Comparison of Adults With Polyarticular Juvenile Idiopathic Arthritis to Adults With Rheumatoid Arthritis: A Cross-sectional Analysis of Clinical Features and Medication Use.

Background/objective: Many individuals with juvenile idiopathic arthritis (JIA) have persistent disease into adulthood. Polyarticular JIA (pJIA) is often mislabeled as rheumatoid arthritis (RA) in adult rheumatology clinics, and treatment for adult pJIA patients is not well defined. We aimed to describe clinical features and medication use in the adult pJIA population in relation to an RA control cohort.