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