Association of enthesitis with severity of psoriasis in psoriatic arthritis: an observational study

The relationship between dermatological and articular manifestations of psoriatic disease remains incompletely elucidated. There is no strong correlation between the severity of cutaneous psoriasis and the clinical phenotypes of psoriatic arthritis (PsA). This study aims to examine the correlation between the severity of psoriasis and various clinical features, including measures of severity and activity of PsA, in a real-world clinical setting. Seventy-six consecutive adult patients of both genders with confirmed diagnoses of psoriatic arthritis (PsA) and psoriasis were included in the study. The Psoriasis Area and Severity Index (PASI) was assessed alongside various PsA variables: tender joint count (TJC), swollen joint count (SJC), duration of morning stiffness, presence of dactylitis and number of affected digits, presence of enthesitis and Maastricht Ankylosing Spondylitis Enthesitis Score (MASES), patient's global assessment (PGA), and examiner's global assessment (EGA). Associations were analyzed using the Spearman correlation test and the Kruskal-Wallis test. Statistical significance was established at p = 0.05. Forty-two men and thirty-four women, median age of 56 (range 33-85) years, participated in the study. The median duration of psoriasis was 216 (range 0-600) months and median duration of PsA was 120 (range 7-456) months. There was no significant correlation between PASI and any PsA variables, except for the correlation between PASI and the presence of enthesitis (ρ = 0.285; p = 0.013). Moreover, older patients and patients with a long history of psoriasis manifested more often with enthesis as a sign of PsA. Our findings emphasize the correlation between the severity of psoriasis and presence of enthesitis in patients with PsA.