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Updated: Aug 9, 2026

Measuring Psoriasis Severity at Home
Published on: March 1, 2024
Leflunomide improves psoriasis in patients with psoriatic arthritis: an in-depth analysis of data from the TOPAS
Peter Nash1, Diamant Thaçi, Frank Behrens
1Nambour General Hospital and University of Queensland, Brisbane, Australia. pnash@tpg.com.au
Background:
Leflunomide has shown promise in the treatment of psoriasis.
Objective:
To provide an in-depth analysis of the effect of leflunomide on psoriasis in patients with psoriatic arthritis (PsA).
Methods:
190 patients with plaque psoriasis (at least 3% skin involvement) and active PsA were randomized to double-blind treatment with leflunomide (100 mg/day loading dose for 3 days followed by 20 mg/day orally) or placebo for 24 weeks.
Results:
As previously reported, leflunomide resulted in a significantly higher Psoriatic Arthritis Response Criteria response rate than placebo (58.9 vs. 29.7%; p < 0.0001). Significant differences in favor of leflunomide were also observed in the Psoriasis Area and Severity Index (PASI 50 in 30.4% of patients vs. 18.9% for placebo; p = 0.05), target lesion response (46.4 vs. 25.3%; p = 0.0048), combined skin and joint response (27.2 vs. 8.9%; p < 0.0001), Dermatology Life Quality Index (improvement of 1.9 points vs. 0.2; p = 0.0173) and certain SF-36 subdomains. Dermatological responses were observed at the earliest examination (4 weeks) and increased throughout the 24-week study.
Conclusion:
Once-daily oral leflunomide is an effective and convenient treatment for PsA and plaque psoriasis.
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