LAUSR

INTRODUCTION Psoriasis affects 0.5% of children in Europe, with moderate to severe clinical forms in 15-35% of cases warranting the use of systemic treatments. Few treatments are licensed for childhood psoriasis. In this study, we analyzed the frequency of such prescriptions. MATERIALS AND METHODS Our study was based on 3 retrospective cohort trials conducted in France between 2012 and 2018: χ-Psocar (313 children with psoriasis seen in hospitals), PsoLib (207 children seen in a private practice), and BiPe (134 children on biotherapies). Our evaluation was centered on off-label use. To avoid duplicates between cohorts, analysis focused on each cohort independently. RESULTS In the χ-Psocar study, in 34.8% of cases, use of at least one off-label treatment, mainly topical vitamin D (36.0%), and systemic treatments (methotrexate and cyclosporine) was noted, on account of either the clinical type of psoriasis (13.7%) or patient age (24.6%). In the PsoLib study, in 41.5% of cases, at least one off-label treatment was noted, mainly combined calcipotriol-betamethasone (24.2%), ciclopirox shampoo (7.2%) and systemic treatments (n=20). The main reason was patient age (41.5%). In the BiPe study, in 97.0% of cases, at least one off-label treatment was noted. These prescriptions mainly concerned a combination of calcipotriol-betamethasone (68.7%) and tacrolimus (11.2%) along with systemic treatment comprising methotrexate, cyclosporin, methoxsalen or apremilast (n=125), but also biotherapies (n=85). The biotherapies were used off-label since at that time they had not yet been granted marketing authorisation. DISCUSSION This study focused on 3 cohorts of children with psoriasis seen either in private practice or in a hospital setting, and it involved all types of treatment. Off-label prescriptions ranged from one-third to almost 100% of the children, depending on the individual cohorts. The prescribed drugs were topical treatments, conventional systemic drugs and biotherapies. Off-label prescription is not strictly prohibited in France provided it is within a well-defined regulatory framework. Where there is a rich bibliography, confident recommendations may be made. Unfortunately, in childhood psoriasis, the literature and recommendations are very limited, leaving prescribers with considerable individual responsibilities. Review of the license concerning children with psoriasis, a push to conduct therapeutic studies and the drafting of recommendations all appear necessary.