[1] Univ Oslo, Dept Paediat, Women & Childrens Div, Oslo Univ Hosp, NO-0407 Oslo, Norway
[2] Univ Oslo, Fac Med, NO-0407 Oslo, Norway
[3] Karolinska Inst, Dept Womens & Childrens Hlth, Stockholm, Sweden
[4] Royal Brompton Hosp, Dept Resp Paediat, London SW3 6LY, England
[5] Univ Gothenburg, Dept Paediat, Queen Silvia Childrens Hosp, Gothenburg, Sweden
[6] Salesi Childrens Hosp, Dept Paediat, Ancona, Italy
[7] Erasmus Univ, Med Center, Sophia Childrens Hosp, Dept Paediat, Rotterdam, Netherlands
[8] Univ Padua, Sch Med, Dept Paediat, Padua, Italy
[9] Univ Helsinki, Cent Hosp, Dept Allergy, Helsinki, Finland
[10] Charles Univ Prague, Fac Med 2, Prague, Czech Republic
[11] Univ Hosp Motol, Prague, Czech Republic
[12] Univ So Denmark, Dept Paediat, Kolding Hosp, Kolding, Denmark
[13] Univ Verona, Dept Paediat, I-37100 Verona, Italy
[14] Karolinska Inst, Inst Environm Med, Ctr Allergy Res, S-10401 Stockholm, Sweden