ML reports grants for research or clinical trials, paid to his institution, from AstraZeneca, Deutsche Forschungsgemeinschaft (DFG), and GSK; and consulting fees, travel expenses, or honoraria for lectures from ALK, Allergopharma, AstraZeneca, Berlin-Chemie, Boehringer Ingelheim, Chiesi, GSK, HAL Allergy, Leti, Novartis, MSD, Sanofi, Stallergenes, and Teva. RB reports grants, paid to his institution, from Boehringer Ingelheim, GSK, Novartis, and Roche; speaker fees from AstraZeneca, Berlin-Chemie, Boehringer Ingelheim, Chiesi, Cipla, GSK, Novartis, Sanofi, Roche, and Teva; and payment for advisory board participation from AstraZeneca, Berlin-Chemie, Boehringer Ingelheim, Chiesi, Cipla, GSK, Novartis, Sanofi, Roche, and Teva. GWC reports research or clinical trial grants, paid to his institution, from Menarini, AstraZeneca, GSK, Sandi, and Genzyme; and personal fees for lectures and advisory board participation from Menarini, AstraZeneca, Chiesi, Faes Farma, Genentech, Guidotti-Malesci, GSK, HAL Allergy, Innovacaremed, Novartis, OM Pharma, Red Maple, Sanofi-Aventis, Sanofi-Genzyme, Stallergenes, and Uriach Pharma. CDR reports funding for travel and speaker fees from Novartis, Sanofi, GSK, TEVA, MSD, Almirall, AstraZeneca, Chiesi, Menarini, Stallergens, ALK-Abello, Allergy Therapeutics, HAL Allergy, Immunotek, and Royal. HN reports grants from GSK and personal fees from AstraZeneca, GSK, Kyorin Pharmaceutical, Novartis, and Sanofi; he is a scientific advisor for GSK. GGB reports personal fees for advisory board participation and lectures from AstraZeneca, Boehringer Ingelheim, Chiesi, GSK, Novartis, and Sanofi, outside of the submitted work. DJJ has received an investigator-initiated research grant from AstraZeneca and reports fees for advisory board participation and lectures from AstraZeneca, Sanofi, and GSK. In the past 5 years, IDP has received honoraria for speaking at sponsored meetings from AstraZeneca, Aerocrine, Chiesi, Sanofi/Regeneron, Menarini, and GSK; payments for organising educational events from AstraZeneca, GSK, Sanofi/Regeneron, and Teva; honoraria for advisory panel participation from Genentech, Sanofi/Regeneron, AstraZeneca, Boehringer Ingelheim, GSK, Novartis, Teva, Merck, Circassia, Chiesi, and Knopp; and sponsorship to attend international scientific meetings from GSK, AstraZeneca, Teva, and Chiesi. SK reports consulting fees and speaker fees from AstraZeneca, GSK, Chiesi, Sanofi, and Novartis. KM reports consulting fees and speaker frees from AstraZeneca, GSK, and Sanofi; and speaker fees from Chiesi and Novartis. JCV reports research grants from DFG, Land Mecklenburg-Vorpommern, GSK, and MSD; he has given independent lectures for and received honoraria from AstraZeneca, Avontec, Bayer, Bencard, Bionorica, Boehringer Ingelheim, Chiesi, Essex/Schering-Plough, GSK, Janssen-Cilag, Lupin, Leti, MEDA, Merck, MSD, Mundipharma, Novartis, Nycomed/Altana, Pfizer, Regeneron, Revotar, Sandoz-Hexal, Sanofi-Aventis, Stallergens, TEVA, UCB/Schwarz-Pharma, and Zydus/Cadila; and participated on advisory boards and provided independent advice for AstraZeneca, Avontec, Bayer, Bencard, Boehringer Ingelheim, Chiesi, Essex/Schering-Plough, GSK, Janssen-Cilag, MEDA, MSD, Mundipharma, Novartis, Regeneron, Revotar, Roche, Sanofi-Aventis, Sandoz-Hexal, TEVA, and UCB/Schwarz-Pharma. CT declares no competing interests.