Understanding the transition from psoriasis to psoriatic arthritis: the role of targeted therapy.

Most individuals who develop psoriatic arthritis (PsA) first present with psoriasis (PsC), often years before musculoskeletal symptoms emerge. Progression from PsC to PsA is multifactorial, shaped by genetic and environmental influences, and may involve at-risk stages and subclinical stages before culminating in clinically overt arthritis. Consistently identified risk factors include greater PsC severity, nail involvement, arthralgia, and elevated body mass index. In this Viewpoint, we review and critically appraise current evidence on PsC-to-PsA transition, focusing on how the mechanism of action of biologic disease-modifying antirheumatic drugs may influence this trajectory. Emerging data suggest that therapies targeting the interleukin (IL)-23/IL-17 axis may provide greater protection against PsA development than tumour necrosis factor inhibitors, underscoring the central role of this pathway in psoriatic disease pathogenesis. However, existing studies are limited by confounding, protopathic bias, and heterogeneous cohorts. By integrating mechanistic insights with clinical data, we emphasise the urgent need for rigorously designed multinational randomised controlled trials to determine whether, and how, biologic therapy can modify the natural history of psoriatic disease.