1. University of Helsinki, Helsinki University Central Hospital, Respiratory Diseases and Allergology, Inflammation Center, Skin and Allergy Hospital, P.O. Box 160, 00029 Helsinki, Finland
2. Department of Industrial Engineering and Management, Aalto University, P.O. Box 15500, 00076 Aalto, Finland
3. South Karelia Allergy and Environment Institute, Lääkäritie 15, 55330 Tiuruniemi, Finland
4. Social Insurance Institution, Research Department, P.O. Box 450, 00101 Helsinki, Finland
5. University of Helsinki, Helsinki University Central Hospital, Pediatric Diseases and Allergology, Inflammation Center, Skin and Allergy Hospital, P.O. Box 160, 00029 Helsinki, Finland