Inflammatory Myopathies Flashcards
(14 cards)
What are the infectious causes of inflammatory myopathies?
• Bacterial infections
• Viral infections (influenza, coxsackie, HIV)
• Parasitic infections (Trichinella spiralis, cysticercosis)
What are the non-infectious immune-mediated inflammatory myopathies?
Polymyositis
dermatomyositis
inclusion body myositis (in older patients)
What characterizes polymyositis and dermatomyositis?
Immunologically mediated muscle injury with inflammation
What type of immune injury occurs in dermatomyositis?
Antibody-mediated tissue injury
What type of immune injury occurs in polymyositis?
Cytotoxic T-cell-mediated injury
What type of diseases are polymyositis and dermatomyositis associated with?
Autoimmune diseases
What are the clinical features of polymyositis and dermatomyositis?
Symmetric muscle weakness initially affecting large muscles of trunk, neck, and limbs
What is a skin manifestation of dermatomyositis?
Skin rash on the eyelids
In which age groups does dermatomyositis occur?
Children (isolated cases), adults (paraneoplastic cases)
Where is lymphocytic infiltration found in polymyositis?
Endomysium
Where is lymphocytic infiltration found in dermatomyositis?
Paraseptal areas
What type of inflammation is seen around blood vessels in dermatomyositis?
Perivascular inflammation
What histological changes are common in polymyositis and dermatomyositis?
Degenerated and regenerating muscle fibers
