Delays in the diagnosis and treatment of psoriatic arthritis (PsA) are common. These delays contribute to impairments in quality of life and joint damage. This study aims to calculate the incidence rate of PsA over time and identify clinical features that may be used for PsA prediction in psoriasis patients.The study population for PsA incidence analysis included 1128 participants enrolled in the Utah Psoriasis Initiative (UPI) between 2002 and 2014. Clinical evaluation and medical record review were performed to identify new cases of PsA after enrollment. For identifying psoriasis features associated with PsA, the population was restricted to 627 participants who did not have PsA before psoriasis phenotyping and had been followed up for subsequent PsA diagnosis. We conducted Cox proportional hazard regressions to estimate the hazard ratio (HR) of PsA associated with psoriasis characteristics and other health-related features.PsA incidence rate increased for >60 years following psoriasis onset (trend p<0.0001). There was a significant association between PsA and induration severity in untreated lesions (p<0.001, HR=1.46), history of fingernail involvement (p<0.001, HR=2.38), pustular psoriasis (p<0.001, HR=3.32), fingernail involvement at enrollment (p<0.001, HR=2.04), and Koebner phenomenon (p<0.001, HR=1.90). Multivariate analysis yielded a model which included a history of fingernail involvement (p<0.001, HR=2.16) and untreated induration (p<0.001, HR=1.41).Risk of PsA increases steadily for >60 years following psoriasis onset. Patient-reported history of psoriasis characteristics has greater predictive power than physician measured features at enrollment visits. The characteristics identified in this study provide guidance for screening for PsA risk in psoriasis patients.
Sophie Belman, Jessica A Walsh, Courtney Carroll, Michael Milliken, Benjamin Haaland, Kristina Callis Duffin, Gerald G Krueger, Bing-Jian Feng