Bilateral Knee Lyme Arthritis in Children

Abstract

Cases: Three patients presented with bilateral knee pain, effusion, decreased range of motion, and difficulty ambulating.Synovial analysis demonstrated leukocytosis in bilateral knees with positive serum enzyme-linked immunosorbent assay. All cases were managed with antibiotics and anti-inflammatories. One patient developed chronic Lyme arthritis and underwent arthroscopic synovectomy. Conclusion:Bilateral knee arthritis is a possible presentation of Lyme disease in children. Accurate diagnosis and treatment with antibiotics and anti-inflammatories can lead to satisfactory outcomes. Arthroscopic synovectomy may be indicated if conservative treatment fails.L yme arthritis is a common manifestation of late-stage infection from the spirochete Borrelia burgdorferi. Lyme disease afflicts approximately 476,000 people annually in the United States 1-4 . Diagnosis is difficult because arthritis may be the sole presenting feature 2 . In Lyme-endemic areas, unexplained knee pain and effusion should raise suspicion of Lyme disease 4,5 .Physical examination may reveal large effusions and erythema, often without fever or significant pain to passive range of motion (PROM) and weight bearing 2 . Screening testing includes enzyme-linked immunosorbent assay (ELISA), and confirmatory testing includes the immunoglobulin G western blot. Synovial polymerase chain reaction (PCR) tests for B. burgdorferi DNA may be positive before treatment is administered 2 . The associated synovial white blood cell (WBC) count is typically higher in children and can approach counts observed with septic arthritis (>50,000 WBC), often with polymorphonuclear neutrophil (PMN) predominance 6,7,10 . C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) may also be elevated 6 . Histologically, Lyme arthritis demonstrates synovial hypertrophy, vascular proliferation, and infiltration of mononuclear cells 8 . Matrix metalloproteinases contribute to accelerated cartilage breakdown 8 . Oral or intravenous antibiotics, such as amoxicillin, doxycycline, and ceftriaxone, resolve more than 75% of pediatric Lyme arthritis 2,9-13 . Synovitis may be managed with nonsteroidal anti-inflammatory drugs (NSAIDs), intraarticular steroid injections, or disease-modifying antirheumatic drugs (DMARDs) 2,9 . Patients with synovitis despite medical management may be candidates for arthroscopic synovectomy 2,8,14 .There is a single reported case of bilateral hip Lyme arthritis in an elderly patient 15 and reports of polyarticular involvement in children 16 ; however, this case describes 3 children who presented with isolated bilateral knee Lyme arthritis: 2 acute and 1 chronic.The patients and their parents were informed that data concerning their cases would be submitted for publication, and they provided consent. Case ReportsC ASE 1. A 5-year-old boy presented with bilateral knee pain Disclosure: The Disclosure of Potential Conflicts of Interest forms are provided with the online version of the article (http://links.lww.com/JBJSCC/C89).