Historically also known as "Reiter syndrome"
Seronegative spondyloarthropathy that manifests as an acute, asymmetric, oligoarthritis (LE>UE) that occurs 2-6 weeks after infection
Patients often positive for HLA-B27
Associated with bacterial infections
Shigella, Salmonella, Campylobacter, Chlamydia, etc.
Classic triad: urethritis, conjunctivitis, and arthritis ("Can't pee, can't see, can't climb a tree")
Shigella, Salmonella, Campylobacter, Chlamydia, etc.
Reactive arthritis
Acute osteoarthritis
Rheumatoid arthritis
Avascular necrosis
Juvenile idiopathic arthritis
Crystal-induced 
Reactive poststreptococcal arthritis
Gonococcal arthritis, arthritis-dermatitis syndrome