SSc - finished Flashcards
Define Systemic Sclerosos
Is an uncommon, multisystem disease of unknown cause, characterised by:
- diffuse fibrosis (sclerosis) of connective tissues
- degenerative changes
- vascular abnormalities
in the skin (scleroderma), articular structures and internal organs
Epidemiology of SSc
3-9 times more common in women
Onset commonly 20-50yoa
Aetiology of SSc
Autoimmune disease
Closely related to SLE
Characterised by the production of ANA’s (specifically nucleolar RNA)
Immune complex deposition in renal and vascular tissues
Pathological processes of SSc in the kidneys
A trigger starts T-cell activation, Macrophage activation and B-cell activity (same as SLE and RA)
The B-cell activation causes the release of autoantibodies, specifically to nucleolar RNA.
Immune complexes deposit in the tissues of the kidney causing glomerulonephritis.
Pathological processes of SSC in the skin
A trigger starts T-cell activation, Macrophage activation and B-cell activity (same as SLE and RA)
The B-cell activation causes the release of autoantibodies, specifically to nucleolar RNA.
Immune complexes deposit in the endothelial cells/ tissues of the small vessels, causing vasculitis.
This causes platelet aggregation and activation as well as narrowing and thickening of small blood vessels, leading to ischaemic tissue injury. The end result of this is fibrosis.
In addition to this, the T-cell activation and macrophage activation cause a release of fibroblasts and chemotactic factors. This results in fibroblast activation. This can then lead to fibrosis.
What is a typical presentation of SSc?
Gradual thickening and induration of skin of fingers
Raynauds phenomenon
Insidious swelling of acral portions of extremities
Polyarthralgia
GRIP
Main organs affected in SSc
Skin: 90% of cases
- Face and fingers usually affected first
- Final result = claw like hands and restricted ROM in face.
GIT: 60% of cases
- Oesophagus and small intestine mostly affected
Kidneys: 60% of cases
Lungs: 20% cases
Heart
Musculoskeletal
What are the skin changes in SSc?
- Epidermal: thinning, shininess, tautness and hyperpigmentation
- Skin adnexal atrophy
- Telangiectasis
- Trophic ulceration
- Dystrophic calcification
What is the progression of SSc disease in the skin?
Progression is as follows:
- skin becomes odematous
- observe vasculitis petechial haemorrhages
- progressive fibrosis involving the dermis and subcutaneous tissue
What are the features of skin in sclerodactyly?
Oedematous Thickened Taut Shiny Inelastic
What are the final outcomes of GIT damage in SSc?
Dysphagia
Reflux oesophagitis
Poor peristalsis
Malabsorption
What are the changes in the kidneys seen in SSc?
- Immune complex deposition in glomerulus results in
- basement membrane thickening
- mesangial hypercellularity
- Intimal fibrosis of small arterioles results, leading to glomerular ischaemia, decrease GFR and eventually renal failure.
What are the changes seen in the lungs in SSc?
Diffuse interstitial pulmonitis leads to diffuse fibrosis and eventually respiratory failure
What are the changes seen in the heart in SSc?
Cor pulmonale (heart failure secondary to pulmonary fibrosis) Myocardial fibrosis
What are the changes seen in the musculoskeletal system in SSc?
Inflammatory synovitis due to lymphocytic and plasma cells infiltrates occuring in the synovium. This results in hypertrophy and hyperplasia of synovial tissue.
In later stages we observe:
- fibrin deposition on the synovial surface which results in frictions rubs over the joints (esp knees), as well as flexion contractures
