Next stop, we're gonna talk about rheumatoid arthritis.
Let's go on to a case.
A 59-year-old history professor with a history of hypertension presents
with progressive fatigue and bilateral wrist pain and swelling over the past three to six months.
He blames his symptoms on starting amlodipine for his hypertension about six months ago.
He reports no fevers, weight loss or rash.
His wrist pain is non-radiating and it's a little bit more on the right side than the left side.
He reports that his hands and wrist feel stiff for nearly an hour every morning, loosening up a little bit with activity.
He smokes a pack a day, rare alcohol use, and his uncle has psoriasis, see if that's relevant later.
Looking at his initial vitals, pretty unremarkable.
Cardiopulmonary exam is also within normal limits and now let's take a look at his musculoskeletal exam.
So, no joint deformities are present but he has warm, boggy, swollen wrists bilaterally with mild tenderness to palpation.
No other joints are affected except for a 2 cm, firm, non-tender, immobile nodule noted on the left Achilles tendon.
Skin and nail exam are within normal limits.
So, let's highlight a few key features of this presentation thus far.
First, it's looking like it's chronic. It's been going on for three to six months.
It came on slowly and it's just slowly progressing. We couldn't consider those to be acute.
The pattern of joint involvement sounds symmetric and also oligoarticular,
remember that means that you have between two to four joints involved and in this case, he has both of his wrists at this point.
Next stop, is there evidence of joint inflammation? We've got several things supporting joint inflammation.
Number one, his wrists are boggy and swollen.
Secondly, he's got some mild tenderness to palpation and of equal importance
is the fact that he's saying that he has stiffness for more than an hour every morning.
All those things really support some immune-mediated process with some joint inflammation.
And lastly, is there systemic involvement? A little hard to say at this point.
All these reporting is fatigue which could be any number of different causes but we'll hold on to that for a moment.
So, let's take a look at our differential diagnosis.
Rheumatoid arthritis, systemic lupus erythematosus, osteoarthritis, psoriatic arthritis, and gout.
Now, what's missing on this list is amlodipine
and while I'd love to indulge our patient's concern that this all started with amlodipine,
I'm afraid that symmetric joint inflammation is just not a listed side effect for calcium channel blockers.
For the record, amlodipine can often present with bilateral lower extremity edema but that's not what we're dealing with here.
So, let's reflect on the case thus far and think about the factors for and against these five diagnoses on our list.
Rheumatoid arthritis. Well, in support of that diagnosis is his age,
it's appropriate about this time in someone's life for when RA could weared it's ugly head.
The presence of some systemic symptoms -- again, they're mild but they're present.
The symmetry, the fact that both wrists are involved
and the wrists themselves are the most common joint affected with rheumatoid arthritis,
with some inflammation and stiffness greater than an hour
and interestingly enough, the smoking history very much favors rheumatoid arthritis.
We know that smoking is both a predictor of developing RA and a predictor of disease progression and difficult with treatment.
And of course, this thing going on the back of his heel, maybe that's a rheumatoid nodule, which we'll talk about more later.
And against the diagnosis however is it's actually a 3 to 1 female to male ratio and our professor is a gentleman
and oftentimes when we think about rheumatoid arthritis, particularly on board exams,
we think about a lot of classic joint deformities like Boutonniere's deformity
and things like that and we're just not seeing any of those joint deformities.
But maybe we've caught the disease early. Leave a question mark for RA.
Let's talk about lupus. Lupus, boy that is a disease with systemic manifestations.
The wrist involvement would not at all be unusual with evidence of inflammation on exam.
But against it is even a stronger female to male divergence there. He's an elderly gentleman.
Most commonly -- we're talking about young, black women who get lupus, not old white men.
The absence of skin involvement would also steer us clear of lupus.
Nonetheless, we'll leave a question mark in the box for SLE as well.
Next stop, let's talk about osteoarthritis. In favor of osteoarthritis is his age.
Osteoarthritis is something that occurs with increasing age
and of course, it is dramatically more common than all of the autoimmune diseases combined.
It's the number one complaint in a person presenting to a primary care doctor's office with pain.
It gonna end up being osteoarthritis. However, the fatigue, not a typical feature of OA.
The stiffness greater than one hour, that is a significant thing in the idea of this being osteoarthritis.
Likewise, symmetric wrist swelling more often than not, osteoarthritis is a disease with asymmetric findings.
You know, like the right basal joint on one hand, the left knee on the other side and maybe the right hip.
You don't get the symmetry that we're seeing here.
Wrists swelling, well you can certainly have an acute synovitis with osteoarthritis.
It tends to be short-lived and not inflammatory and boggy, the way that we're hearing in our patient
and I don't know what to make of a nodule but that's not something we would see on osteoarthritis.
So, we'll keep it on the list but we're gonna have to get some inflammatory markers to see what's happening.
Next stop, on our differential diagnosis is psoriatic arthritis.
So, on the one hand in favor of it is his white race. It is more common amongst Caucasians.
The family history as well, his uncle had psoriasis,
that's gonna support that diagnosis and the fact that he has some systemic symptoms
and this oligoarticular inflammatory arthritis, you know, boggy wrists bilaterally.
However, in contrast, the things that go against psoriatic arthritis is he has no skin or nail involvement,
which would be very unusual for a patient with psoriatic arthritis
to have no manifestations of psoriasis prior to the symptoms of arthritis.
In addition, it's somewhat atypical joints.
It's more likely to involve the DIPs rather than the MCPs or the wrist.
So with that in mind, again, we'll leave a question mark but we're not feeling so good about psoriatic arthritis.
Lastly, gout. So, white older men with hypertension -- that is a very good setup for gout.
He does have oligoarticular inflammatory arthritis and you know that lesion that little bump on the back of his heel, it could be a tophus.
It's not a classic place for a tophaceous gout but it could certainly be a location where you might find that.
Against gout however, the symmetry would be unusual.
The chronicity, gout should really be more characterized by acute painful flares
and we're not getting that from his story and the morning stiffness is not a feature of gout.
So, I think we're gonna leave a question mark for gout as well.
I'm starting to feel like we're not getting anywhere with our differential diagnosis.
So, let's go take a look at some diagnostic data to hopefully help us out and tease this apart.
Let's take a look at some diagnostic information in hopes that this will help us with our differential diagnosis.
So first stop, the blood work.
So, the uric acid is 6.1, that's gonna steer us away from acute gout
but always keep in mind that uric acid level can be falsely low on a setting of an acute flare.
Hemoglobin, it looks like we have a mild anemia which is very non-specific.
White blood cell count of 6.4. Creatinine is 1.1. Not too helpful in the initial blood work.
Let's move on to the inflammatory markers.
So, rheumatoid factor is not just positive, it's highly positive.
Always be mindful of the fact that a number of different conditions can cause an elevated rheumatoid factor
but that is gonna lean us towards rheumatoid arthritis.
Much more specific finding though, is an elevated anti-citric citrullinated peptide antibody shown here at 84 u/ML. ESR being elevated at 55.
Again, a lot of different things could do that and the CRP is also elevated.
Moving farther to the right our ANA 1:80, that's a very non-specific finding.
The specificity of that is "nl" for identifying any condition, especially in an elderly or middle aged gentleman.
And importantly, the anti-double stranded DNA antibody is negative which essentially is gonna help us to take lupus off the differential.
If somebody is having a lupus flare with active synovitis.
their ANA should definitely be considerably higher and you'd hope to have a positive anti-double stranded DNA antibody as well.
So, let's talk about the radiographic findings.
So looking at plain films of the hands and wrists, we can see some soft tissue swelling of the wrists,
symmetric joint space loss of several MCPs, and subtle subchondral erosions of the right scaphoid and MCPs.
Now, early rheumatoid arthritis could definitely be characterized by subtle subchondral erosions.
So can psoriatic arthritis however, the one thing that we wouldn't really see erosions for would be lupus, for example.
Looking at all of this information combined, particularly the elevated anti-CCP and the negative findings for gout and lupus, etc.,
I think we can confidently say that we've got a case of rheumatoid arthritis.
So, let's review some additional features of this case that just highlights some other aspects of treatment and care for rheumatoid arthritis patients.