Differential Diagnosis of Acute Arthritis Crystal-induced arthritis: Calcium oxalate, gout, cholesterol, pseudogout, hydroxyapatite crystals Infectious arthritis: Bacteria, fungi, mycobacteria, spirochetes, viruses Inflammatory arthritis: Behçet syndrome,* rheumatoid arthritis,* sarcoid, systemic lupus erythematosus,* Still disease,* seronegative spondyloarthropathy (e.g., ankylosing spondylitis, psoriatic arthritis, reactive arthritis, inflammatory bowel disease–related arthritis), systemic vasculitis* Osteoarthritis: Erosive/inflammatory variants* Other: Amyloidosis, avascular necrosis, clotting disorders/anticoagulant therapy, familial Mediterranean fever,* foreign body, fracture, hemarthrosis, hyperlipoproteinemia,* meniscal tear Systemic infection: Bacterial endocarditis, human immunodeficiency virus infection Tumor: Metastasis, pigmented villonodular synovitis #Diagnosis #Differential #Acute #Arthritis #Monoarticular #Septic
