1. Haartman Institute, University of Helsinki, Helsinki, Finland;
2. Department of Otorhinolaryngology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland;
3. Department of Otorhinolaryngology, Päijät-Häme Central Hospital, Lahti, Finland;
4. Department of Otorhinolaryngology, University of Tampere, Tampere, Finland;
5. Terveystalo Healthcare OYJ of Finland, Finland;
6. Department of Otorhinolaryngology, Oslo University Hospital, Rikshospitalet, Oslo, Norway;
7. School of Health Sciences, University of Tampere, Tampere, Finland;
8. Department of Allergy, University of Helsinki and Helsinki University Hospital, Helsinki, Finland