Palindromic rheumatism: A challenge in surveillance

Palindromic rheumatism (PR) is a clinical syndrome characterized by recurrent, transient episodes of joint pain, erythema, and swelling, typically without resulting in permanent joint damage. Ultrasonographic studies have shown that extra-capsular inflammation is a distinctive feature of this condition. PR flares are frequently monoarticular and commonly involve joints also affected in rheumatoid arthritis (RA), particularly the proximal interphalangeal, metacarpophalangeal, and wrist joints. Although clinical experience has long suggested that PR may represent an atypical form or precursor of RA, recent genetic analyses, particularly whole-exome sequencing, have revealed notable distinctions between the two diseases. In some patients with PR, mutations in the MEFV gene have been identified, further supporting its heterogeneous nature. RA remains the most frequent definitive diagnosis in patients with PR, especially in those positive for anti-citrullinated peptide antibodies. However, a subset of PR cases may evolve into other systemic autoimmune rheumatic diseases, such as systemic lupus erythematosus. In many patients, PR persists for years with recurrent flares or may enter remission, which may be prolonged but not necessarily permanent. Lifelong monitoring is essential, as flares can recur unpredictably. Management strategies for PR often mirror those of RA. Early and effective suppression of extra-capsular inflammation during PR flares may be as crucial as the "window of opportunity" concept in RA, potentially influencing long-term outcomes