The differences between OA and RA...

There are many differences between Osteoarthritis and Rheumatoid Arthritis, a lot of people get the two very different conditions confused.

Hopefully the infographic below will help clear things up!...

[ITYFIALMCTT]

"There are many differences between Rheumatoid Arthritis and Osteoarthritis, a lot of people get the two very different conditions confused."

Yes. And, No. Although it is a little contested, there also seems to be a growing research body around inflammatory osteoarthritis (aka erosive osteoarthritis). discoverymedicine.com/Allen...

It does seem as if some of the classic distinctions, as per the illustration, might be being called into question. E.g., even on the topic of systemic effects and causation, there is a putative relationship that associates dyslipidaemia and erosive osteoarthritis.

"individuals with erosive hand OA had more than twice the risk of metabolic syndrome (OR 2.7, 95% CI 1-7.1) and more than four times the risk of dyslipidemia (OR 4.7, 95% CI 2.1-10.6) compared with patients who had severe non-erosive OA, the researchers reported online in Annals of the Rheumatic Diseases.

Erosive hand OA differs from non-erosive disease in several ways. For instance, the onset of symptoms such as swelling, stiffness, and pain tends to be abrupt,"

medpagetoday.com/rheumatolo...

I may be wrong but at the stereotyped ends of the continuum, the distinctions seem very clear, but it does seem as if it's a continuum rather than totally separate conditions. Or, that osteoarthritis has been misunderstood in some ways. None of which makes it analogous to RA but there seems to be a fair amount of nuance that is omitted in categorisation, diagnosis and discussion. E.g., how many people here have reported changing diagnoses from one variety of IA to another over time? Sometimes several times?

[hawker955 in reply to ITYFIALMCTT]

As the above reply says. There are a lot of differences. Osteoarthritis is wear and tear of the joint surface and actually has little inflammation. This is the condition many people get as we get older. Some joints get more wear and tear than others of course. Footballers get this in the knees and others are affected more in other limbs. The conditions are very different really.

Rheumatoid is not wear and tear, it is a condition when for whatever reason your immune system attacks the linings of the joints. So you feel like you have an infection because there is so much inflammation occurring. Hence the treatment centres on anti-inflammatories to try and stop the process of joint destruction. OA treatment centres on pain relief and support of the joints to reduce wear and tear. RA can lead to extra wear and tear but is not caused by it in the first place.

RA involves fevers and sweats etc as though you do have a bad infection but that is just generalized inflammation going on.

HTH?

[ITYFIALMCTT in reply to hawker955]

Quoting from the first link I gave to illustrate that forms of osteoarthritis can be associated with episodes of inflammation, synovitis etc. which is why erosive/inflammatory osteoarthritis is one of the differential diagnoses for psoriatic arthritis and other seronegative arthropathies:

"Erosive osteoarthritis (EOA) represents a subset of symptomatic osteoarthritis of hand, characterized by intermittent and often frequent inflammatory episodes and progressive joint damage. A greater degree of inflammation and the presence of subchondral bone erosions on plain radiographs help distinguish EOA from generalized osteoarthritis of hand. High resolution ultrasound and magnetic resonance imaging (MRI) have demonstrated the presence of synovitis and MRI has additionally highlighted the role of inflammation in bone, tendons, and ligaments in EOA. "

[ITYFIALMCTT in reply to ITYFIALMCTT]

Replying to myself to tag in a useful review and because it doesn't seem too unusual for people at the outset to be in the no-man's land of seronegative RA or one of the other arthropathies such as PsA:

"Rheumatologists have long considered OA and PsA as two completely distinct arthropathies. This review highlights how some forms of generalized OA and PsA may afflict the same entheseal-associated anatomical territories. While degeneration or inflammation may be clearly discernible at the two extremes, there may be a group of patients where differentiation is impossible."

Differentiation between osteoarthritis and psoriatic arthritis: implications for pathogenesis and treatment in the biologic therapy era

academic.oup.com/rheumatolo...

[helixhelix in reply to ITYFIALMCTT]

My older sister has erosive osteoarthritis, which her rheumy classes as an inflammatory disease so tips it more towards our end of the spectrum. My other sister has another auto-immune disease, which makes as all believe that the spectrum is pretty wide since we all have same parents and environment in first years of our life.

But I do agree that it is a spectrum, as is the spectrum between lupus, rhupus and RA for example. But sometimes it helps to draw distinctions as that covers 95% of the time.

On one hand I get exasperated with the "aunty's got that in her thumb brigade" so something that simply shows the difference is useful. On the other hand I feel for people with severe OA as it's hell - so this schematic also helps show that it can be more widespread (although treatment not so complex is not accurate as the reality is that treatment is sadly limited).

But I would love my rheumy to think I'm an emergency at times!

[keeta in reply to helixhelix]

Well said love x

[ITYFIALMCTT in reply to helixhelix]

Do you have a source for this, please, helixhelix : "sometimes it helps to draw distinctions as that covers 95% of the time".

I tried looking up varieties of osteoarthritis: I couldn't find estimates as to how many times erosive osteoarthritis is a missed diagnosis, or a misdiagnosis for seronegative arthropathies or seronegative RA but I couldn't find any useful numbers (good chance I was looking in the wrong places).

[ITYFIALMCTT]

I wonder how many cases of erosive osteoarthritis are not diagnosed because NICE guidelines indicate that there is no need for imaging or referral if a GP suspects that someone has osteoarthritis. Likewise, some CCGs won't permit referrals if a GP suspects a seronegative inflammatory arthropathy (for which EO might be a differential diagnosis).

I was interested to see several papers that move beyond the, "Oh, it makes no difference - just treat EO with NSAIDs etc.'" to those who advocate methotrexate and other medications more associated with IA in order to halt the erosions. That said, there's an upcoming publication that uses MTX to counter the synovitis of knee osteoarthritis: "A recent open-label pilot study of 30 patients with knee OA who took a MTX dose of 15–20 mg/week for 6 months suggested an analgesic benefit, with 43% achiev- ing the Osteoarthritis Research Society International (OARSI) responder criteria".

eprints.whiterose.ac.uk/110...

I wonder if the more useful distinction will eventually prove to be not osteoarthritis v inflammatory arthritis/arthropathies but osteoarthritis v auto-immune arthropathies?

[ITYFIALMCTT]

Hidden I'd be interested if you have any reviews of how many people fall into the distinct categories of this infographic, please?

And is this infographic meant to be literally about RA or is it an umbrella term that includes other inflammatory arthropathies?

[Witness2]

As an infographic intended to inform the wider population, I think it does the job. I'm not sure joe public is ready to understand nor care about the subtle similarities/differences in the way that we might be. As an 'at a glance' piece of display material I think it's really helpful - plus it's sparked this interesting debate which I'd have known nothing about otherwise! Thanks all. Oh, and I loved the medical emergency bit too...if only!