Dermatomyositis + Polymyositis Flashcards
1
Q
What are dermatomyositis + polymyositis?
A
Rare idiopathic autoimmune muscle disease
Characterised by inflammation of striated muscle (myositis)
Causing proximal muscle weakness
2
Q
Cause of dermatomyositis + polymyositis
+ trigger
A
- caused by underlying cancer
- (they are paraneoplastic syndromes)
- viral infection can be trigger
3
Q
Presentation of dermatomyositis
A
- gradual onset, symmetrical, proximal muscle weakness
- difficulty standing from chair, climbing stairs
- muscle pain possibly
- gottron lesions
- Periorbital oedema
- photosensitive erythematous rash
- heliotrope rash
- SOB
4
Q
What is gottron lesion?
A
Scaly erythematous patches on knuckles, elbows + knees
5
Q
What is a heliotrope rash?
A
Purple rash on face + eyelids
6
Q
Presentation of polymyositis
A
Gradual onset, symmetrical, proximal muscle weakness
7
Q
Diagnostic criteria of dermatomyositis + polymyositis
A
- symmetrical proximal muscle weakness
- raised creatine kinase
- typical electromyographic changes
- biopsy evidence of myositis
- typical dermatomyositis rash
. - DM if rash + 2 or more of above
- PM if 3 or more of above
8
Q
Investigations of dermatomyositis + polymyositis
A
- creatine kinase
- LFT: raised ALT + normal liver enzymes
- antibodies: anti-Jo 1
- MRI
- normal inflammatory markers
9
Q
Management of dermatomyositis + polymyositis `
A
- high dose corticosteroids first line
- assess for underlying cancer
- PT + OT
- long term: methotrexate or azathioprine
- sun protection in DM
10
Q
Antibodies in dermatomyositis + polymyositis
A
Anti Jo-1 antibodies
