Polymyositis + dermatomyositis

Question 1

What is polymyositis?

Answer 1

inflammation mainly of the endomysium of skeletal muscle

Question 2

How does polymyositis present?

Answer 2

myalgia + arthralgia
dysphagia
dysphonia
rest weakness

Question 3

What is dermatomyositis?

Answer 3

inflammation mainly of the perimysial muscle (sheath of connective tissue grouping muscle fibres into bundles)

Question 4

What are the clinical features of dermatomyositis?

Answer 4

Symmetrical proximal muscle weakness
macular rash
lilac purple rash on eyelids often w oedema
Nailfold erythema
Gottrons papules - rough red papule over knuckles

Question 5

What is a pathognomonic of dermatomyositis?

Answer 5

Gottrons papules + raised CK + muscle weakness

Question 6

What are the causes of dermatomyositis?

Answer 6

idiopathic
connective tissue disorders
malignancy - ovarian, breast, lung

Question 7

What is the difference between polymyositis and dermatomyositis in how they present?

Answer 7

skin manifestations aren’t prominent in polymyositis

Question 8

What marker is found in the majority of pts w dermatomyositis?

Answer 8

ANA

Question 9

What is the rx of dermatomyositis?

Answer 9

prednisolone
immunosuppression
cytotoxic
hydroxychloroquine
Tacrolimus (topical) for skin

Question 10

What tests would you do ?

Answer 10

Test for muscle enzymes in plasma - ALT,AST,LDK, CK

Muscle biopsy - DIAGNOSTIC