Reprint of: Lyme arthritis: It’s never too late for joint decision making

A 25-year-old male presented with acute swelling of the left knee consistent with an inflammatory arthritis. He was initially treated with multiple joint aspirations and intra-articular steroid injections followed by disease modifying anti-rheumatic drugs. The patient continued to have escalating flares of inflammatory arthritis over the next 10 months resulting in bony erosions on imaging. Further questioning revealed that he had spent time in upstate New York in the United States two years prior to the onset of the first symptoms. He did not recall any tick bites or erythema migrans rash. The screening Borrelia enzyme linked immunosorbent assay and confirmatory immunoblot IgG were strongly positive on peripheral blood, and Borrelia species DNA was detected in joint fluid. Response to 28 days of oral doxycycline followed by 30 days of intravenous ceftriaxone was unsatisfactory. Following this, anti-TNF treatment (etanercept) was commenced, with an excellent response within 6 weeks. However, this did not completely resolve his synovitis and so after one year is being scheduled for a synovectomy. Lyme arthritis should be considered in the differential of an acutely swollen large joint, especially if there has been travel to endemic areas in the United States.