Effect of low dose methotrexate as an add-on therapy in patients with palindromic rheumatism unresponsive to hydroxychloroquine: An observational study

Objective: Palindromic rheumatism (PR) is characterized by repetitive attacks of arthritis and/or periarthritis. There is inadequate data regarding the role of low dose methotrexate in patients with PR. The aim of this study was to determine the efficacy of low dose methotrexate add-on therapy in patients with PR with inadequate response to hydroxychloroquine (HCQ) monotherapy.

Methods: In this observational study, between August 2016 and July 2019, 15 patients with seropositive PR with inadequate response to HCQ (≥ 2 attacks per month even after 6 months of therapy) were included. All patients were treated with oral low dose methotrexate in addition to HCQ. The responses to therapy were monitored 3 and 6 months after adding methotrexate.

Results: In our study, of the 15 patients with PR, two-third were female, with a mean age of 45.73±9.18 years. All were seropositive (Rheumatoid factor positive in eight patients; anti-cyclic citrullinated peptide [CCP] positive in 11 patients; both Rheumatoid factor and anti-CCP positive in four patients). The average number of attacks at baseline was 5.6±2.8, and the median duration of attacks was 2 years. All patients had significant response to add-on methotrexate therapy at follow-up after 3 and 6 months; none developed Rheumatoid arthritis (RA) after 2 years of follow-up.

Conclusion: Low dose methotrexate is an effective add-on therapy in patients with PR having inadequate response to HCQ.