From Psoriasis to Psoriatic Arthritis: Decoding the Impact of Treatment Modalities on the Prevention of Psoriatic Arthritis

Introduction: Biologic therapies are licensed for both psoriasis (PsO) and psoriatic arthritis (PsA) with some electronic medical record data suggest that IL (Interleukin)-23 blockers might be more protective in PsA prevention than TNF blockers; however, the findings have been inconsistent. Higher Psoriasis Area and Severity Index (PASI) scores have also been linked to an increased PsA risk. To clarify these unresolved issues we investigated biologic agents, methotrexate, phototherapy, and topical therapy for PsA prevention in patients with psoriasis. Methods: This retrospective cohort study analyzed data from 58,671 patients with psoriasis from the Israeli Meuhedet Health Services Organization database was evaluated for incident PsA. Patients were categorized on the basis of treatment: group 1, topical therapy; group 2, phototherapy; group 3, conventional disease-modifying antirheumatic drugs (cDMARDs; methotrexate); group 4, biologic DMARDs which was also stratified according to biologic class. Results: The PsA incidence rate was lower in the biologic agents’ group versus the methotrexate group (HR 0.46 [95% CI 0.35–0.62]). The incidence rates per 100 person-years varied across biologic treatment groups, with the anti‑IL‑12/23 or anti‑IL‑23p19 group at 4.57, the anti-IL-17 group at 4.35, and the TNF inhibitor group at 2.55. No differences were found between various biological agents in terms of preventing PsA. The phototherapy group exhibited a higher PsA development rate than the topical therapy group (HR 1.85 [95% CI 1.65–2.07]). Conclusion: Biological agents are more effective than methotrexate in reducing incident PsA in patients with psoriasis. This lower rate of PsA on topical therapy compared to phototherapy supports the importance of psoriasis severity as a risk factor.