The aim of this retrospective, multicentre cohort study was to compare the safety, effectiveness, and drug survival of IL-17 and IL-23 inhibitors among 27 EP and 59 PP patients (36 with generalised pustular psoriasis [GPP] and 23 with palmoplantar pustular psoriasis [PPP]) attending two Italian tertiary referral centres (the Dermatology Clinic at the Turin University Hospital and the Dermatology Unit at Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico of Milan) between October 2019 and July 2022. The gene discussed is IL17A; the disease is palmoplantar pustulosis.