An update on juvenile dermatomyositis.

Juvenile dermatomyositis (JDM) is a rare, severe, autoimmune disease characterized by a small-vessel vasculopathy that primarily affects skin and muscle, but also lung, joints, gut and heart. Nowadays prompt recognition of this entity and aggressive treatment, when needed, improves outcomes and has decreased mortality that, before corticosteroid became a mainstay in therapy, could reach 40%.