Rheumatoid arthritis Flashcards
What type of arthritis is rheumatoid arthritis?
Sero-positive, inflammatory arthritis
What is rheumatoid arthritis?
Rheumatoid arthritis is an inflammatory autoimmune disorder resulting in a symmetrical inflammatory polyarthritis, affecting mainly the peripheral joints, charaterised by joint pain, swelling and synovial destruction
What are some risk factors for developing rheumatoid arthritis?
- Genetic predisposition - HLA DRB1 and HLA-DR4
- Environmental triggers - Infection and smoking
- Hormonal factors - More common in females (3:1)
- Age - Most common ages 35-50
What structure is mainly affected in rheumatoid arthritis?
Synovium lining the synovial joint capsules and tendon sheaths
What are some examples of synovial joints?
Hand joints
Wrists
Elbows
Shoulder
Knees
Hips
Ankles
feet
Briefly describe the pathophysiology of rheumatoid arthritis
Triggers cause arginine => Citrulline
=> Protein unfolding as no +ve charge
=> Anti-CCP antibodies attack
=> Formation of immune complexes in synovium
=> Infiltration and activation of neutrophils
=> Cartilage degradation and bone erosion
=> Tendonrupture, osteopenia and multi-system disease
How will patients usually present with rheumatoid arthritis?
Pain and stiffness in joints
Symmetrical inflammation of tendon sheaths
What are some basic clinical signs of rheumatoid arthritis?
Reduction in grip strength
Polyarthralgia
Rapid onset
Synovial thickening (Boggy)
Swelling and redness
Prolongued early morning stiffness
Describe the affected joints in rheumatoid arthritis
RA causes symmetrical distal polyarthritis, most commonly affecting the small joints of the hands and feet
What are some hand signs in advanced rheumatoid arthritis?
- Z-shaped deformity (Thumb)
- Swan-neck deformity (Hyper PIP, Flex DID)
- Boutonniere deformity (Hyper DID, Flex PIP)
- Ulnar deviation (Fingers at MCP joints)
What causes Swan neck deformity?
Extensor mechanism imbalance
Describe the histology of rheumatoid nodules
These can be due to necrotising granulomas with macrophages surrounding central collagen necrosis, or synovial herniation, such as Baker’s cysts
What percentage of RA patients will develop rheumatoid nodules?
25%
Where do rheumatoid nodules most commonly form?
Extensor surfaces or sites of frequent mechanical irritation
What is palindromic rheumatism?
This is a condition characterised by self-limiting episodes of inflammatory arthritis, with pain, stiffness and swelling, typically only affecting a few joints
What feature of palindromic rheumatism may suggest progression into RA?
Presence of rheumatoid factor
Presence of anti-CCP
What are some nervous system presentations of rheumatoid arthritis?
Bilateral carpel tunnel syndrome
Raynaud’s phenomenon
Peripheral neuropathy
What are some cardiovascular presentations of rheumatoid arthritis?
Valvular lesions
Pericarditis
Myocarditis
Peripheral oedema
Rheumatoid vasculitis
What are some respiratory symptoms of rheumatoid arthritis?
Interstitial lung disease
Pleuritis
Caplan syndrome
Rheumatoid lung nodules
What are some other systemic presentations of rheumatoid arthritis?
Sjögrens syndrome
Keratoconjunctivitis
Episcleritis
Felty syndrome (Splenomegaly)
Amyloidosis
Myositis
Tenosynovitis
What scoring system is used to classify rheumatoid arthritis?
DAS28 score:
- 2 shoulders
- 2 elbows
- 2 knees
- 2 wrists
- 10 MCPs
- 10 PIPs
1 point is given to each affected joint
How is diagnosis of RA made?
Diagnosis is made using history, clinical examination, inflammatory markers, antibodies and imaging
What antibody has the highest sensitivity and specificity?
Anti-CCP
What antibodies can be tested for in RA?
Anti-CCP
Rheumatoid factor
What will x-ray show in early RA?
Normal tissue
Soft tissue swelling
Periarticular osteopenia
What will x-ray show in late RA?
Erosions
Subluxations
What imaging techniques can be used in RA?
USS
X-ray
MRI (Gold standard)
What are the benefits of USS over X-ray in RA?
US is more sensitive than x-ray for erosions and so is more useful in making treatment changes
What are the benefits of MRI over X-ray in RA?
MRI will clearly show erosions and soft tissue swelling more than x-ray
Why is MRI not first line in diagnosis of RA?
It is very expensive
What is required in treatment of early stage rheumatoid arthritis?
DMARDs
What are DMARDs
Disease modifying anti-rheumatic drugs, which require tight control with a target of remission or low disease activity
What is used in RA if DMARDs are ineffective?
Biologic agents
What are some examples of DMARDs?
Methotrexate
Sulfasalazine
Leflunomide
Hydroxychloroquine
Why are steroids used initially in DMARD treatment?
Most DMARDs take around 3-6 months before their effects begin, so steroids are used as a bridging drug until the DMARDs begin to work, as they cannot be used for long periods of time, due to their side effects
What are some general side effects of DMARDs?
- Bone marrow suppression
- Infection
- Liver function derangement
- Pneumonitis
- Nausea
- Alopecia
What are some unique side effects of methotrexate?
Increased bone marrow suppression
Teratogenic
What are some unique side effects of leflunomide?
Hypertension
Peripheral neuropathy
What are some unique side effects of sulfasalazine?
Orange urine
Male infertility (Reversible)
What are some unique side effects of hydroxychloroquine?
Retinal toxicity
Blue-grey skin pigmentation
Hair bleaching
What is shown in this X-ray?
Soft tissue proliferation
What is shown in this X-ray?
Periarticular osteoporosis caused by hyperaemia in increased vascularity
What is shown in this X-ray?
Inflamed, thickened synovium (Pannus) destroying bone, leading to marginal erosion
What is shown in this X-ray?
Finally, erosion causes bone shortening, so the ligaments and capsule surrounding the joints become lax, with inflammation further softening the ligaments, leading to subluxation and deformity of the fingers
