BACKGROUND: Despite increasing awareness of the disease, rates of undiagnosed psoriatic arthritis (PsA) are high in patients with psoriasis (PsO). The validated Psoriasis Epidemiology Screening Tool (PEST) is a 5-item questionnaire developed to help identify PsA at an early stage.

OBJECTIVES: To assess the risk of possible undiagnosed PsA among patients with PsO and characterize patients based on PEST scores.

METHODS: This study included all patients enrolled in the Corrona Psoriasis Registry with data on all 5 PEST questions. Demographics, clinical characteristics, and patient-reported outcomes were compared in Corrona Psoriasis Registry patients with PEST scores ≥ 3 and < 3 using t-tests for continuous variables and chi-squared tests for categorical variables; scores ≥ 3 may indicate PsA.

RESULTS: Of 1516 patients with PsO, 904 did not have dermatologist-reported PsA; 112 of these 904 patients (12.4%) scored ≥ 3 and were significantly older, female, less likely to be working, and had higher BMI than patients with scores < 3. They also had significantly longer PsO duration, were more likely to have nail PsO, and had worse health status, pain, fatigue, Dermatology Life Quality Index, and activity impairment.

CONCLUSIONS: Improved PsA screening is needed in patients with PsO because the validated PEST identified over one-tenth of registry patients who were not noted to have PsA as having scores ≥ 3, who could have had undiagnosed PsA. Appropriate, earlier care is important because these patients were more likely to have nail PsO, worse health-related quality of life, and worse activity impairment. This article is protected by copyright. All rights reserved.