In this episode, we review reactive arthritis, an inflammatory arthritis that develops days to weeks after a gastrointestinal or genitourinary infection, most commonly associated with Chlamydia trachomatis, Shigella, Campylobacter, or other enteric pathogens. We discuss the immune-mediated pathophysiology involving molecular mimicry and T-cell activation, as well as the association with the HLA-B27 gene. The episode highlights the classic clinical presentation of asymmetric oligoarthritis of the lower extremities, often accompanied by extra-articular features such as conjunctivitis, urethritis, and enthesitis—remembered by the classic mnemonic "can't see, can't pee, can't climb a tree." We also review diagnostic evaluation, including testing for preceding infections and ruling out other inflammatory arthritides, and discuss treatment strategies focusing on NSAIDs, management of the triggering infection, and DMARDs for persistent disease. High-yield clinical pearls reinforce how to recognize this important seronegative spondyloarthropathy in both clinical practice and board-style exams.

References

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