Thread by @AndreMansoor

1/10
A 26 y/o woman presents with migratory arthritis. Started with a red and hot foot/ankle. Then went to the knee. Overuse, she was told. When ice/rest did not help, she went to the hospital.

An arthrocentesis procedure was performed.

2/10
20K white blood cells but no organisms. She was taken for a washout procedure for presumed septic arthritis.

And when the knee didn't improve, she was taken for another one.

And when she still didn't improve, she was transferred to our hospital.

3/10
We consult our framework for arthritis.

4/10
Inflammatory arthritis is suggested by the cardinal physical findings of inflammation: erythema (rubor), warmth (calor), pain (dolor), and swelling (tumor).

As seen in this elbow joint from another patient:

5/10
Our patient has inflammatory arthritis. Next we think about the number of joints that are involved.

6/10
There are 2 joints involved, putting us in the category of oligoarticular arthritis, which helps to focus our differential diagnosis.

Now we can seek hypothesis-driven information from the history and the exam.

7/10
One of our hypotheses leads us to examine her fingernails.

What is this finding?

8/10
We were looking for nail bed pitting but instead find what looks like a drop of oil.

Ah, the oil drop sign.

So we perform a full skin examine and the following findings were hiding on the nape of the neck (had to lift up her hair to see it) and the back of her ear:

9/10
There are several spondyloarthritides, among them psoriatic arthritis.

Patient was started on methotrexate and etanercept, with subsequent resolution of symptoms.

10/10
This patient went through several unnecessary surgical procedures.

Physical exam plays a critical role in diagnosis.

For more on this patient: link.springer.com/article/10.100…

For more cases: physicaldiagnosispdx.com/case-presentat…

Source of arthritis framework: amazon.com/Frameworks-Int…