Acute Inflammatory Arthritis

Today we discussed a case of acute oligoarticular inflammatory arthritis.  In thinking about the initial differential we discussed spondyloarthropathies (Reactive arthritis, ankylosing spondylitis, IBD and psoriatic), Lyme, disseminated gonorrhea and as there were only 2 joints involved we also discussed the monoarticular arthritis including septic, gout and pseudogout. 

  1. What is the synovial joint analysis that can rule out septic arthritis.  From JAMA rational clinical exam we can find the positive LR based on the WBC count.

2.  Can check point inhibitors cause inflammatory arthritis?  A recent article in Ann Rheum Dis found that 9 of 13 patients developed inflammatory arthritis while on nivolumab and ipilimumab. 

3.  What are the side effects to monitor for while on check point inhibitors? We used a great pneumonic to help us remember the large categories of adverse effects caused by these medications: LLEGS;  Lungs, Liver , Endocrinopathies, GI, Skin.