PMR and Palindromic Rheumatism Similarities Save

TRANSCRIPT:

Hello, my name is Kulveer Mankia. I'm a rheumatologist based in Leeds in the UK, and in this video I'd like to discuss the similarities between polymyalgia rheumatica and palindromic rheumatism (PR). And in doing that, highlight how these similarities help us understand the relationship between polymyalgia rheumatica and rheumatoid arthritis. 

So if we begin with palindromic rheumatism, whether PR should be considered part of the rheumatoid continuum has been a long debated topic. And perhaps not everybody watching this will be very familiar with palindromic rheumatism. It is considered uncommon, but every rheumatologist sees it in their practice. And the clinical presentation of palindromic rheumatism is very distinctive. It's the hallmark of the condition. Patients present with extremely painful episodic flares that cause swelling, tenderness, redness in and around the joints. It usually affects one or a few joints at a time, and then quickly resolves and characteristically patients are asymptomatic between their flares. 

And the first point I'd like to highlight in terms of similarities between palindromic rheumatism and PMR is that both of these conditions are recognized precursors or prodromes, which are known to proceed the development of rheumatoid arthritis in some patients. So for PR, we know that around 50% of patients will eventually go on to develop rheumatoid arthritis. And anti CCP positivity is a major risk factor for that progression. So in those cases, people would transition from a relapsing remitting pattern to a persistent rheumatoid synovitis. And similarly, polymyalgia rheumatica is a well-recognized precursor or prodrome of rheumatoid arthritis, particularly in older patients, uh, so-called late onset rheumatoid arthritis. There are clinical differences between the 2:00 PMR doesn't usually present in a relapsing remitting fashion, but although there is diurnal variation in the symptoms, and typically polymyalgia is seronegative while the majority of PR cases are seropositive. But that said, what is known is that there are clearly subgroups of auto-antibody positive individuals that will have a PR or a PMR prodromal phase before they progress to a more typical rheumatoid arthritis diagnosis. And it's thought that around 20% of patients with rheumatoid arthritis will go through a palindromic prodromal phase before they develop definite rheumatoid arthritis with the other 80% instead having a daily arthralgia or stiffness. 

The other area of similarity between PR and polymyalgia is the anatomical distribution of the inflammation that we see in these conditions. And high resolution imaging studies have been very informative in this regard. Ultrasound and MRI studies have shown that PR and polymyalgia are notably characterized by extracapsular inflammation around the joints. Often in the absence of synovitis and work that's taken place in Leeds has shown that ultrasound assessment during flares of PR reveals marked periarticular inflammation. And we see peritendinitis, tenosynovitis, periarticular edema, even subcutaneous edema, and this often occurs without an associated synovitis. Similarly, in polymyalgia, PMR, MRI data shows that extracapsular bursal inflammation is the predominant finding around the joints as opposed to a discreet synovitis. So again, if we bring this back to how these conditions, uh, can represent precursors or prodromes of rheumatoid, we know more broadly in individuals at risk of rheumatoid arthritis in the prodromal phase, for example, those with symptomatic seropositive arthralgia, we frequently see 10 synovitis and peritendinitis inflammation on MRI. And that marker is a really strong predictor of progression to eventual rheumatoid arthritis. 

And a third similarity between PMR and Palindromic rheumatism to consider is response to treatment. Both these conditions are very responsive to glut glucocorticoids alone, and often unlike in rheumatoid arthritis, additional disease modifying therapy is not required to achieve a sustained drug-free remission. And that responsiveness to steroid may reflect, again, the anatomical location of the inflammation in these, in these conditions. Uh, we all know that 10 synovitis burrs cell inflammation, tendon inflammation is very steroid responsive and often, uh, PR will come into control with intermittent use of steroid alone and polymyalgia rheumatica, while it does require a longer duration of steroid therapy, will also successfully remit in the medium to long term without the requirement of an additional DMARD. And so those are my key points on similarities between palindromic rheumatism and polymyalgia rheumatica and how they might relate to rheumatoid arthritis. 

Thank you very much for watching.