Autoimmune connective tissue disease Flashcards
What antibodies are associated with polymyositis and dermatomyositis?
- Anti Jo-1
- Anti Mi-2
What antibody is associated with systemic sclerosis?
Anti-Scl70
Describe Polymyositis and dermatomyositis?
- Proximal skeletal and smooth muscle inflammation
- Autoimmune-mediated
- Myalgia -> dysphagia, dysphonia, respiratory weakness
- Skin involvement in dermatomyositis
Clinical features of PM and DM?
- Symmetrical proximal muscle weakness / pain
- Affect LLs more than ULs
- Difficulty rising from chair, climbing stairs and lifting
- Fever, weight loss, fatigue
What should always be done in polymyositis and dermatomyositis?
Screen for cancer
Describe Dermatomyositis?
- Myositis plus skin signs:
- Rash over back and shoulders
- Discolouration of the eyelid +/- periorbital oedema
- Nail-fold capillary dilation
- Gottron’s papules (rough red papules over knuckles)
- Raynauds
- Rash over back and shoulders
What are the extra-muscular signs in both polymyositis and dermatomyositis?
- Fever
- Arthralgia
- Raynaud’s
- Interstitial lung fibrosis
- Myocardial involvement
Describe the tests for polymyositis and dermatomyositis?
- Creatine kinase can be raised
-
Muscle biopsy (use MRI to identify abnormal muscle for biopsy)
- Confirms diagnosis: Fibre necrosis and inflammatory infiltrate
- Autoantibody associations
- Anti-Mi2, Anti-Jo1
- Electromyography (EMG)
- Can identify non-AI/inflammatory myopathies
- Screen for malignancy
Namr some differentials for polymyositis and dermatomyositis?
- Drugs
- Infection (HIV)
- Rhabdomyolysis
- Muscular dystrophy
- Inclusion-body myositis
- Carcinomatous myopathy
- Endocrine/metabolic myopathy
What drugs can cause polymyositis and dermatomyositis?
- Statins
- Colchicine
- Chloroquine
- Penicillamine
Describe the mangagement of polymyositis and dermatomyositis?
- Prednisolone PO
- Methylprednisolone IV
- If respirsatory/pharyngeal weakness
- Resistant cases:
- Methotrexate + mycophenolate
- Skin predominant disease
- Hydroxychloroquine
Describe systemic sclerosis?
- AI disorder of connective tissue causing:
- Fibrosis of skin, organs and vasculature
- Autoantibodies:
- ANA, anti-centromere
Clinical features of Systemic sclerosis?
- Skin
- Non-pitting oedema of fingers, shiny, taut skin
- Raynaud’s phenomenon
- Arthralgia, tenosynovitis, muscle weakness
- Dysphagia, odynophagia
- Pulmonary hypertension
What is scleroderma?
- Systemic sclerosis without internal organ invovlement
- Tightening and fibrosis of skin
Describe Limited cutaneous systemic sclerosis?
- Raynauds
- Scleroderma of face and distal limbs
- Anti-centromere antibodies
- A subtype of limited systemic sclerosis is CREST syndrome
Treatment for limited systemic sclerosis?
- Sildenafil
- Bosentan
Describe diffuse skin involvement of systemic sclerosis?
- Can involve the whole body
- Anti-Scl70 anitbodies in 70%
- Anti-RNA polymerase in 20%
- Monitor BP and perform regular echos and spirometry
What are the indicators of a poor prognosis in systemic sclerosis?
- Older age
- High ESR
- Proteinuria
- Pumonary HTN
- Diffuse disease
Describe the management of systemic sclerosis?
- No cure
- Raynaud’s
- Avoid cold, thick socks/gloves, sildenafil
- Interstitial lung disease
- Glucocorticoids + cyclophosphamide
- Hypertension
- Regular ACE-i/ARBs
- Pulmonary HTN
- Bosentan, heart-lung transplant
Describe Primary Sjogren’s syndrome?
- Lymphocytic infiltration of salivary and lacrimal glands
- => Glandular fibrosis and exocrine failure
Risk factors for Primary Sjogren’s syndrome?
- 40-60 years
- Female
- HLA-B8/ HLA-DR3
Clinical features of Primary Sjogren’s syndrome?
- Keratoconjunctivitis
- Non-erosive arthralgia
- Enlarged salivary glands
- Raynaud’s phenomenon
Autoantibodies detected in Primary Sjogren’s syndrome?
- Rheumatoid factor
- Antinuclear antibody (ANA)
- Anti-Ro, Anti-La
- Thyroid autoantibody
Describe the diagnosis of Primary sjogren’s syndrome?
- Schirmer tear test
- Normal is >6mm of wetting
- Elevated ESR and hypogammaglobulinaemia
- Positive autoantibody
