一、疾病的概念皮肌炎是在皮肤和肌肉发生的非化脓性炎症的胶原病。其病理生理主要是由于免疫反应引起的血管炎。根据比较皮肤和肌肉病变 ,把皮肤症状轻者称为多发性肌炎。皮肌炎好发于 5～ 1 0岁和 45～ 65岁 ,在儿童发病称为儿童性皮肌炎 (juvenenile dermatomyositis,JDM)和 First, the concept of disease Dermatomyositis is a non-suppurative inflammation of the skin and muscle collagen disease. The pathophysiology is mainly due to the immune reaction caused by vasculitis. According to the comparison of skin and muscle lesions, the skin symptoms of mild known as polymyositis. Dermatomyositis occurs in 5 ~ 10 years old and 45 ~ 65 years old. In children, it is called juvenenile dermatomyositis (JDM) and