inflammatory myopathies Flashcards
1
Q
difference between myalgia and myopathy
A
myalgia - not associated with weakness or raised muscle enzymes
2
Q
features of inflammatory myopathies
A
- muscle weakness
- proximal
- symmetrical
- generally insidious but may progress rapidly
- involvement of resp and pharyngeal muscle - LIFE THREATENING
- peak age 50-60
- may be due to non autoimmune causes
3
Q
what is polymyositis
A
inflammation of striated muscle
4
Q
symptoms of polymyositis
A
-proximal muscle weakness and pain-
often normal distal power
often spares ocular muscles
5
Q
blood findings in polymyositis
A
- raised CK, AST, ALT, LDH, ESR, CRP
- ANA+ve (Jo-1)
6
Q
investigations in polymyositis
A
- electromyography
- MRI - oedema
- muscle biopsy (endomysial infiltrates, lymphocytic CD4+, CD9+ & macrophages)
7
Q
what is dermatomyositis
A
skin and muscle involvement + polymyositis
8
Q
characteristic rashes of dermatomyositis
A
gottrons papules (purple knuckles)/flagellateq
9
Q
muscle biopsy in dermatomyositis
A
- perivascular infiltrate
- muscle fibre atrophy uneven
- lymphocytic infiltrate CD4+
- MHC - class 2 up regulated
