Inflammatory muscle disease Flashcards
What is polymyositis
Chronic inflmmation og striated muscle
What is dermatimyositis
A form of muscle and skin inflammation
How do DM and PM arise
Muscle fibres infiltrated by inflammatory cells, subsequent degeneration, necrosis and phagocytosis.
In PM, mainly cytotoxic t cell damage. In DM, complement mediated damage of intramusclular vasculature
What are the features if the myositis associated with PM and DM
Insidious, painless, symmetrical and proximal muscle weakness
What are the cutaneous features of DM and PM
Grotton papules on hands, helitrope rash on eyelids, macular erethemous rash on face
What re the serological investigations for PM or DM
Creatine kinase or other muscle proteins
Positive autoantibodies
What would an EMG show in DM/PM
Weakness due to myopathic process. Does not show specific diagnosis
WHat does a biopsy show for these
Typical infiltrate pattern of DM or PM
How does MRI help
Identifies areas of anatomical muscle oedema to target a biopsy
How are PM/DM managed
STeroids/steroid sparing agents as creatine kinase and muscle strength is monitored to fall.
Immunosupression
What is polymyalgia rheumatica?
A clinical syndrome of middle aged and eldery characterised by pain and stiffness in neck, shoulder, and pelvic girdles. Small doses of corticosteroids can have a big effect.
Bilateral/symmetrical symptoms, stiffness, muscular pain diffuse, steroid therapy 2 yrs, systemic features like low grade fever, high inflammatory markers
WHat is giant cell arteritis
A vasculitis commonly accompanying PMR, early recognition and treatment can prevent blindness anf other complications due to occulsion or rupture of arteries
Wide symptom range including headaches jaw claudication, loss of vision, scalp tenderness.
Temporal and occipital arteries may be thickened, tender, reduced pulsation, may be clearly visible
