Polymyositis Flashcards
1
Q
what is polymyositis?
A
inflammatory disorder causing symmetrical, proximal muscle weakness
2
Q
what is polymyositis caused by?
A
T-cell mediated cytotoxic process directed against muscle fibres
3
Q
what is polymyositis associated with?
A
- connective tissue disorders
- malignancy
4
Q
what is dermatomyositis?
A
- variant of polymyositis
- skin manifestations are prominent = purple (helitrope) rash on the cheeks and eyelids
5
Q
what is the aetiology of polymyositis?
A
- middle aged
- females
6
Q
what are the features of polymyositis?
A
- proximal muscle weakness +/- tenderness
- raynauds
- respiratory muscle weakness
- interstitial lung disease
- dysphagia, dysphonia
7
Q
what is a sign of poor prognosis in polymyositis?
A
interstitial lung disease
e.g. fibrosing alveolitis or organising pneumonia
8
Q
what investigations are done in polymyositis?
A
- elevated creatinine kinase
- LDH, aldolase, AST and ALT (muscle enzymes) are elevated
- EMG
- muscle biopsy
- autoantibodies
9
Q
what autoantibodies are seen in polymyositis?
A
- anti-synthetase
- anti-Jo-1 can be seen in disease associated with lung involvement, raynauds and fever
10
Q
what is the management of polymyositis?
A
- high-dose corticosteroids
- azathioprine may be used as a steroid-sparing agent
11
Q
what clinical picture should raise your suspicion of polymyositis?
A
proximal muscle weakness + raised CK + no rash
