DERMATOMYOSITIS AND THE LUNG
Callen JP. Dermatomyositis. Lancet. 2000;355(9197):53-7.
Marie I, et al. Interstitial lung disease in polymyositis and dermatomyositis. Arthritis Rheum. 2002;47(6):614-22.
Douglas WW, et al. Polymyositis-dermatomyositis-associated ILD. Am J Respir Crit Care Med. 2001;164(7):1182-5.
Take home points:
1. Dermatomyositis usually presents as proximal muscle weakness and characteristic skin changes
2. Know the skin changes associated with dermatomyositis as this is the key to diagnosis.
3. Approximately 30-40% of patients with dermatomyositis will have ILD; these patients are more likely to
have anti-Jo-1 antibodies and may have a worse prognosis.
What do I need to know about dermatomyositis?
Inflammatory myopathy (proximal muscle weakness) + characteristic skin changes; 25% will have joint
• Characteristic rashes:
− Heliotrope rash: periorbital violaceous/erythematous rash, sometimes assoc. with periorbital edema
− Gottron’s papules: erythema over bony prominences, usually over MCP, PIP, DIP joints
− Shawl sign: poikiloderma (atrophy, dyspigmentation, telangectasias); a photosensitivity rash usually in
a V-shaped distribution around the neck.
− Mechanic hands: rough, dry exfoliating skin on the palms and fingers
• Can be associated with lung involvement (see below) and cardiac involvement (rare)
• Diagnosis is based primarily on clinical findings; muscle biopsy can be helpful as well.
• Anti-Jo-1 antibody is neither sensitive nor specific. Patients with this antibody, however, may have a
worse prognosis and are more likely to have lung disease.
• CK can be elevated as can serum aldolase but these can be normal in the case of Dermatomyositis-sine
myositis (dermatomyositis without muscle weakness or pain).
• Risk of malignancy: approximately 25-40%, increases with age. If your patient has dermatomyositis,
look for malignancy based on age and risk factors. There is a higher incidence of ovarian cancer in
women with derm