Funding

No sources of funding were used to conduct this study or prepare this manuscript.

Conflict of interest

Tiago Torres declares the following conflicts of interest: AbbVie, Almirall, Amgen, Arena Pharmaceuticals, Biocad, Biogen, Boehringer Ingelheim, Bristol Myers Squibb, Celgene, Fresenius Kabi, Janssen, LEO Pharma, Eli Lilly, MSD, Mylan, Novartis, Pfizer, Samsung-Bioepis, Sanofi-Genzyme, Sandoz and UCB. Andrea Chiricozzi has served as advisory board member and consultant and has received fees and speaker’s honoraria or has participated in clinical trials for AbbVie, Almirall, Bristol Myers Squibb, Leo Pharma, Lilly, Janssen, Novartis, Pfizer and Sanofi Genzyme. Luís Puig has received consultancy and/or speaker’s honoraria from and/or participated in clinical trials sponsored from AbbVie, Almirall, Amgen, Baxalta, Biogen, Boehringer Ingelheim, Bristol Myers Squibb, Celgene, Fresenius-Kabi, Janssen, JS BIOCAD, LEO Pharma, Lilly, Mylan, Novartis, Pfizer, Regeneron, Roche, Sandoz, Samsung-Bioepis, Sanofi and UCB. Ana Maria Lé has no conflicts of interest. Angelo Valerio Marzano reports consultancy/advisory board disease-relevant honoraria from AbbVie, Boehringer Ingelheim, Novartis, Pfizer, Sanofi and UCB. Paolo Dapavo has no conflicts of interest. Esteban Dauden has the following conflicts of interest: advisory board member, consultant, grants, research support, participation in clinical trials, honorarium for speaking, and research support, in connection with the following pharmaceutical companies: Abbvie/Abbott, Almirall, Amgen-Celgene, Janssen-Cilag, Leo-Pharma, Novartis, Pfizer, MSD-Schering-Plough, Lilly, UCB, Brystol-Myers and Boehringer Ingelheim. José-Manuel Carrascosa acted as a consultant and/or speaker for and/or participated in clinical trials sponsored by Janssen Pharmaceuticals Inc., Eli-Lilly, AbbVie, Novartis, Amgen, Leo-Pharma, UCB, Boehringer Ingelheim, Almirall, Sandoz and Bristol Myers Squibb. Elizabeth Lazaridou has the following conflicts of interest: speaker's honoraria from and participation in clinical studies and advisory boards with Abbvie, Leo, Novartis, Pfizer, UCB, Sanofi, Janssen, Lilly-Galderma, Pierre Fabre, L'Oreala and Galenica. Gleison Duarte is/has served as a scientific consultant, speaker or clinical trial investigator for Abbvie, Bayer, Janssen, Leo‐Pharma, Galderma, Sanofi, Boehringer, Novartis, Pfizer and UCB. André V. E. de Carvalho: Dr Carvalho acted as a consultant and/or speaker for and/or participated in clinical trials sponsored by companies that manufacture drugs used for the treatment of psoriasis, including Janssen Pharmaceuticals Inc., Eli-Lilly, AbbVie, Novartis, Amgen, Leo-Pharma, UCB and Boehringer Ingelheim. Ricardo Romiti has received consulting fees from AbbVie, Boehringer Ingelheim, Bristol Myers Squibb, Eli Lilly, Galderma, Janssen, LEO Pharma, Novartis, Pfizer, Sanofi, and UCB Pharma; his institution has received research grants from AbbVie; and he has served as a paid speaker for AbbVie, Boehringer Ingelheim, Eli Lilly, Janssen, LEO Pharma, Novartis, Pfizer, Sanofi and UCB Pharma. Natalia Rompoti has received honoraria for lectures from Janssen, AbbVie, Genesis Pharma, Leo, Lilly Pharmaserve, Novartis and UCB, and support for scientific congress attendance from AbbVie, Janssen, Leo, Lilly Pharmaserve, Novartis and UCB. Laetitia Teixeira has no conflicts of interest to declare. Miguel Abreu has no conflicts of interest to declare. Elena Ippoliti has no conflicts of interest to declare. Carlo Alberto Maronese has no conflicts of interest to declare. Mar Llamas-Velasco has the following conflicts of interest: advisory board member, consultant, grants, research support, participation in clinical trials, honorarium for speaking, research support, in connection with the following pharmaceutical companies: Abbvie, Almirall, Amgen, Biogen, Celgene, Janssen-Cilag, Leo Pharma, Lilly, MSD, Novartis, Pfizer, UCB, Kyowa Kirin, Brystol-Myers and Boehringer Ingelheim. Eva Vilarrasa has received honoraria for acting as a consultant and/or speaker for AbbVie, Almirall, Boehringer, Celgene, Janssen, Leo Pharma, Eli Lilly, MSD, Novartis, Pfizer and UCB. Elena del Alcázar has participated as an Secondary investigator and/or invited speaker for AbbVie, Janssen, Novartis, Lilly, Leo Pharma, Almirall, Amgen, UCB and Sanofi. Athina‑Ioanna Daponte has no conflicts to declare. Marina Papoutsaki has received honoraria for advisory boards and lectures from Janssen, Leo Pharma, MSD, Genesis Pharma, Pfizer, Novartis, AbbVie and UCB, and support as an investigator in clinical studies from AbbVie, Novartis, Leo Pharma and Janssen. Andrea Carugno has no conflicts of interest. Francesco Bellinato has no conflicts of interest. Paolo Gisondi has received honoraria for acting as a consultant and/or speaker for AbbVie, Almirall, Amgen, Biogen, Bristol Myers Squibb, Celgene, Janssen, LEO Pharma, Eli Lilly, MSD, Novartis, Pierre Fabre, Sanofi and UCB.

Ethics approval

The present study was conducted in accordance with the Declaration of Helsinki (initially published in 1964) on Ethical Principles for Medical Research Involving Human Subjects. Ethical approval was waived in view of the retrospective nature of the study, and all the procedures being performed were part of the routine care.

Consent to participate

Not applicable.

Consent for publication

Not applicable.

Availability of data and materials

Data are available within the article or its supplementary materials.

Code availability

Not applicable.

Author contributions

TT and PG contributed to the study conception, design and statistical analyses; TT, AML, FB and PG contributed to manuscript writing. All authors contributed to data collection and interpretation of the data, provided critical feedback on the manuscript, approved the final manuscript for submission, and were accountable for the accuracy and integrity of the article.