Background/Purpose: The Psoriasis Epidemiology Screening Tool (PEST) is a 5-item questionnaire developed to help identify psoriatic arthritis (PsA) at an early stage, with a score ≥ 3 indicative of PsA.¹ A recent Korean study found that a PEST score of 2 may be a more favorable cutoff for screening patients with psoriasis (PsO).² The objectives of this study were to assess the risk of undiagnosed PsA among patients with PsO and characterize patients based on PEST scores in the US-based Corrona Psoriasis Registry.

Methods: This study included all patients enrolled in the Corrona Psoriasis Registry with data on all 5 PEST questions. Demographics, disease characteristics, patient-reported outcomes and medication use were analyzed at the time of enrollment and stratified by PEST score (0, 1, 2 or ≥ 3). Pairwise comparisons were made between PEST score = 0 (reference) and other PEST score groups using t tests for continuous variables and χ² tests for categorical variables.

Results: As of June 2016, 99.1% (1516/1529) of patients in the Corrona Psoriasis Registry had data on all 5 PEST questions; 612 patients (40.4%) had dermatologist-reported PsA at enrollment. Among the remaining 904 patients, 421 patients (46.6%) had a PEST score = 0, 225 (24.9%) had a PEST score = 1, 146 (16.2%) had a PEST score = 2 and 112 (12.4%) had a PEST score ≥ 3. Of patients with a PEST score ≥ 3, patients most commonly answered “yes” to “have you ever had a swollen joint (or joints)?” (89%) and “has a doctor ever told you that you have arthritis?” (86%). Compared with patients with a PEST score = 0, patients with a PEST score ≥ 1 all had a higher body mass index, longer duration of PsO, increased family history of PsA, increased prevalence of nail PsO and worse EQ VAS at enrollment (all P < 0.05; Table 1). In addition, patients with PEST scores ≥ 2 were older, more likely to be female, less likely to be employed and had an increased family history of PsO, worse pain and fatigue, worse dermatology-related quality of life and higher percentage impairment of daily activities due to psoriasis at enrollment vs patients with a PEST score = 0 (all P < 0.05). There were no significant differences across PEST scores in affected body surface area or PASI scores.

Conclusion: In this cohort of PsO patients with no diagnosis of PsA, patients with PEST scores ≥ 2 were significantly different from those with PEST scores = 0 for many characteristics at enrollment, including body mass index and patient-reported outcomes. These findings highlight the value of screening for PsA among patients with PsO in order to potentially improve patient outcomes.

References:

1.)   Ibrahim GH, et al. Clin Exp Rheumatol. 2009;27(3):469-74.

2.)   Ha YJ, et al. Arthritis Rheumatol. 2016;68(suppl 10):A2744.