Flashcards in Rheumatoid Arthritis Deck (22):
What is rheumatoid arthritis?
Seropositive inflammatory condition where the synovial membrane becomes inflamed. HLA DR4 mediated.
Causes of rheumatoid arthritis?
Unknown. Triggers are thought to be stress, infection and cigarette smoking.
Pathogenesis of RA
Trigger causes inflammation of the synovial membrane. An inflammatory pannus (inflamed synovium) forms which attacks and denudes articular cartilage leading to joint destruction. Tendon ruptures and joint instability and subluxation may occur as a result.
How does RA present?
Serum Rheumatoid factor
Rheumatoid nodules on extensor surfaces (in about 25% of patients)
Hand and foot involvement is early- larger joints become affected in advanced disease.
Positive pressure tests of MCP and MTP joints
Long term rheumatic arthritis
Involvement of larger joints e.g. atlas and axial cervical spine.
E.g. atlanto-axial subluxation which can compress the cervical spine
Joints in the hands unaffected by RA
Inflammation of tendon sheath due to synovial inflammation. Can cause trigger finger- jerky movement of finger.
Carpal tunnel syndrome
Compression of the median nerve.
Diagnosis of RA using serological testing
Rheumatoid remains a clinical diagnosis but these tests are used to support it-
Rheumatoid factor- 70-80% specificity.
Anti CCP antibodies-90-99% specific.
Far more specific Can be present for several years without articular symptoms. Related to smoking. Absence of these does not mean absence of disease.
Extra-articular manifestations of RA
Pleural effusions, interstitial fibrosis and pulmonary nodules
Cardiovascular morbidity and mortality are increased in patients with RA.
Ocular involvement is common in individuals with RA and includes keratoconjunctivitis sicca, episcleritis, uveitis, and nodular scleritis that may lead to scleromalacia.
X-ray findings of RA
At the start of the disease- X-ray will probably be normal
They may show peri-articular osteopenia (bone thinning) and periarticular erosions (late in disease)
What may MRI's show in RA?
Soft tissue inflammation
Bone marrow oedema- a forerunner for erosions.
Can distinguish synovitis from effusions.
Can detect erosions earlier.
Ultrasound scans and RA
Increased sensitivity for synovitis in early disease
Very good at detecting erosions (over Xray)
How is the disease activity measured in RA?
Das 28 score.
>5.1 Active disease.
3.2- 5.1 Moderate disease.
2.6-3.2-Low disease activity.
Less than 2.6 Remission
Management of RA
Early recognition and diagnosis
Early treatment with disease modifying anti-rheumatic drugs- suppress the immune system.
NSAIDs and steroids as adjuncts.
patient education and multidisciplinary team involvement.
Treatment pyramid for RA
Aspirin + NSAIDs + DMARD #1
if this doesnt work add DMARD #2
If this doesnt work add DMARD #3
Why use steroids in the treatment of RA?
Improve symptoms and reduce radiological damage.
Not to be used as sole therapy.
IM steroid- 3 injections of 120mg of methylprednisolone every 4 weeks. (if fewer than 5 joints involved)
Could also be given orally.
Name some DMARDs
Hydroxychloroquine-DOES NOT PREVENT EROSIONS.
Combination therapy with MTX,SASP and HCQ.
initial drug of choice in rheumatic arthritis
Start at 15mg a week with rapid escalation.
Maximun dose is 25mg a week
Folic acid 24 hours after MTX dose.
Parenteral MTX has better bioavailability and is better tolerated.
Anchor drug for patients on biologics
Monitoring whilst on DMARDs
Regular monitoring of LFTS,FBC.
Risk of pneumonitis with Methotrexate-Baseline CXR.
Important to discuss with patients regarding teratogenic effects of these drugs.Advise effective contraception.