Incidence and risk of developing rheumatic diseases in 19,724 patients with palindromic rheumatism in South Korea: A nationwide population-based study

•The incidence rate of PR was estimated to be one sixth of that of RA.•Patients with PR have an increased risk of developing various rheumatic diseases including seropositive RA.•The rate of progression to seropositive RA among PR patients was 8.79%.•In patients with PR, the progression risk to RA was lower than those reported previously.