Lyme Arthritis in Children on the Uptick in Western New York Area

The Importance of Differentiating Oligoarticular Juvenile Idiopathic Arthritis From Lyme Arthritis in Pediatric Patients

Objective This study aims to compare clinical and laboratory features between Lyme arthritis (LA) and oligoarticular juvenile idiopathic arthritis (oligoarticular JIA) by examining several potential predictors in pediatric patients. This study also aims to improve and increase awareness of ways to detect LA and oligoarticular JIA in pediatric patients who present with clinical features of joint pain. Methods A medical chart review was conducted among pediatric patients diagnosed with LA or oligoarticular JIA at John R. Oishei Children's Hospital of Buffalo between January 2014 and September 2018. Patients' diagnoses were identified using the International Classification of Disease 10th Revision code for LA (ICD 10 code A69.23) and oligoarticular JIA (ICD 10 code M08.40). Patients with LA were only included in this study if they (1) exhibited arthritis, (2) tested positive for Lyme antibodies, (3) indicated a positive western blot (WB) of five or more out of 10 Borrelia burgdorferi proteins by IgG antibodies or at least two of three B. burgdorferi proteins by IgM antibodies, and (4) at the age of 16 or below at the time of diagnosis. Patients with oligoarticular JIA were included in this study if they (1) exhibited arthritis affecting one to four joints for at least six weeks in the first six months of diagnosis and (2) are at the age of 16 or below at the time of diagnosis after ruling out LA and reactive arthritis. In this study, clinical presentations, physical exam findings during initial healthcare visits, and demographics including age, sex, and race of patients were obtained. In addition, laboratory results including white blood cells (WBCs), hemoglobin (Hgb), platelet count, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) level, Lyme antibodies through enzyme-linked immunosorbent assay (ELISA) and WB, synovial fluid analysis for red blood cells (RBCs), nucleated cells, and polymerase chain reaction (PCR) for B. burgdorferi DNA were also collected and analyzed. Results In our data, ESR and CRP were significantly higher in LA compared to oligoarticular JIA (P=0.0053 and 0.0005, respectively). The mean WBC in the synovial joint fluid was significantly higher in LA compared to oligoarticular JIA (P=0.002). Conclusion LA shares features with oligoarticular JIA. This overlap prevents the creation of a clinically useful predictive model for LA. Therefore, Lyme testing should be performed on all patients presenting with monoarticular and oligoarticular arthritis. In addition, ESR, CRP, and WBC in the synovial joint fluid were significantly higher in LA compared to oligoarticular JIA in our findings. While this difference is not definitive by any means, it may help distinguish between the two in cases where the diagnosis is not clear-cut, and the values of ESR, CRP, and WBC in the joint aspirate may help guide clinical judgment in cases that lack a definitive diagnosis.

Pediatric unilateral knee swelling: a case report of a complicated differential diagnosis and often overlooked cause

Lyme disease is the most common vector-borne illness in the United States. However, Lyme arthritis is a diagnosis that is often missed, even in children, who are the population with the highest incidence of Lyme disease. Lyme arthritis, which presents in the later stage of Borrelia burgdorferi infection, needs to be recognized and managed promptly, especially in endemic areas or when exposure to ticks is known. We present a case of a 3-year-old female presenting to the emergency department with a history of limping for 2 weeks. The mother of the child recognized a tick bite. However, the child was not taken to seek care expeditiously, because she had not developed any rashes. Test results demonstrated that the patient was IgG positive and IgM negative for Lyme disease, with Western blot confirming the diagnosis of Lyme arthritis. Most patients presenting with Lyme arthritis do not recall having a tick bite, making it difficult to differentiate it from other pediatric conditions. When this diagnosis is missed, it can result in long-term morbidity, which is generally refractory to intravenous antibiotic therapy, oftentimes requiring synovectomy. Hence, this underscores the importance of the consideration of Lyme arthritis as a differential diagnosis in patients presenting with joint effusion.