Diagnosis Chronic Polyarthritis / rheumatoid arthritis

Regardless whether you call the disease chronic polyarthritis or rheumatoid arthritis, the diagnosis is somehow incomplete and summarizes too many different entities. The revenue relevant ICD classification doesn’t do justice to these differences; at this point one could argue that the ICD hasn’t been made for this purpose. Let’s go through some points regarding differences in the diagnosis rheumatoid arthritis.

An old classification is that into seropositive (with rheumatoid factor) and seronegative (without rheumatoid factor) chronic polyarthritis; the level of importance for rheumatoid factor is unclear, but this point isn’t found in the diagnosis (look at rheumatoid factor on this blog: http://rheumatologe.blogspot.com/2012/02/rheumatoid-factor.html). An acute form is unknown, rheumatoid arthritis is a chronic disease. Of course, there are also forms of acute polyarticular arthritis, but these are other diseases and not an acute form of rheumatoid arthritis. In Germany you can still see rheumatoid arthritis being labeled as chronic polyarthritis or even “primary chronic polyarthritis”, which creates the problem clearify, why you distinguish a mon- or oligo forms of rheumatoid arthritis and then choose a new name for the a form of more joints. Well, the Inuit language has a great variety of word for which we call snow, but that’s a different story.


The pattern of affected joints may be symmetric, asymmetric, small or large joints, or only the wrists, but this fact isn’t considered so far at all in ICD or common usage of diagnosis.

ACPA are used now in the classification criteria of ACR/EULAR. Studies on the predictive value of the amount of ACPA would be useful. Currently the diagnosis of rheumatoid arthritis according to ICD leaves ACPA status open. There’s evidence, especially from a certain level of ACPA, showing an association with an increased risk for the development of joint destructions, so that the inclusion in the diagnosis is warranted.


Radiological (or other imaging) findings are also inadequately represented, on average, you could install easily non erosive, erosive or mutilating in the diagnosis.


The disease may be accompanied by other autoimmune phenomena, so you should also consider representing this fact in your diagnosis. After all it saves us from creations such as rhupus.

Disease activity is unimportant for a classification, but not for the users of the diagnosis. At this point, regarding the treatment, the diagnosis may be of significant difference, if disease activity between the extremes remission and highly active is communicated.


And we also should indicate the duration of the disease, because it allows to draw conclusions about the aggressiveness of the disease,


The last part shows the individual diagnoses and their classification according to ICD. Why the diagnosis of rheumatoid nodules falls under the seronegative rheumatoid arthritis is unclear, because most of the patients with rheumatoid nodules are seropositive.


All in all, the ICD classification already offers a more sophisticated look, but still is completely inadequate in my view.

(This text has been translated and adapted from a preexisting German version, so around the world there might be differences in the usage of certain words.)