Using TNF-alpha inhibitors (TNFi) in people with severe psoriasis is more effective at preventing psoriatic arthritis (PsA) than narrow-band UVB (nbUVB) phototherapy over almost 10 years, new research has found.

With current conflicting research about the benefits of TNFi for people with psoriasis, this study provides strong evidence that long-term TNFi treatment helps to protect patients with severe psoriasis from developing PsA.

The study included 946 adults with severe psoriasis who were treated with either TNFi (n = 497) or nbUVB phototherapy (n = 449) between September 2005 and September 2010, with median follow-up times of 9.6 ± 2.6 years and 9.4 ± 5.9 years, respectively.

The researchers used propensity score (PS) matching to create comparable groups of treated and untreated individuals, accounting for variables such as arthralgia, family history, body mass index (BMI) – all of which are known risk factors for PsA – as well as Psoriasis Area Severity Index (PASI) score and psoriasis distribution.

All patients underwent a rheumatologist assessment before therapy and were evaluated for a PsA diagnosis before treatment.

A protective effect with TNFi?

The results showed that patients in the nbUVB group were more than twice as likely to develop psoriatic arthritis compared to those treated with TNFi therapy.

Time-dependent Cox regression confirmed that TNFi treatment reduced the risk of developing PsA, showing that patients who received this treatment were 68% less likely to develop the condition (hazard ratio (HR) of 0.32).

The study also found that arthralgia (HR = 7.68), nail psoriasis (HR = 1.93) and a higher PASI score (HR = 1.03 per point increase) were independent predictors of PsA, increasing the risk of developing the condition.

TNFi therapy reduced the risk of developing PsA by more than half compared to phototherapy, suggesting that long-term use of TNFi may have a protective effect against PsA in this patient group.

Future research will focus on how different biologic treatments affect the development of PsA in psoriasis patients and explore significant predictors of PsA, such as nail psoriasis, family history of PsA, severe skin symptoms and joint pain, the researchers explained.

These findings highlight the role dermatologists can play in identifying psoriasis patients at higher risk of developing PsA, they added.

Reference
Piaserico S et al. TNF-alpha inhibitors reduce the incidence of PsA in patients with psoriasis: a propensity score-matched cohort study. Rheumatology (Oxford) 2025 Jul 3:keaf364.