Mario Valenti has been a consultant and/or speaker for Sanofi, Leo Pharma, Eli Lilly, Novartis, Janssen, AbbVie, and Boehringer Ingelheim. Luciano Ibba has been a consultant for Almirall. Paolo Dapavo has been a speaker for Novartis, AbbVie, Sanofi, UCB, Janssen, Eli Lilly, and Leo Pharma. Piergiorgio Malagoli has been a speaker for AbbVie, Eli Lilly, Novartis, Janssen-Cilag, Celgene, Leo Pharma, and Almirall. Angelo V. Marzano reports consultancy/advisory board disease-relevant honoraria from AbbVie, Amgen, Boehringer-Ingelheim, Bristol Myers Squibb, Incyte, Leopharma, Novartis, Pfizer, Sanofi, and UCB. Francesco Loconsole served on advisory boards and/or received honoraria for lectures from Abbvie, Janssen-Cilag, Novartis, Lilly, and Sanofi. Martina Burlando has acted as a speaker and consultant for AbbVie, Janssen, Amgen, Novartis, Eli Lilly, and UCB Pharma. Anna Balato has served as consultant and/or has received fees from Abbvie, Almirall, Amgen, BI, BMS, Eli-Lilly, Janssen, Leo-Pharma, Novartis, Pfizer, Sanofi, and UCB. Matteo Megna acted as a speaker or consultant for AbbVie, Eli Lilly, Janssen, Leo Pharma, and Novartis. Giampiero Girolomoni has received personal fees from AbbVie, Almirall, Amgen, Boehringer-Ingelheim, Bristol-Myers Squibb, Eli-Lilly, Janssen-Cilag, Leo Pharma, Merck Serono, Novartis, Pfizer, Pierre Fabre, Samsung Bioepis, and Sanofi. Emanuele Trovato is involved in an intermittent project focused on consulting and/or advisory relationships and/or travel-congress support with Eli Lilly, Novartis, Janssen-Cilag, AbbVie, and Almirall. Claudia Lasagni declares a conflict of interest with AbbVie, Novartis, Eli Lilly, and Almirall. Claudio Guarneri has been a scientific consultant, speaker, and clinical study investigator for AbbVie, Celgene, Janssen, Eli Lilly, Novartis, Pfizer, Sanofi, Almirall, and Leo Pharma. Simone Ribero has served as an advisory board member and/or consultant and has received fees and speaker’s honoraria or has participated in clinical studies for AbbVie, Almirall, Leo Pharma, Eli Lilly, Novartis, Pfizer, and Sanofi Genzyme. Francesca M. Gaiani acted as a speaker or consultant for Novartis, AbbVie, Eli Lilly, Celgene, Leo Pharma, and Almirall. Carlo G. Carrera has served as a board participant or speaker for Abbvie, Lilly, Janssen, Novartis, Celgene, Almirall, and Leopharma. Emanuele C. Cozzani acted as a speaker or consultant for Abbvie, Almirall, Eli Lilly, Leo-Pharma, and Novartis. Andrea Sechi has received honoraria from Novartis, DS Laboratories, Cantabria Labs Difa Cooper, and Eli Lilly. Rossana Moroni has been a consultant for Almirall. Antonio Costanzo has served as an advisory board member, consultant, and has received fees and speaker’s honoraria or has participated in clinical trials for AbbVie, Almirall, Biogen, Leo Pharma, Eli Lilly, Janssen, Novartis, Pfizer, Sanofi Genzyme, and UCB Pharma. Alessandra Narcisi has served on advisory boards, received honoraria for lectures, and received research grants from Almirall, AbbVie, Leo Pharma, Celgene, Eli Lilly, Janssen, Novartis, Sanofi Genzyme, Amgen, and Boehringer Ingelheim. Sara Di Giulio, Valentina Dini, Massimo Travaglini, Nicola Zerbinati, Eugenia V. Di Brizzi, Alessandra Michelucci, Luca Potestio, Martina Maurelli, Martina Dragotto, Luca Mastorino, Eleonora Bongiovanni, and Francesco Messina have no conflicts of interest to declare. Mario Valenti is an Editorial Board Member of Dermatology and Therapy. Mario Valenti was not involved in the selection of peer reviewers for the manuscript nor any of the subsequent editorial decisions.

Institutional review board approval was exempted, as the study protocol did not deviate from standard clinical practice. All patients received guselkumab, as per good clinical practice, in accordance with European guidelines. All included patients had provided written consent for retrospective study of data collected during routine clinical practice (demographics and clinical scores). The study was performed in accordance with the Helsinki Declaration of 1964 and its later amendments. Data collection and handling complied with applicable laws, regulations, and guidance regarding patient protection, including patient privacy.