The severity of necrotizing myositis cannot be generalized. Those caused by infections are generally not serious, while those that are idiopathic and related to immune and other factors are generally more serious, and treatment only improves the symptoms, with most patients requiring lifelong maintenance therapy. Necrotizing myositis is a disease characterized by chronic inflammation of the transverse muscle and skin, which may be related to immune abnormality, heredity, infection and other factors. Generally, the symptoms of those caused by infections can be eliminated after treatment in most patients, but those caused by immune, heredity and other factors are more serious and require lifelong maintenance treatment. Necrotizing myositis is mainly manifested as symmetrical proximal muscle weakness, myopathic face, muscle atrophy, muscle hypertrophy, myalgia, myotonia and other symptoms, blood test can also be found in patients with elevated levels of serum myosin, some patients can also appear myositis-specific antibody positivity, EMG examination can be found in the contraction of the muscle wave amplitude is lower. If the diagnosis of necrotizing myositis is confirmed, it is recommended to consult a doctor in time and follow the doctor’s instructions for treatment.