Orthopaedics & Rheumatology\ Rheumatoid Arthritis Flashcards
What is the pathogenesis of rheumatoid arthritis (RA)?
Autoimmune disorder involving chronic inflammation of the synovial lining of joints and destruction of the surrounding joint architecture
RA typically affects what gender and age group of patients?
Females between 30 and 55 years old
What is the typical presentation of RA?
- Pain and swelling of the hands and feet
- fatigue
- morning stiffness
What are the most common joints involved in RA?
- MCP and PIP joints of the fingers
- IP joints of the thumbs
- wrists, MTP joints
Is the typical joint distribution in RA symmetric or asymmetric?
Symmetric
What criteria are used in the diagnosis of RA?
Four of the following seven criteria must be satisfied for diagnosis:
- Morning stiffness for 6 weeks
- Arthritis of three or more joint areas simultaneously for 6 weeks
- Arthritis of hand joints for 6 weeks
- Symmetric arthritis
- Rheumatoid nodules
- Positive serum rheumatoid factor
- Characteristic radiographic changes in the hands
How does a joint affected by RA look on x-ray?
Joint space narrowing and bony erosions
What percentage of patients with RA are RF positive?
85%
What are the classic hand deformities associated with chronic RA?
- Ulnar deviation of the hands
- swan neck or Boutonniere deformities of the fingers
Describe the swan neck deformity.
PIP hyperextension with distal interphalangeal (DIP) flexion
Describe the Boutonniere deformity.
PIP hyperflexion with DIP hyperextension
What are the extra-articular (systemic) manifestations of RA?
- Interstitial lung disease
- pericardial effusions
- ocular manifestations
How is disease activity assessed in a patient with chronic RA?
- Symptoms
- functional status
- degree of joint and extra-articular involvement
- radiographic changes
What laboratory tests are used to follow the degree of synovial inflammation?
- Erythrocyte sedimentation rate (ESR)
- C-reactive protein (CRP) levels
What is the goal of treatment of RA patients?
- Early identification and treatment of active disease to prevent permanent destruction of joints
Describe the effectiveness of analgesics for treatment of RA.
Used for pain control but no effect on disease progression
Describe the effectiveness of NSAIDS for treatment of RA.
Have both analgesic and anti-inflammatory properties but no effect on disease outcome
Describe the effectiveness of Glucocorticoids for treatment of RA
Effective relief of joint pain and inflammation with possible delay of joint erosions
The effectiveness of Disease modifying anti-rheumatic drugs (DMARDs), for example, Methotrexate in the treatment of RA
Decreases disease activity, but limited by side effects
The effectivenss of Antitumor necrosis factor alpha-antibody agents (etanercept, infliximab, adalimumab)
Powerful anti-inflammatory effects
What are the side effects of chronic glucocorticoid use?
- Cushingoid features
- peptic ulcers
- cataracts
- osteoporosis
- hyperglycemia
- hypertension
- immunosuppression
What are the classic cushingoid features?
- Truncal obesity
- buffalo hump
- moon face
- weight gain
How much calcium and vitamin D should patients on chronic glucocorticoids take to help prevent osteoporosis?
- 1000-1500 mg of calcium
- 400-800 IU of vitamin D daily
- by diet or supplementation
What is the mechanism of action of methotrexate?
- Structural analogue of folic acid
- competitively binds to dihydrofolate reductase
- impairing DNA/RNA synthesis and decreasing cellular proliferation
What are the side effects of methotrexate use?
- Hepatotoxicity
- pulmonary toxicity
- myelosuppression
- nephrotoxicity
- aphthous ulcers
If a patient is on methotrexate, how often should you check liver function tests (LFT)?
Every 4-8 weeks
If a patient is on methotrexate, how do you monitor for and help prevent myelosuppression?
- Full blood count (FBC) every 4-8 weeks
- prescribe folic acid 1 mg PO
