1. Department of Dermatology and Allergy, Charité Universitätsmedizin‐Berlin, Berlin, Germany
2. Department of Otorhinolaryngology, University Hospital, Ghent, Belgium
3. Allergy Centre, University Hospital, Odense, Denmark
4. Consiglio Nazionale delle Ricerche, Rome, Italy
5. University Hospital, Montpellier, France
6. Consiglio Nazionale delle Ricerche, Palermo, Italy
7. Imperial College for Science, Technology and Medicine, London, UK
8. University of Genoa, Genoa, Italy
9. Department of Dermatology and Allergy Biederstein and Division of Environmental Dermatology and Allergy Helmholtz Center, Technical University, Technische Universität, Munich, Germany
10. Department of Respiratory Medicine, Royal Brompton Hospital, London, UK
11. Academic Medical Centre, Department of Otorhinolaryngology, Amsterdam, the Netherlands
12. Allergy Department, 2nd Pediatric Clinic, National and Kapodistrian University, Athens, Greece
13. Skin and Allergy Hospital, University Central Hospital, Helsinki, Finland
14. Department of Clinical Immunology and Allergy, Medical University of Lodz, Lodz, Poland
15. Semmelweis Medical University, Budapest, Hungary
16. Department of Dermatology, Medical University of Vienna, Vienna, Austria
17. Coimbra University, Coimbra, Portugal
18. Ludwig Maximilians University, Munich, Germany
19. Children’s University Hospital, Zurich, Switzerland