Conflicts of interest: H.T. has received educational grants from Novartis, AbbVie, LEO Pharma, MSD, Galderma Nordic, Pfizer, Meda, Janssen‐Cilag and Roche. K.T. has received educational grants from Boehringer, Novartis and Pfizer and honoraria from Novartis, Janssen‐Cilag, AbbVie, Lilly and Sanofi Genzyme for consulting and/or speaking. L.H. has received educational grants from Janssen‐Cilag, Novartis, AbbVie and LEO Pharma, honoraria from Novartis and UCB Pharma for consulting and/or speaking and is an investigator for AbbVie.