Dactylitis and Early Onset Psoriasis in Psoriatic Arthritis: Are they Markers of Disease Severity? A Clinical Study

Objectives: To stratify psoriatic arthritis (PsA) patients based on psoriasis (PsO) onset age: early onset psoriasis (EOP) vs. late onset psoriasis (LOP), and to assess if there are differences in disease characteristics, activity/function/impact of the disease, and comorbidity indices.Methods: Cross-sectional analysis of a longitudinal PsA cohort. Patients were stratified based on PsO onset age.Results: One hundred and sixty PsA patients were enrolled (84 in EOP and 76 in LOP group) in the study. EOP PsA patients seem to have an increased probability to have dactylitis rather than LOP ones, OR 9.64 (3.77-24.6). Comorbidity indices (Rheumatic Disease Comorbidity Index and Charlson Comorbidity Index) were higher in LOP PsA patients, but these data were not confirmed when adjusted by age and sex. There are also differences in the treatment regimen: EOP PsA patients were more frequently treated with anti-interleukin (IL) 17; instead, LOP patients were more frequently treated with non-steroid anti-inflammatory drugs and conventional synthetic disease-modifying antirheumatics drugs. There were no differences in the disease activity, function, or impact of the disease.Conclusions: There are some clinical and therapeutic differences in PsA patients linked to the PsO onset age, namely dactylitis in EOP. Other characteristics found were: a "comorbidities trend" in LOP patients and a more frequent use of anti-IL17 in EOP