This 60-year-old man developed proximal muscle weakness about 6 months earlier followed by symmetric periorbital erythema and edema(heliotrope), erythematous slightly scaly plaques over the bony prominences, erythematous papules over the knuckles (Gottrons papules)and periungual telangiectasias. Serological analysis revealed a positive ANA and raised creatine kinase levels. Dermatomyositis(DM) is an idiopathic disorder characterised by an inflammatory myopathy and characteristic skin manifestations. The average age at diagnosis is 40, and almost twice as many women are affected as men. In 1975, Bohan and Peter first suggested a set of criteria to aid in diagnosing and classifying DM and polymyositis. The cutaneous manifestations consist of heliotrope(red-purple edematous erythema on the upper palpebra), Gottron's sign( red-purple keratotic, atrophic erythema or macules on the extensor surface of finger joints), slightly raised red-purple erythema over elbows or knees. Proximal muscle weakness which is usually associated with muscle tenderness and changes on electromyography (short-duration, polyphasic motor unit potentials with spontaneous fibrillation potentials), may precede or follow the cutaneous manifestations. Systemic manifestations inculding arthralgias, arthritis, dyspnea, dysphagia, arrhythmias, and dysphonia may occur in DM but malignancy is common in adults over the age of 60 years. Serum creatine kinase and aldolase levels are usually raised. Although a positive antinuclear antibody result is common in patients with DM but anti-Mi-1 is highly specific for DM. The cutaneous manifestations are treated by avoiding sun exposure and by using sunscreens, topical corticosteroids, antimalarial agents, and/or methotrexate. The myopathy component is treated with oral corticosteroids with or without an immunosuppressive agent.
1. Bohan A, Peter JB: Polymyositis and dermatomyositis (first of
two parts). N Engl J Med 1975 Feb 13; 292(7): 344-7
2. Callen JP: Dermatomyositis. Lancet 2000 Jan 1; 355(9197)
3. Euwer RL, Sontheimer RD. Dermatologic aspects of myositis. Curr
Opin Rheumatol 1994;6:583-9.
symmetric erythematous scaly patches and periorbital edema