Lyme Arthritis Presenting as Transient Synovitis of the Hip

Abstract

Transient synovitis of the hip is a common cause of hip pain in children. The etiology of transient synovitis of the hip is unknown. Lyme arthritis is characterized by brief, often recurrent episodes of oligoarthritis. Lyme arthritis most often affects a single knee, but hip involvement is uncommon. This report describes 2 children with Lyme arthritis who presented with features of transient synovitis of the hip. Lyme arthritis should be considered in the differential diagnosis of transient synovitis of the hip in children.

Primary Lyme Arthritis of the Pediatric Hip

“…1 In contrast, when facing a patient with a swollen knee, Lyme disease is often considered in the differential diagnosis as 60% to 80% of patients with Lyme disease present with monoarthritis of the knee. 1,2,4,6,15 The typical pattern of joint involvement in Lyme disease is intermittent attacks of swelling and pain in one or more large joints. 16 Joint pain associated with Lyme disease may be a characteristic in 50% to 60% of patients in the chronic stage of disease, which is associated with synovial hypertrophy, joint effusions, and arthralgia.…”

“…1,2,6,15 As many as two thirds of patients may have multiple joints involved, with an average of 2.4 joints involved in a series of 90 pediatric patients. 15 Historically, descriptions of isolated 1,4,8 Rarely, Lyme arthritis may present acutely in the hip and may mimic the diagnosis of septic arthritis. 8 The clinical presentation of Lyme disease has been well described in the pediatric population, yet few studies have identified isolated monoarticular joint involvement.…”

“…1 Lyme disease generally should be considered in the differential diagnosis of septic arthritis, especially of the knee. [1][2][3][4] Hip joint involvement is only described in 5% to 15% of patients with Lyme disease, 2 however, in most of these instances other joints are affected as well. [4][5][6][7] For these reasons, although the diagnosis of Lyme disease may be apparent in certain clinical scenarios, it is not commonly considered in the differential diagnosis of monoarticular hip pain.…”

“…There are only a few case reports describing Lyme disease with isolated hip involvement. 1,4,8 The purpose of this study is to review our experience with primary Lyme arthritis of the hip at a tertiary referral center in a Lyme endemic region.…”

Transient synovitis of the hip: Ultrasound appearance. Mini-pictorial essay

“…The main differential diagnosis is septic arthritis [2] and juvenile rheumatoid arthritis. Also cases of Lyme arthritis of the hip [3] with clinical and imaging characteristics identical to transient synovitis of the hip are described in the literature.…”