To describe the psoriatic phenotype associated with psoriatic arthritis (PsA) METHODS: Based on the previously published PURE 4 validation study, this work aims to describe the sociodemographic and clinical characteristics, as well as the PURE-4 questionnaire outcomes, of psoriasis patients who completed the study. It compares those diagnosed with PsA during the study to those with only psoriasis . The variables compared were age, gender, time since diagnosis of psoriasis, psoriasis location, psoriasis treatment, Psoriasis Area and Severity Index (PASI), and Dermatology Life Quality Index (DLQI).
Results
The study included 253 psoriasis patients, from whom 46 developed PsA (28 [60.9%] male; mean age 48.9 [11.1]) during the study. At baseline, patients who developed PsA had more involvement of psoriasis in the neck (13.0% vs. 3.4%, p<0.01), knees (71.4% vs. 50.0%, p=0.02), hands (40.0% 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 [5.6] vs. 6.8 [5.0], p=0.03) and DLQI (9.9 [6.9] vs. 7.6 [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% in Assessment I to 91.7% in Assessment II (91.7% vs. 45.4%, p<0.01).
Conclusion
Greater psoriasis involvement in neck, knees, hands, and feet as well as high impact areas of patients who developed PsA suggests additional information on arthritogenic phenotype of psoriasis in our study population compared to locations generally linked to arthritis risk (nail or scalp).
