Declaration of interests ML has received consulting fees or honoraria, or both for lectures from ALK, Allergopharma, AstraZeneca, Berlin-Chemie, Boehringer Ingelheim, Chiesi, GSK, HAL Allergy, Leti, Novartis, MSD, Sanofi, and TEVA; and grants for research or clinical trials, or both from Deutsche Forschungsgemeinschaft, AstraZeneca, and GSK. GGB has received honoraria for lectures from AstraZeneca, GSK, Boehringer Ingelheim, Novartis, Chiesi, and Sanofi. GWC has received consulting fees or honoraria, or both for lectures from AstraZeneca, Chiesi, Novartis, Sanofi, Menarini, Stallergenes Greer, GSK, and HAL Allergy. DJJ has received consulting fees or honoraria or both for lectures from AstraZeneca, GSK, and Sanofi; and grants for research from AstraZeneca. PN has received personal fees or grants, or both from AstraZeneca, TEVA, Sanofi, Equillium, Foresee, Arrowhead Pharma, Cyclomedica, and GSK. RB has received consulting fees or honoraria, or both for lectures from ALK, Allergopharma, AstraZeneca, Berlin-Chemie, Boehringer Ingelheim, Chiesi, Cipla, GSK, HAL Allergy, Leti, Novartis, Roche, Sanofi, and TEVA; and grants for research or clinical trials, or both from Boehringer Ingelheim, GSK, Novartis, and Roche. JCV has received consulting fees or honoraria, or both for lectures from AstraZeneca, Avontec, Bayer, Bencard, Bionorica, Boehringer Ingelheim, Chiesi, Genzyme, GSK, Janssen-Cilag, Leti, MEDA, Merck, MSD, Mundipharma, Novartis, Nycomed (Altana), Pfizer, Regeneron, Revotar, Sanofi, Sandoz-Hexal, Stallergens, TEVA, UCB/Schwarz-Pharma, and Cadila; and received grants for research or clinical trials, or both from Deutsche Forschungsgemeinschaft, GSK, and MSD.