Rheumatoid Arthritis and Spondyloarthropathies

Rheumatoid arthritis (RA) is a chronic systemic inflammatory disease characterized by symmetrical synovitis, morning stiffness, and joint destruction. It affects 0.03% to 1.5% of the population worldwide. Women are affected 3 times more frequently than men. Its incidence peaks between the ages of 50 and 75 years. Lifetime risk of RA in adults is 3.6% for women and 1.7% for men. The presentation of an unknown antigen to a genetically susceptible person is believed to trigger RA.