Rheuma Case: 37-year-old Woman with Joint Pain

00:00 Alright, I think it's time for our next case.

00:04 Now we've got a 37 year old computer programmer with no significant past medical history who's presenting with joint pain.

00:12 She reports that her left knee began bothering her about 10 days ago, followed by her left ankle a few days later.

00:19 Yesterday morning she woke to new pain in her second and third toes of her right foot and the soul of her left foot.

00:26 The pain in her knee in particular is severe.

00:29 This has never happened to her before.

00:31 She said she's a nonsmoker. Rare alcohol use.

00:34 She's monogamous with her husband of the past 11 years.

00:37 Her aunt has psoriasis review systems reveal some fatigue, low grade fevers, mild low back pain, and she also recalls an episode of diarrhea and low grade fevers for several days.

00:51 But that was about three weeks ago.

00:54 Let's go through our key points on this case thus far.

00:58 The time course definitely sounds acute to sub-acute with an increasing number of problems over the past 10 days, the pattern of joint involvement with left sided symptoms and right sided symptoms involving different joints.

01:11 It's clearly asymmetric and we've got more than one joint so it's oligoarticular Evidence of joint inflammation, a little bit tricky to say until we do a physical exam so we'll hold off on that one.

01:24 Then systemic involvement with the fatigue and low grade fevers.

01:28 We can say that the answer to this one is yes.

01:31 All right. Wow. That's a big list of possibilities for most likely diagnosis.

01:37 We'll have to go through each of them in turn.

01:39 Here's some physical exam and laboratory data.

01:41 First up, she does have a low grade fever to 37.9 degrees Celsius.

01:46 Heart rates, okay, blood pressures, okay.

01:48 She looks utterly worn out.

01:51 No q distress, no lymphadenopathy.

01:53 She's Anicteric and you note a one by one centimeter shallow, painless ulcer in the left buccal mucosa shown here.

02:03 This looks somewhat like an aphthous ulcer which is associated with a variety of autoimmune conditions and in particular the spondyloarthrititides.

02:11 cardiopulmonary exam is benign or abdomen is benign.

02:15 The musculoskeletal exam reveals a hot infusion to the left knee we can definitely say that we have an acutely inflamed joint.

02:23 We also have warmth and swelling to the left ankle tenderness to palpation at the right second and third metatarsophalangeal joints and tenderness to palpation at the medial calcaneal tubercle.

02:34 But there's a lot going on in terms of the lower extremities.

02:38 Let's take a closer look at that medial calcaneal tubercle.

02:41 What we see here in this image on the right is the calcaneus which is the largest bone there on the bottom right of the image.

02:49 At the very bottom is where the plantar fascia inserts.

02:52 You can even see a tiny little calcaneal bone spur they're coming off the calcaneal tubercle.

02:58 Plantar fasciitis is a fairly common disease that we oftentimes see in primary care with folks who are obese and folks who have flat feet and are so called pes planus.

03:08 But it's important to realize that plantar fasciitis is also associated with the spondyloarthritides particularly reactive arthritis and physical exam if you palpate seeing on the image on the far right there on the medial calcaneal tubercle the place circled in the black circle there.

03:25 That is very suggestive of plantar fasciitis.

03:28 Alright, going back to our physical exam looks like there's no evidence of any findings on the skin or on the nails and then reviewing our laboratory data.

03:37 Very mild leukocytosis mild anemia the ESR and CRP are both elevated.

03:43 Importantly, our rheumatoid factor and A.N.A are both negative.

03:48 That's really going to help us to exclude rheumatoid arthritis and exclude lupus.

03:52 Likewise, lyme serologies are negative which is going to steer us away from Lyme disease.

03:57 It looks like we decided to tap the knee that was completely appropriate.

04:01 Our synovial fluid analysis yields 14,000 nucleated cells of note the gram stains negative and there's no crystals.

04:09 Let's talk about what the implication is of those 14,000 nucleated cells.

04:15 You're going to see this a couple times and all these lectures on rheumatology.

04:19 Starting with the left you have non inflammatory conditions moving to rheumatologic, gout and septic arthritis.

04:25 You can see that the range of white blood cells for each category gives you a hint as to what might be going on.

04:31 Our patient has 14,000. So it puts her squarely in the middle of the rheumatologic disease grouping there between two and 20,000.

04:40 Keep in mind that those numbers are not hard and fast.

04:43 You can certainly see some conditions deviate above or below the range.

04:47 That's, that's shown here.

04:51 Now that information which of the following is the most likely diagnosis.

04:56 First with psoriatic arthritis, we really would need to see some evidence of psoriasis as I said 80 to 90% of patients with psoriatic arthritis are going to have some psoriasis first.

05:07 Moreover, such patients tend to have disease of the DIPs, rather than all this stuff going on in the legs so we can safely X that one out.

05:14 Rheumatoid arthritis this is clearly a Seronegative problem.

05:18 Of course, as I mentioned, there are some instances where rheumatoid arthritis is diagnosed despite a negative rheumatoid factor.

05:25 But this patient's symptoms are not chronic.

05:27 Moreover, they're not symmetric we're not again having any involvement of the hands so R.A off the table.

05:34 Systemic lupus erythematosus would not typically be characterized by so much joint problems without any of the other skin manifestations that go along with it.

05:42 But most importantly, a negative ANA essentially takes SLE off the table.

05:47 Lyme disease we already know our serologies are negative so that one's gone and now we'll come back to reactive arthritis in a moment. But septic joint.

05:56 We already saw what the Arthritis and Tisa showed it was only 14,000 White blood cells that'd be very a typical for septic joint, but more importantly you don't get septic joint in a half a dozen joints all at the same time.

06:08 So that's off the list as well Process of elimination, it looks like we've got reactive arthritis.