Dermatomyositis

Question 1

What is dermatomyositis

Answer 1

inflammatory disorder causing symmetrical, proximal muscle weakness and characteristic skin lesions

Question 2

Causes of dermatomyositis?

Answer 2

• idiopathic
• associated with connective tissue disorders
• underlying malignancy (ovarian, breast, lung)

Question 3

Name the variant of the disease where skin manifestations are not prominent

Answer 3

Polymyositis

Question 4

After a diagnosis of dermatomyositis what must you screen for?

Answer 4

Malignancy

Question 5

Skin features

Answer 5

heliotrope rash in the periorbital region
photosensitive
macular rash over back and shoulder
Gottron’s papules - roughened red papules over extensor surfaces of fingers
dry and scaly hands with linear ‘cracks’ on the palmar and lateral aspects of the fingers
nail fold capillary dilatation

Question 6

Non-skin related features

Answer 6

Proximal muscle weakness +/- tenderness
Raynaud’s
respiratory muscle weakness
interstitial lung disease: e.g. Fibrosing alveolitis or organising pneumonia
dysphagia, dysphonia

Question 7

Most sensitive Antibody found in Dermatomyositis

Answer 7

ANA (80%)

Question 8

Most specific antibody for dermatomyositis

Answer 8

anti-Mi-2 antibodies

Question 9

Investigations used to diagnose dermatomyositis

Answer 9

• elevated creatine kinase
• EMG
• muscle biopsy
• ANA
• anti-Mi-2

Question 10

Management of dermatomyositis

Answer 10

prednisolone