1. Department of Otorhinolaryngology Cliniques Universitaires Saint‐Luc Brussels Belgium
2. Institute of Experimental and Clinical Research Pole of Pulmonology, Otorhinolaryngology and Dermatology UCLouvain Brussels Belgium
3. Clinical Division of Pediatrics University Hospitals Leuven Belgium
4. Allergy and Clinical Immunology Research Group Department of Microbiology, Immunology and Transplantation KU Leuven Belgium
5. Allergy Unit Hospital CUF Descobertas, Lisbon, Portugal Lisbon Portugal
6. Respiratory Rehabilitation and Respiratory Division University Hospitals Leuven, KU Leuven Leuven Belgium
7. Clinical Division of Ear, Nose and Throat Disease, Head and Neck Surgery University Hospitals Leuven Belgium
8. Department of Otorhinolaryngology Guy’s and St‐Thomas’ University Hospital London UK
9. Department of Ear, Nose and Throat Disease St‐George Hospital London UK