Oligoarticular vs. Polyarticular Psoriatic Arthritis Save

A psoriatic arthritis (PsA) cohort analysis reveals many similarities and few distinctions between those who present with oligoarticular and polyarticular PsA.

A total of 402 PsA patients from the University of Toronto PsA clinic (1978 - 2018) were included. Oligoarthritis was defined by the presence of ≤4 inflamed joints and progression (to polyarticular) as an increase to ≥5 joints. 

Overall, 47% patients presented with oligoarthritis. Oligoarthritis and polyarthritis had similar demographic features and joint distribution, yet polyarthritis patients were more likely to present with dactylitis and enthesitis.

Over time 61% of oligoarthritis patients remained oligoarticular, while 39% progressed to polyarthritis. Lower SF-36 mental component summary score was the predictor for progressing to polyarthritis.

In oligo- and polyarticular PsA, most patients have small joint involvement, but 39% will progress to polyarthritis without clear clinical predictors.