1. Haartman Institute University of Helsinki Helsinki Finland
2. Skin and Allergy Hospital University of Helsinki and Helsinki University Hospital Helsinki Finland
3. Department of Otolaryngology Yong Loo Lin School of Medicine National University of Singapore Singapore Singapore
4. Allergy Centre Tampere University Hospital Tampere Finland
5. Faculty of Social Sciences University of Tampere Tampere Finland
6. HUSLAB Helsinki University Hospital Helsinki Finland
7. Department of Public Health University of Helsinki Helsinki Finland
8. Department of Health Protection National Institute for Health and Welfare Kuopio Finland