18.4 - Skeletal muscle Flashcards
the presence of dermatomyositis could reveal what underlying pathology?
carcinoma
what are the clinical features of dermatomyositis?
- bilateral proximal muscle weakness
- rash of upper eyelids (heliotrope), OR malar
- red papules on elbows, knuckles, knees (Gottron papules)
what are Gottron papules? in which condition are they seen?
- red papules on elbows, knuckles, knees (Gottron papules)
- dermatomyositis
what are the lab findings in dermatomyositis?
- increased CK
- positive ANA and anti-Jo antibody
- perimysial inflammation (CD4 T cells) with perifascicular atrophy
what is the hallmark autoantibody of dermatomyositis?
anti-Jo
- bilateral proximal muscle weakness (pt cannot comb their hair, walk up stairs)
- rash of upper eyelids, or malar rash
- red papules on elbows, knuckles, knees
diagnosis?
dermatomyositis
anti-Jo antibody is the hallmark autoantibody in what disease?
dermatomyositis
what are the biopsy findings in dermatomyositis?
- perimysial inflammation (CD4 T cells)
- perifasciular atrophy
BIOPSY FINDINGS:
- perimysial inflammation (CD4 T cells)
- perifasciular atrophy
diagnosis?
dermatomyositis
what are the biopsy findings in polymyositis?
- endomysial inflammation (CD8 T cells)
- necrotic muscle fibers
BIOPSY FINDINGS:
- endomysial inflammation (CD8 T cells)
- necrotic muscle fibers
diagnosis?
polymyositis
in x linked muscular dystrophy, skeletal muscle is replaced by __________
adipose tissue
duchenne muscular dystrophy is due to a ____________ (deletion / mutation) in the ____________ gene
- deletion
- dystrophin
what is the typical cause of death in duchenne muscular dystrophy?
cardiac or respiratory failure
becker muscular dystrophy is due to a ____________ (deletion / mutation) in the ____________ gene
- mutation
- dystrophin
