Case 14 Rheumatology

Migratory Arthritis

Work it one clue at a time. The diagnosis stays hidden until you reveal it.

Clue 1

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.

Clue 2

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

We consult our framework for arthritis.

Clue 3

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:

Clue 4

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

Clue 5

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.

Clue 6

One of our hypotheses leads us to examine her fingernails. What is this finding?

Clue 7

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.

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Clue 8

Rheumatology_psoriasis_plaques_psoriatic_arthritis1

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Clue 9

Rheumatology_psoriasis_plaques_psoriasis

There are several spondyloarthritides, among them psoriatic arthritis. Patient was started on methotrexate and etanercept, with subsequent resolution of symptoms.

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