Polymyositis and Dermatomyositis Flashcards
What are polymyositis and dermatomyositis?
Autoimmune disorders in which muscles become inflamed due to chronic inflammatory cells, usually idiopathic
_______ of DM/PM patients experience pain.
Half
Early symptoms include _____________.
proximal weakness of muscles in the extremities
The skin symptoms of dermatomyositis and polymyositis include __________.
Gottron’s papules (erythematous nodules on the fingers), periungual erythema, heliotrope rash (blue around the eyes), V and shawl sign (erythema on the shoulders, back, and anterior chest), and poikiloderma (mottling on the thighs)
List some of the extra-muscular manifestations of DM/PM.
Fatigue, weight loss, fever, dysphagia, intestinal perforation, pulmonary fibrosis, myocarditis, and Raynaud’s
Typical age of presentation is _________.
either in childhood or fifth decade
Lab values suggestive of DM/PM are ________.
elevated CPK (creatine phosphokinase), myoglobinemia, AST, ALT, LDH, and aldolase
20% of patients have ____________.
antibodies to Jo-1 (which is the aminoacyl t-RNA synthetase for histidine)
Less common than anti-Jo1, patients sometimes have __________.
antibodies to DNA helicase or signal-recognition particle
Nonspecific to DM/PM, patients can have antibodies to _________.
DNA
EMGs (electromyographies) will demonstrate ___________, while MRIs can show ________.
myopathic findings; edema and muscle inflammation
Histologically, polymyositis is characterized by ____________.
CTLs and macrophages throughout the fascicle
DM is histologically characterized by _________.
perivascular accumulation of CD4s, macrophages, and dendritic cells
What is some of the evidence for viral induction of DM/PM?
Higher antiviral antibodies in those with DM/PM, virus DNA detected in muscles of those with DM/PM, response suggestive of antiviral response
Treatment is directed at ___________.
treating the inflammation and suppressing the immune system
