dept Primary Care Resp Med, Acad Primary Care, Aberdeen, Scotland
[21] Univ Groningen, Univ Med Ctr Groningen, GRIAC Res Inst, Dept Pediat Pulmonol & Allergol, Groningen, Netherlands
[22] Univ London Imperial Coll Sci Technol & Med, Natl Heart & Lung Inst, Leukocyte Biol & Resp Paediat, London, England
[23] Univ Queensland, Queensland Childrens Med Res Inst, Brisbane, Qld, Australia
[24] Childrens Hosp Colorado, Denver, CO USA
[25] Univ Colorado, Denver Sch Med, Denver, CO 80202 USA
[26] Univ Bern, Inst Social & Prevent Med, Bern, Switzerland
[27] Univ Aberdeen, Dept Paediat, Aberdeen, Scotland
[28] Royal Alexandra Childrens Hosp, Brighton, E Sussex, England
[29] Oslo Univ Hosp, Women & Childrens Div, Dept Paediat, Oslo, Norway
[30] Univ Oslo, Fac Med, Dept Paediat, Oslo, Norway