Patients with psoriatic arthritis have worse quality of life than those with psoriasis alone

OBJECTIVE: PsA is an inflammatory arthritis present in ∼30% of people with psoriasis (PsC). Both conditions have a significant impact on quality of life (QoL). Our objective was to test the hypothesis that people with PsA have poorer QoL than patients with PsC because of the added burden of arthritis, age and comorbidities. METHODS: Consecutive patients with PsA (CASPAR criteria) and PsC were approached to participate in this study. Patients with PsC were examined by a rheumatologist using a standardized protocol to exclude PsA. Patients completed the HAQ, Medical Outcome Study 36-item Short Form Health Survey, Dermatology Life Quality Index (DLQI), EuroQoL 5 domains (EQ-5D) and Fatigue Severity Scale (FSS). Mean scores were compared and multivariate analyses were conducted to compare the QoL measures between the two patient groups. RESULTS: Two hundred and one patients with PsC and 201 patients with PsA were studied. A significant decrease in QoL for patients with PsA compared with those with PsC was identified by all questionnaires except for the DLQI. This skin-specific questionnaire revealed a lower QoL in patients with PsC. Multivariate analyses for each QoL measure confirmed the results of these analyses. After adjusting for age, sex, duration of PsC, comorbidities, DMARDs and biologic therapy, HAQ and DLQI were independently associated with PsA in a logistic regression. CONCLUSION: Patients with PsA have a poorer QoL compared with those with PsC as measured by all questionnaires except the DLQI.