Treatment persistence in paediatric and adolescent psoriasis patients followed into young adulthood: from topical to systemic treatment - a prospective, longitudinal, observational cohort study of 448 patients.

BACKGROUND Although solely topical treatment often suffices, psoriasis patients 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. OBJECTIVES To determine median time from psoriasis onset until i) solely topical discontinuation and ii) switch to systemic treatment. Further, to identify patient characteristics associated with switching to systemic treatments. METHODS Data were extracted from the Child-CAPTURE registry, a prospective, observational cohort of paediatric-onset psoriasis patients followed into young adulthood from 2008 until 2018. Data prior to inclusion in registry were collected retrospectively. Median time was determined through Kaplan Meier survival analyses. Cox regression analysis was used to identify patient characteristics associated with switch to systemic treatment. RESULTS Of 448 patients, 62.3% stayed on solely topical treatment until data-lock; 14.3% switched from topical to phototherapy, but not to systemic treatment; and 23.4% switched to systemic treatment. Median time from psoriasis onset until i) solely topical discontinuation was 7.3 years and ii) switch to systemics was 10.8 years. Higher Psoriasis Area and Severity Index and a (Children's) Dermatology Life Quality Index >5 were independently associated with switching to systemic treatment. CONCLUSIONS In a population of paediatric and adolescent psoriasis patients with mild to severe psoriasis, a third needs more intensive treatment than solely topical therapy to control their disease. We consider median time until switch to systemic to be long.