Evolving Landscape of Psoriatic Arthritis in the Biologic Era for Psoriasis Patients

A recent cohort reports a psoriatic arthritis prevalence of 11.7% among patients with moderate-to-severe psoriasis — an updated estimate in the biologic/small-molecule era that recalibrates expectations for musculoskeletal disease in treated populations. Contemporary systemic therapy patterns and wider use of targeted agents likely explain this lower-than-expected rate and shift practical screening priorities in dermatology clinics. Current prevalence estimates are therefore shaped by treatment-era detection dynamics and should be interpreted in that context.

This retrospective, single-center cohort followed 308 patients in a dermatology department from July 2008 to January 2024, with primary endpoints of PsA prevalence and incident PsA during the observation window. The analysis incorporated contemporaneous therapy exposure, objective case ascertainment using CASPAR criteria with rheumatologist confirmation, and clinically meaningful follow-up from both psoriasis diagnosis and treatment initiation—elements that support the study’s internal validity.

The investigators also report an observational association between biologic/small-molecule exposure and subsequent PsA risk: the biologic/small-molecule group had a higher cumulative incidence than csDMARD-only or non-pharmacological groups. This is an association, not proof of causation. Broader and earlier use of targeted therapies could plausibly suppress subclinical synovitis or change pain reporting and functional complaints, lowering observed prevalence in some settings; conversely, treatment selection and intensified surveillance in biologic-treated patients may increase identification of symptomatic PsA. These competing effects—disease suppression, altered symptom expression, and surveillance bias—complicate simple prevalence interpretation and support adapting screening strategies to treatment exposure.

The study further identified non-therapy risk factors, most strongly nail involvement and obstructive sleep apnea (OSA), which were independently associated with PsA onset in multivariable models. Nail disease showed a robust positive association with later PsA, and OSA emerged as a high-odds correlate—findings consistent with multifactorial transition models linking cutaneous, mechanical, and systemic inflammatory pathways. These comorbid features can serve as practical screening flags to identify patients with psoriasis who warrant closer musculoskeletal assessment.