Clinical Characteristics of 'Severe' Peripheral Psoriatic Arthritis: A Retrospective Analysis of a Longitudinal Cohort

Abstract Introduction The concept of severity in a multidomain disease such as psoriatic arthritis (PsA) is still not well defined. The aim of this study was to identify the clinical characteristics of patients with severe peripheral PsA. Methods Retrospective analysis of a longitudinal cohort. Demographic and clinical characteristics of patients with PsA were collected at baseline and at last follow-up. We defined the severe population using the modified Composite Psoriatic Disease Activity Index (mCPDAI); which excludes ankylosing spondylitis quality of life scale). Hence, patients with a score of 3 in at least one domain were defined as having severe PsA. Clinical characteristics of patients fulfilling the definition of severe PsA were compared to those non-severe. Results We evaluated 177 patients with peripheral PsA (M/F: 98/76). Of these, 64 (36.1%) were identified as severe according to the mCPDAI criteria, at baseline. Eighteen patients (10.1%) at last follow-up still met the definition of severe PsA. At last follow-up visit, severe patients with PsA were only males (18/18, P