Rheumatoid arthritis

1. What is the definition of RA?
*2. What is a pannus?
3. What is the prevalence and age range of RA?
4. What is the pattern of onset for RA?

Answers:
1. RA is a systemic autoimmune inflammatory disorder resulting in chronic, symmetric erosive synovitis.
2. Pannus is a membrane of granulation tissue that covers the articular cartilage at joint margins containing fibroblasts that destroy periarticular bone and cartilage. It is the most destructive element in RA.
3. 1% of population, 2x as common in females. Age 20-60 years, peak in 4th and 5th decades.
4. Most have insidious onset over weeks to months with fatigue, malaise, morning stiffness, msk pain usually symmetric, and low grade fever.