Palindromic rheumatism (PR) is a syndrome characterised by recurrent, self-resolving inflammatory attacks in and around the joints, consists of arthritis or periarticular soft tissue inflammation. The course is often acute onset, with sudden and rapidly developing attacks or flares. There is pain, redness, swelling, and disability of one or multiple joints. The interval between recurrent palindromic attacks and the length of an attack is extremely variable from few hours to days. Attacks may become more frequent with time but there is no joint damage after attacks. It is thought to be an autoimmune disease, possibly an abortive form of rheumatoid arthritis. Presentation
The exact prevalence of palindromic rheumatism in general population is unknown, and this condition is often considered a rare disease by nonrheumatologists. However, recent Canadian study showed that the incidence of PR in a cohort of incident arthritis was one case of PR for every 1.8 cases of rheumatoid arthritis (RA). The incidence of PR is less than that of RA but is not as rare as that was thought to be. Palindromic rheumatism is a syndrome presented with inflammatory para-arthritis (soft tissue rheumatism) and inflammatory arthritis both of which cause sudden inflammation in one or several joints or soft tissue around joints. The flares usually present with  mono- or oligo-articular involvement, which have onset over hours and last a few hours to a few days, and then go away completely. However episodes of recurrence form a pattern, with symptom-free periods between attacks lasting for weeks to months.
It is often a case of eliminating the other conditions before getting the correct diagnosis due to there being no specific test for PR diagnosis. No single test can confirm a diagnosis. A doctor may make a diagnosis based on medical history and signs and symptoms. Palindromic rheumatism must be distinguished from acute gouty arthritis and an atypical, acute onset of rheumatoid arthritis (RA). Without specific tests (such as analysis of joint fluid), it may be difficult to distinguish palindromic rheumatism from other episodic joint problems. It is important to note that a person may experience more than one autoimmune disorder at the same time, as overlap syndrome. Laboratory findings are usually normal. Blood tests may show an elevation of the ESR and CRP, but are otherwise unremarkable. Rheumatoid factor may be present especially in the group that is likely to develop rheumatoid arthritis. Proposed classification by Guerne and Weismann in 1992:
A 6-month history of brief sudden-onset and recurrent episodes of monoarthritis or rarely polyarthritis or of soft tissue inflammation. Direct observation of one attack by a physician. Three or more joints involved in different attacks. No radiologic evidence of bone or joint erosion. Exclusion of other arthritides, such as rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), or gout

Management
Treatment may include nonsteroidal anti-inflammatory drugs (NSAIDs) for acute attacks. Antimalarials, such as hydroxychloroquine, have been helpful in reducing the frequency and duration of attacks and may reduce the likelihood that palindromic rheumatism will progress to rheumatoid arthritis.