The role of phototherapy in reducing the risk of psoriatic arthritis among psoriasis patients in the era of biologics.

BACKGROUND AND

OBJECTIVES

Biologic therapies for psoriasis have shown promise in reducing the risk of Psoriatic Arthritis (PsA) by targeting inflammatory pathways. Emerging evidence suggests that phototherapy may also exert systemic anti-inflammatory effects. This study examines the impact of phototherapy on the progression to PsA.

PATIENTS AND

METHODS

This exploratory, hypothesis generating retrospective cohort study comprised 667 psoriatic patients, subclassified based on therapeutic interventions administered during longitudinal follow-up: phototherapy alone; phototherapy combined with systemic therapy [either conventional agents (e.g., methotrexate, acitretin, cyclosporine) or biologics (e.g., TNF inhibitors, anti-IL-12/23, anti-IL-17A, anti-IL-23A); topical therapy alone; and systemic monotherapy. PsA diagnoses were established in accordance with the Classification Criteria for Psoriatic Arthritis.

RESULTS

Patients receiving standalone phototherapy exhibited a reduced PsA incidence compared to those on topical agents (4.09 vs 5.30 events per 100 person-years; HR = 0.73; 95 % CI: 0.53-0.99; p = 0.047). Combining phototherapy with systemic therapy further reduced PsA risk compared to systemic monotherapy (2.26 vs 3.74 events per 100 person-years; HR = 0.56; 95 % CI: 0.38-0.82; p = 0.003). The lowest incidence was observed in patients treated with both phototherapy and biologics, outperforming biologics alone (HR = 0.43; 95 % CI: 0.19-0.93; p = 0.03).

CONCLUSIONS

Phototherapy, especially in combination with systemic treatments, demonstrates synergistic potential in mitigating PsA risk.