Acknowledgements
S. Ferrucci and F. Barei, have contributed equally to the conception, realization and writing the paper and both qualify as first author; A.V. Marzano, L. Naldi and E. Pezzolo have revised the manuscript; F. Barei did the statistical analysis. This is a retrospective study, so no ethics committee approval was needed. The patients in this manuscript have given written informed consent to publication of their case details.
Disclosure statement
S. Ferrucci is principal investigator in clinical trial to Amgen, Sanofi, Novartis, Lilly, Leo Pharma, Abbvie and she is advisory board or speaker to Novartis, Menarini, Sanofi, Abbvie and Leo Pharma. The other authors declare that there is no conflict of interest. E.Pezzolo has been consultant and speaker for Sanofi Genzyme, LEO Pharma, Novartis, AbbVie, Almirall, Janssen, Galderma, and Boehringer-Ingelheim. L.Naldi has been consultant and speaker for AbbVie, Almirall, Bristol Myers Squibb, Janssen, LEO Pharma, Novartis and Sanofi Genzyme.