Polymyositis + dermatomyositis

Question 1

Define myositis

Answer 1

striated muscle inflammation and degeneration

Question 2

Two features of myositis

Answer 2

Progressive symmetrical proximal muscle weakness
Dysphagia
Respiratory weakness
Dysphonia

Question 3

Wasting of which two muscular areas are most common in polymyositis?

Answer 3

shoulder and pelvic girdle

Question 4

Define dermatomyositis

Answer 4

= myositis + skin signs

Question 5

List two skin signs of dermatomyositis

Answer 5

 Heliotrope rash on eyelids ± oedema
 Macular rash (shawl sign +ve: over back and shoulders)
 Nailfold erythema
 Gottron’s papules: knuckles, elbows, knees
 Mechanics hands: painful, rough skin cracking of finger
tips

Question 6

Two extra-muscular and derm features of polymyositis

Answer 6

fever
arthritis
pulmonary fibrosis
raynaud's
myocarditis, arrhythmias

Question 7

What might you be worried about in patient with myositis?

Answer 7

malignancy

Question 8

Name one muscle enzyme that would be raised in myositis

Answer 8

CK- creatine kinase, raised in thousands!!!!

Question 9

Two investigations for myositis

Answer 9

Screen for malignancy (CXR, tumour markers, CT…)
Muscle enzymes
Muscle biopsy
Abs

Question 10

Two differentials for myositis?

Answer 10

Muscular dystrophy
Polymyalgia rheumatica
Drugs

Question 11

Name two drugs that cause similar symptoms seen in myositis

Answer 11

statins

steroids

Question 12

What do gottron’s papules look like and where are they located?

Answer 12

red.purple papules over MCP/PIPJ

Question 13

What is the treatment of myositis?

Answer 13

corticosteroids, immunosuppression, IV immunoglobulins, rituximab and cyclophosphamide in resistant disease