The burden of psoriasis in patients with early psoriatic arthritis.

Objectives: Psoriasis impacts health-related quality of life (HRQoL) in PsA patients. However, this is not adequately measured with a general HRQoL questionnaire. The aim of this study was to quantify the degree of psoriasis evolution in PsA patients over the first year of follow-up and to evaluate whether the impact of psoriasis on HRQoL can be adequately measured with a dermatology-specific HRQoL questionnaire.

Methods: Data were used from PsA patients in the Dutch south west Early Psoriatic Arthritis cohort. Psoriasis severity was measured with the Psoriasis Area and Severity Index (PASI). Dermatology-specific HRQoL was assessed with the Skindex-17 questionnaire. We used a Sankey diagram to illustrate the evolution of psoriasis severity during the first year of follow-up. To assess the association between psoriasis severity and the symptoms and psychosocial subscale of the Skindex-17, a linear regression analysis with hierarchical variable selection and zero-inflated negative binominal regression analysis were performed, respectively.

Results: We included 644 patients; 109 (17%) patients had no psoriasis (PASI = 0), 456 (71%) had mild psoriasis (PASI < 7), 56 (9%) had moderate psoriasis (PASI 7-12) and 23 (4%) had severe psoriasis (PASI > 12). Psoriasis severity did not fluctuate much during the first year. PASI was significantly associated with both subscales of the Skindex-17 at baseline and 12 months.

Conclusion: Psoriasis severity in PsA patients is mostly mild but impacts HRQoL when measured using a dermatology-specific HRQoL questionnaire. For optimal management of PsA patients, we recommend rheumatologists acquire information on skin burden by using a dermatology-specific HRQoL questionnaire.