Although solely topical treatment often suffices, patients with psoriasis may require more intensive treatment (phototherapy and/or systemic treatments) to control their disease. However, in paediatric, adolescent and young adult patients, little is known about persistence of topical treatment and time until switch to systemic treatment. To determine the median time from psoriasis onset until (i) discontinuation of solely topical agents and (ii) switch to systemic treatment, and to identify patient characteristics associated with switching to systemic treatments. Data were extracted from the Child-CAPTURE registry, a prospective, observational cohort of patients with paediatric-onset psoriasis followed into young adulthood from 2008 to 2018. Data prior to inclusion in the registry were collected retrospectively. Median times were determined through Kaplan-Meier survival analyses. Cox regression analysis was used to identify patient characteristics associated with switch to systemic treatment. Of 448 patients, 62·3% stayed on solely topical treatment until data lock; 14·3% switched from topicals to phototherapy, but not to systemic treatment; and 23·4% switched to systemic treatment. The median time from psoriasis onset until discontinuation of solely topical treatment was 7·3 years, and until switch to systemics was 10·8 years. Higher Psoriasis Area and Severity Index and (Children's) Dermatology Life Quality Index > 5 were independently associated with switching to systemic treatment. In a population of paediatric and adolescent patients with mild-to-severe psoriasis, one-third needed more intensive treatment than solely topical therapy to control their disease. We consider the median time until switching to systemics to be long. © 2020 The Authors. British Journal of Dermatology published by John Wiley & Sons Ltd on behalf of British Association of Dermatologists.