Background: Psoriasis is a chronic inflammatory skin disorder that often precedes psoriatic arthritis. Conflicting evidence exists regarding whether biologic therapies for psoriasis can prevent or delay psoriatic arthritis onset.
Objectives: To determine whether biologic therapy for psoriasis is associated with a reduced incidence of psoriatic arthritis.
Methods: A retrospective cohort study was performed utilizing Optum's de-identified Clinformatics® Data Mart Database, from January 1, 2007, to February 29, 2024. Patients with moderate-to-severe psoriasis were identified by phototherapy use. Among these, some continued on phototherapy, and others switched to a biologic. Individuals with a psoriatic arthritis diagnosis or history of biologic therapy prior to phototherapy initiation were excluded. Cases of psoriatic arthritis developing within 1 year after biologic initiation were also excluded to minimize protopathic bias. Outcomes included the incidence of psoriatic arthritis, measured as incident cases per 1000 person-years. Hazard ratios (HRs) for psoriatic arthritis development were calculated using a multivariable Cox proportional hazards model.
Results: Of 36,508 patients who received phototherapy for psoriasis, 26,470 met eligibility criteria. Among these, 2611 patients switched to biologics, while 23,859 patients did not. The overall PsA incidence rate was 7.85 per 1000 person-years. Patients continuing phototherapy alone had an incidence rate of 8.06 per 1000 person-years, compared with 6.75 in the biologic cohort. After multivariable adjustment for demographics, comorbidities, insurance type and oral systemic therapy, biologic use was associated with a lower likelihood of psoriatic arthritis development compared with phototherapy (adjusted HR, 0.66; 95% CI, 0.53-0.83; p < 0.05).
Conclusions: In this study of moderate-to-severe psoriasis patients, those who initiated biologic therapy demonstrated a lower incidence of psoriatic arthritis than those continuing on phototherapy alone. This suggests that biologic treatments may delay or prevent psoriatic arthritis in psoriasis patients.
Keywords: biologics; phototherapy; prevention; psoriasis; psoriatic arthritis.
Psoriasis is a chronic inflammatory skin disease that affects about 3% of people in the United States and over 60 million people worldwide. It causes red, scaly patches on the skin and can significantly affect quality of life. Up to one in three people with psoriasis may later develop psoriatic arthritis, a painful joint condition that can lead to lasting disability. Preventing or delaying psoriatic arthritis (PsA) is therefore an important goal in psoriasis care. Using a large nationwide U.S. health insurance database, we identified 26,542 adults with moderate‐to‐severe psoriasis who initially received phototherapy but with no prior diagnosis of PsA or biologic therapy. We then compared those who later began biologic therapy with those who continued phototherapy only. Over time, patients treated with biologic therapy were less likely to develop psoriatic arthritis than those who remained on phototherapy. This association remained even after accounting for age, sex, and other health factors such as diabetes, hypertension, and alcohol and tobacco use. These findings suggest that early use of biologic therapies in patients with moderate‐to‐severe psoriasis may help reduce the risk of future joint disease. Treating psoriasis effectively may not only improve skin symptoms but also help prevent or delay the onset of psoriatic arthritis, underscoring the importance of timely and targeted treatment.
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