Lyme arthritis: a comparison of presentation, synovial fluid analysis, and treatment course in children and adults.

Objective: This case series examines differences in the presentation, management, and outcome of Lyme arthritis between the pediatric and adult population.

Methods: We reviewed charts of pediatric and adult patients evaluated for Lyme arthritis by rheumatologists and pediatric infectious disease specialists in Portland, Maine between January 2002 and July 2008. Patients included for analysis had documented joint swelling and positive Lyme serology. Data on clinical presentation, synovial fluid and peripheral blood results, treatment, and clinical course were analyzed.

Results: Twenty-nine adults and 52 children met case criteria for Lyme arthritis. Children were more likely than adults to present acutely (P < 0.0001) and also had higher mean peripheral blood (P = 0.05) and synovial fluid white blood cell counts (P < 0.0001). Lyme arthritis was more frequently suspected in children at presentation (P = 0.04). There was no difference between children and adults with respect to suspicion for septic arthritis, hospitalization, or surgical intervention. Adults received more antibiotic courses (P = 0.007) and were more likely to have intravenous antibiotics in subsequent treatment courses (P = 0.006). Children were more likely to have normal function within 4 weeks of initiating antibiotic treatment (P < 0.0001).

Conclusion: Children with Lyme arthritis were more likely to present acutely with higher synovial white cell counts than adults. We did not, however, observe a significant difference in hospitalization or surgical management. Children had more prompt resolution of their joint swelling and received less treatment overall.