This guideline covers assessing and managing psoriasis in adults, young people and children. It aims to improve long-term disease control and quality of life for people with psoriasis. NICE has produced a COVID-19 rapid guideline on dermatological conditions treated with drugs affecting the immune response. It recommends changes to usual practice to maximise the safety of patients and protect staff from infection during the COVID-19 pandemic. In September 2017, we revised the guideline throughout to link to other NICE guidance (including technology appraisals) and some relevant non-NICE guidelines, as well as including new MHRA safety advice and updated licensing information.