14. Autoimmune MSK Flashcards
What is sarcoidosis?
Chronic granulomatous disorder of unknown cause. Characterised by T lymphocytes and macrophages driving non-caseating granuloma formation (no necrosis in granulomas).
How does sarcoidosis present?
Fever
Erythema nodosum
Polyarthralgia
Bilateral hilar lymphadenopathy
Pulmonary - dry cough and progressive dypnoea
Extra pulm - organomegaly, uveitis, LUPUS PERNIO, subcut nodules, arrhythmia, symptoms of hypercalcaemia
Investigations for sarcoidsosis?
Increased ESR
Lymphopenia
Hypercalcaemia from high neutrophils
Raised ACE!! Very specific as lung damage
CXR - Stage 1 - bihilar lymphadenopathy 2 - BHL and infiltrates 3. infiltrates alone 4. extensive fibrosis
Biopsy diagnostic
How to treat sarcoidosis?
Conservative
High dose corticosteroids
What is SLE?
Wrongful response to host that causes immune complex formation with poor clearance. Type III hypersensitivity reaction.
Related to HLA-DR3
How does SLE present?
Malar or discoid rash Photosensitive rash Oral ulcers Arthritis Serositis (pleuritis or pericarditis) Renal disorders Neuro disorder Haem
SLE Investigations?
Anaemia, lymphopenia, thrombocytopenia
Raised ESR but normal CRP
ANA, anti-dsDNA and antihistone
C3 and C4 depletion
SLE Treatment?
Maintain with NSAIDS and hydroxychloroquine
Mild - low dose steroids
Moderate - DMARDS
Severe - high dose steroids
What is sjorgren’s syndrome?
Chronic inflammatory disorder characterised by lymphocytic infiltration and destruction of exocrine glands
How does sjorgren’s present?
Keratoconjunctivitis sicca - dry eye Xerostomia - dry mouth Parotid swelling Polyarthritis Raynaud's Vasculitis
Investigations for Sjogren’s?
Schirmer’s test
Autoantibodies - anti-ro and anti-la but not specific
Salivary gland biopsy diagnostic
Treatment for Sjogren’s?
Dry eye - eye drops
Dry mouth - salivary substitutes
Severe disease - immunosuppressants e.g. steroids
What is systemic sclerosis?
Multisystemic autoimmune disease by abnormalities in non-inflammatory bloods vessels, fibrosis of skin and internal organs.
What are the types of systemic sclerosis?
Limited - hands, face and feet
Diffuse - wide spread organ involvement
How does systemic sclerosis present?
Puffy, taut skin with no wrinkles
Renal scleroderma
Pulmonary fibrosis
GI reflux, dysmotility
Investigations for systemic sclerosis
Anti-centromere in limited
Anti-scl-70 and anti-rna polymerase for diffuse
How to manage systemic sclerosis?
Suppress immune system and treat symptoms
What is poly/dermatomyositis?
Rare condition characterised by onset of progressive, symmetrical proximal muscle weakness. Often associated with paraneoplastic phenomena e.g. ovarian cancer
Polymyositis pathology?
Endomysial inflammation with CD8+ T cells
Dermatomyositis pathology?
Perimysial inflammation with CD4+ T cells
How does polymyositis present?
Progressive symmetrical muscle weakness
How does dermatomyositis present?
Gottron’s papules
Facial erythema
Shawl rash
Mechanics hands - dark, thick, irregular patches
How do we investigate poly/dermatomyositis?
Muscle enzymes - CK and aldolase
EMG
Muscle biopsy - inflammation
Autoantibodies - anti-srp, anti-mi2 and anti-jo1
What is giant cell arteritis/temporal arteritis?
Large vessel granulomatous vasculitis of external carotid artery branches
Usually comes hand in hand with PMR