1. Department of Otorhinolaryngology, Head and Neck Surgery; Universitätsmedizin Mannheim; Medical Faculty Mannheim; Heidelberg University; Mannheim Germany
2. Center for Rhinology and Allergology Wiesbaden; Wiesbaden Germany
3. Allergy and Clinical Immunology Section; Hospital Sant Joan de Déu; Universitat de Barcelona; Barcelona Spain
4. Allergy Section; Department of Internal Medicine; Hospital Universitari Vall d'Hebron; Barcelona Spain
5. Children's Center Bethel, Protestant Hospital Bielefeld and Allergy Center; Ruhr-University; Bochum Germany
6. Medical Faculty; Institute of Medical Statistics, Informatics, and Epidemiology; University of Köln; Köln Germany
7. Allergy and Asthma Center Westend; Berlin Germany