What is Dermatomyositis?

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

What is the skin findings of Dermatomyositis?

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

What are the non-skin features of Dermatomyositis?

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

What is the most common antibody found in Dermatomyositis?

(around 80%) are ANA positive

What is Dermatomyositis often associated with?

connective tissue disorders or underlying malignancy