Understanding the Psoriasis Phenotype Associated With Psoriatic Arthritis Using the PURE-4 Questionnaire: Insights...

To describe the psoriatic phenotype associated with psoriatic arthritis (PsA).

Based on the previously published 4-item Psoriatic Arthritis Uncluttered Screening Evaluation (PURE-4) validation study, this work aims to describe the sociodemographic and clinical characteristics, as well as the PURE-4 questionnaire outcomes, of patients with psoriasis (PsO) who completed the study. It compares those diagnosed with PsA during the study to those with PsO only. The variables compared were age, sex, time since diagnosis of PsO, PsO location, PsO treatment, Psoriasis Area and Severity Index (PASI), and Dermatology Life Quality Index (DLQI).

The study included 253 patients with PsO, from whom 46 developed PsA (28 [60.9%] male; mean age 48.9 [11.1] years) during the study. At baseline, patients who developed PsA had more involvement of PsO in the neck (13% vs 3.4%, P < 0.01), knees (71.4% vs 50%, P = 0.02), hands (40% vs 17.7%, P < 0.01), and feet (22.9% vs 9.8%, P = 0.03) as well as high-impact areas. PASI (8.7 [SD 5.6] vs 6.8 [SD 5.0], P = 0.03) and DLQI (9.9 [SD 6.9] vs 7.6 [SD 6.7], P = 0.09) values were higher among patients with PsA. Peripheral joint pain with swelling (item 4) was the most prevalent item of PURE-4 among patients with PsA, ranging from 67.6% (vs 47.1%; P = 0.03) in Assessment I to 91.7% (vs 45.4%; P < 0.01) in Assessment II.

Greater PsO involvement in neck, knees, hands, and feet as well as in high-impact areas of patients who developed PsA provides additional information on the arthritogenic phenotype of PsO in our study population compared to locations generally linked to arthritis risk, such as the nails or scalp.