Rheumatoid Arthritis (RA) Flashcards
Define Rheumatoid Arthritis (RA).
A chronic, systemic, inflammatory AUTOIMMUNE disorder of the synovial joints, causing a SYMMETRICAL POLYARTHRITIS
Describe the epidemiology of RA.
- 2 to 3 times more common in women.
- Approximately 1% of the population affected.
- Prevalence increased in smokers.
Describe the usual onset of RA.
Aged 30-50.
Rapid, within a year.
Describe the aetiology of RA.
Auto-antibodies e.g. RF and anti-CCP lead to a defective cell mediated immune response.
Give 5 risk factors for RA.
- Gender
- Women - especially pre-menopausal = risk 3x greater (suggests role of sex hormones - oestrogen?) - FHx
- Genetics
- HLA DR4 (a gene often present in RF positive patients)
- HLA DR1 (a gene occasionally present in RA patients) - Smoking
- Obesity
Describe the disease process behind RA.
- Chemoattractants in the joint recruit inflammatory cells
- B/T cells + neutrophils infiltration
- Production of cytokines (IL-1,2,4,6,8 + TNF-a) by T cells = inflammation.
- Overproduction of TNF-a
- Synovitis -> proliferation -> pannus formation -> pannus destroys articular cartilage and subchondral bone.
= inflammation at the synovial membrane
= damage to soft tissue and cartilage
= damage to bone
Give 5 symptoms of RA.
- Early morning + cold-environment stiffness (>60 mins).
- Pain that eases with use.
- Swelling.
- Systemic symptoms e.g. fatigue, weight loss, flu like illness, muscles aches + weakness
- Extra-articular involvement.
Describe the character of the pain from RA.
Morning stiffness >60 mins.
Pain is accompanied by stiffness.
Give 5 signs of RA.
- Symmetrical.
- Deforming.
- Polyarthropathy.
- Erosion on X-ray.
- 80% are RF positive.
Describe the pattern of joints affected by RA.
Symmetrical.
Small and large joints on both sides.
>3 affected, hands usually involved.
What joints tend to be affected in RA?
- MCP.
- PIP.
- MTP.
- Wrist.
Give 5 key signs in the hands for RA.
- Z shaped deformity to the thumb
- Swan neck deformity (hyperextended PIP with flexed DIP)
- Boutonnieres deformity (hyperextended DIP with flexed PIP)
- Ulnar deviation of the fingers at the knuckle (MCP joints)
- Piano key deformity of the wrist
Which joint is almost never affected in RA?
Distal interphalangeal joints (DIP)
- If you come across enlarged painful distal interphalangeal joints, this is most likely to be Heberden’s nodes due to osteoarthritis.
If you were examining the hands of someone with RA, give 5 things you might expect to see.
- DIP not affected
- Hurts to squeeze the joints
- Joints are warm
- Ulnar deviation
- Cannot make a fist
- Z thumb
- Swan neck deformity
What systemic features are present in RA?
- Elbow and lung nodules
- Vasculitis
- Pericarditis
- Carpal tunnel
- Sjorgen’s
- Raynaud’s
- Lymphadenopathy
- Fever, myalgia, malaise, fatigue
RA extra-articular involvement: describe the effect on soft tissues.
- Nodules.
- Bursitis.
- Muscle wasting.
RA extra-articular involvement: describe the effect on the eyes.
- Dry eyes.
- Scleritis (severe pain, can’t look at bright lights)
- Episcleritis (non severe mild redness of eyes)
RA extra-articular involvement: describe the neurological effects.
- Sensory peripheral neuropathy.
- Entrapment neuropathies e.g. carpal tunnel syndrome.
- Instability of cervical spine.
RA extra-articular involvement: describe the haematological effects.
- Palpable lymph nodes.
- Splenomegaly.
- Anaemia.
RA extra-articular involvement: describe the pulmonary effects.
- Pleural effusions
- Fibrosing alveolitis
- Pneumoconiosis (Caplan’s syndrome, especially in miners)
- Pulmonary nodules, pulmonary fibrosis
- Interstitial lung disease
- Bronchiectasis