Induction of Cure in Early Arthritis (I CEA): study protocol for an investigator-initiated randomized single-blind clinical trial with open-label extension to compare three treatment strategies in patients with newly diagnosed undifferentiated arthritis.

Background: Undifferentiated arthritis (UA) is a term used to describe patients with inflammatory arthritis that has not differentiated into a specific rheumatic disease. UA may be a pre-stage of rheumatoid arthritis (RA) or another inflammatory disease or remain undifferentiated, but a substantial proportion of patients may also achieve spontaneous remission. As UA may be an early presentation of RA, rheumatologists often start methotrexate (or another csDMARD) as early as possible.