Juvenile Dermatomyositis.

Juvenile dermatomyositis (JDM) is a systemic capillary vasculopathy. Patients present with proximal muscle weakness, raised muscle enzymes, and pathognomic skin rashes such as heliotrope rash, Gottron's papules. Main complications are calcinosis, lipodystrophy, osteoporosis. Complement-mediated damage of vessels is a major mechanism. Magnetic resonance imaging is currently widely used to diagnosis of JDM. The goals of treatment are to control inflammatory myositis and prevent disease complication. Early, aggressive treatment of JDM associated with a better prognosis. High-dose corticosteroids in combination with methotrexate is the mainstay of treatment. The course of JDM is variable.