Conflicts of interest: S. Durham reports nonfinancial support from ALK and personal fees from ALK, Stallergenes Greer, Revelo, and ANGANY, Inc, outside the submitted work. O. Pfaar reports grants and/or personal fees from ALK-Abelló, Altamira, Allergopharma, Stallergenes Greer, HAL Allergy Holding B.V./HAL Allergie, AAAAI, Bencard Allergie/Allergy Therapeutics, Lofarma, Biomay, Circassia, ASIT Biotech Tools S.A., Dänisches Konsultat, Laboratorios LETI/LETI Pharma, MEDA Pharma/MYLAN, Anergis S.A., Mobile Chamber Experts, Indoor Biotechnologies, GlaxoSmithKline, Astellas Pharma Global, EUFOREA, ROXALL, Novartis, Sanofi-Aventis and Sanofi-Genzyme, Med Update Europe, streamedup!, Pohl-Boskamp, Inmunotek S.L., Wiley and Sons, Paul-Martini-Stiftung, Regeneron Pharmaceuticals, RG Aerztefortbildung, Firma Meinhardt, PneumoLIVE, Institut für Disease Management, Deutsche Forschungsgesellschaft, Springer, Thieme, AstraZeneca, Deutsche Allergie-Liga, AeDA, IQVIA Commercial, Ingress Health, Wort&Bild Verlag, Verlag ME, Procter&Gamble, and Alfried-Krupp Krankenhaus, all outside the submitted work; is member of EAACI Excom, member of Executive Board of Directors DGAKI; and coordinator or main or coauthor of different position papers and guidelines in rhinology, allergology, and allergen-immunotherapy. R. Pawankar reports no conflicts of interest. K. Spriggs reports grants and/or personal fees from ALK, AstraZeneca, Novartis, Sanofi-Genzyme, Seqirus, and Stallergenes Greer, all outside the submitted work.