摘要
Dermatomyositis （DM） and polymyositis （PM） are idiopathic inflammatory myopathies with unknown etiology. The incidence of both diseases is estimated at 4 to 10 cases per million people per year.1 Classical DM patients display characteristic cutaneous manifestations, proximal muscle weakness, and laboratorial evidence of myositis. Skin manifestations include the classic periorbital heliotrope,
Dermatomyositis （DM） and polymyositis （PM） are idiopathic inflammatory myopathies with unknown etiology. The incidence of both diseases is estimated at 4 to 10 cases per million people per year.1 Classical DM patients display characteristic cutaneous manifestations, proximal muscle weakness, and laboratorial evidence of myositis. Skin manifestations include the classic periorbital heliotrope,
