286. Rapid, One-Tier Diagnosis for Lyme Arthritis

BACKGROUND: Lyme disease commonly present as arthritis (LA) and may mimic septic arthritis (SA). SA has worse prognosis and requires hospitalization. LA diagnosis guidelines suggest two-tiered algorithm. Results take 3–5 days to return, putting children at risk by mismanagement. For children with acute arthritis, timely recognition improves quality of care. METHODS: We retrieved charts of children with joint complaint in a Lyme endemic region (January 2011–July 2016). We identified SA and LA and characterized presentations. We reviewed all Lyme [anti-VlsE] chemiluminescent immunoassay screens, (January 2015–January 2017). The study was approved by IRB. RESULTS: We reviewed 705 charts. SA was found in 24 patients, including 5 with knee arthritis. Seventy-two had confirmed LA, 70 in the knee [fig 1]. Laboratory and physical findings are summarized in Table 1. 2,341 anti-VlsE screens reviewed. 92% were negative. Of the 88 patients with high levels (>8), 53% had arthritis [Figure 2]. CONCLUSION: In children with knee arthritis, LA is 14 times more common than SA. Delayed diagnosis put many children at risk of mismanagement. Physical and laboratory findings may direct clinical suspicion but are limited when differentiating between LA and SA. High value anti-VlsE screens suggest symptomatic disease and may confirm LA diagnosis within hours. This correlates with the hypothesis of this B. burgdoferi’s surface protein’s role in immune evasion, leading to dysregulated inflammation. DISCLOSURES: All authors: No reported disclosures.