[1] Bispebjerg Hosp, Resp Res Unit, Copenhagen, Denmark
[2] Hvidovre Univ Hosp, Dept Resp Med, Copenhagen, Denmark
[3] Aarhus Univ Hosp, Dept Resp Dis & Allergy, Aarhus, Denmark
[4] Gentofte Univ Hosp, Allergy Clin, Copenhagen, Denmark
[5] Sygehus Lillebaelt, Dept Resp Med, Vejle, Denmark