Group B streptococcal facet joint arthritis: case report.

Study Design. Case report. Objective. To report a previously undescribed complication of group B streptococcal infective endocarditis, which was lumbar facet joint arthritis. Summary of Background Data. Lumbar facet joint arthritis is a rare clinical condition, and the casual pathogen is generally Staphylococcus aureus. Streptococcus agalactiae usually causes peripartum infections affecting the mother and newborn. It rarely causes infective endocarditis, and facet joint arthritis has never been reported before. Methods. A case of group B streptococcal infective endocarditis and lumbar facet joint arthritis is described. The clinical course, treatment, and complications of facet joint arthritis and infective endocarditis are discussed. Results. A nonimmunocompromised patient presenting with fever and back pain was diagnosed to have S. agalactiae bacteremia. Subsequent imaging with echocardiography revealed mitral valve infective endocarditis and magnetic resonance imaging of lumbar spine showed left L5–S1 facet joint arthritis. Emergent intravenous antibiotic treatment and mitral valve replacement resulted in complete resolution. Conclusions. Facet joint septic arthritis should be considered in the differential diagnosis of patients presenting with fever and back pain. S. agalactiae should also be considered among the causal pathogens, and, if present, emergent antibiotic treatment, follow-up for complications, and a thorough search for the source of the hematogenous spread, which can be a life-threatening infection, are essential.