rheumatoid arthritis

Question 1

definition of RA

Answer 1

Rheumatoid arthritis (RA) is a chronic inflammatory condition affecting around 1% of the population, making it the most common inflammatory arthritis seen by physicians.[1] It primarily affects the small joints of the hands and feet and, if not treated aggressively, can be a major cause of work loss, decreased quality of life, need for joint replacement surgery, and mortality.[2] RA is a clinical diagnosis; laboratory and radiographic tests help to confirm the diagnosis and provide useful prognostic information.

Question 2

epidemiology

Answer 2

Patients are usually in their 50s when diagnosed and there is a slight female preponderance.[1] In younger patients, females have a 2:1 predominance but as age increases this becomes closer to 1:1.

Question 3

signs and symptoms

Answer 3

• active symmetrical arthritis lasting more than 6 weeks
• joint pain and swelling (most commonly MTP, PIP and MCP joints)
• morning stiffness of more than 1h (usually sign of inflammatory disease)
• boutonniere’s deformity
• swan neck deformity
• ulnar deviation
• rheumatoid nodules
• vasculitic lesions/skin rash (severe disease)
• pleuritic chest pain (severe disease)
• scleritis/uveitis (severe disease)

Question 4

risk factors

Answer 4

• genetic predisposition (family history)

- smoking

Question 5

investigations

Answer 5

• rheumatoid factor
• anti CCP antibody
• radiographs => erosions
• ultrasonography => synovitis of wrist and fingers

Question 6

criteria for diagnosis

Answer 6

American College of Rheumatology (ACR)/European League Against Rheumatism (EULAR) collaborative initiative 2010 rheumatoid arthritis classification criteria[18]
Any patient with six or more points after the criteria have been applied is considered to have RA. Before the criteria can be applied, patients need to have at least one joint with synovitis, and other reasons for it need to be ruled out.

Joint distribution:
1 large joint - 0 points
2-10 large joints - 1 point
1-3 small joints (large joints excluded) - 2 points
4-10 small joints (large joints excluded) - 3 points
>10 joints (at least 1 small joint) - 5 points.
Serology

Negative rheumatoid factor (RF) and negative anti-cyclic citrullinated peptide (anti-CCP) antibodies - 0 points
Low positive RF or anti-CCP antibodies (≤3 x upper normal limit) - 2 points
High positive RF or anti-CCP antibodies (>3 x upper normal limit) - 3 points.

Symptom duration:
<6 weeks - 0 points
≥6 weeks - 1 point.
Acute-phase reactants

Normal CRP and erythrocyte sedimentation rate (ESR) - 0 points
Abnormal CRP or ESR - 1 point.