Metabolic (ie, gout, pseudogout, hemochromatosis)
Endocrine (ie, acromegaly)
Degenerative (ie, osteoarthritis)
Infectious (ie, septic joint, infectious synovitis, rheumatic fever)
Connective tissue disorders (rheumatoid factor-positive) (i.e, systemic lupus erythematosus, rheumatoid arthritis, progressive systemic sclerosis/scleroderma, polymyositis/dermatomyositis)
Inflammatory vasculitides (ie, polyarteritis nodosa, Wegener's granulomatosis, hypersensitivity vasculitis, giant cell arteritis)
Seronegative spondyloarthropathies (rheumatoid factor-negative) (ie, ankylosing spondylitis, Reiter's syndrome, psoriatic arthritis, inflammatory bowel disease)