Infectious Arthritis Differential Diagnosis

Differential Diagnosis

The following diseases should be ruled out in the diagnosis of infectious arthritis:  

• Crystal-induced arthritis (eg gout and pseudogout): A recurrent monoarthritis, podagra and tophi are highly predictive of gout. The definitive diagnosis is through demonstration of characteristic urate crystals in the synovial fluid. Crystal-induced arthritis and infectious arthritis may co-exist
• Exacerbations of rheumatoid arthritis and osteoarthritis
• Chronic inflammatory diseases (eg Reiter’s syndrome, ankylosing spondylitis, inflammatory bowel disease associated arthritis, collagen vascular disease and spondyloarthritis)
• Osteomyelitis
• Lyme disease: The arthritis develops weeks-months after the rash and fever of Lyme disease. A confirmation is done via Western blot
• Rheumatic fever
• Reactive arthritis from bacterial, viral or parasitic infections
• Bursitis/cellulitis
• Trauma, hemarthrosis, neuropathic arthropathy