There is no exact number of years of life expectancy for dermatomyositis, but it is mainly based on the severity of the patient’s condition and the effectiveness of the treatment. After early diagnosis and treatment, patients generally have a better prognosis, with a 5-year survival rate of 80.4%. If the treatment is not timely, it can cause irreversible damage and affect the patient’s prognosis, and if the disease progresses rapidly, death may occur in 1-2 years. Dermatomyositis is an autoimmune disease characterized by muscle inflammation, characteristic dermatitis, and lymphocytic infiltration. Such patients may be accompanied by irregular fever, weakness, wasting, anemia, and painful joint enlargement. Patients with dermatomyositis gradually develop skin lesions and muscle weakness, and some patients often develop multi-organ lesions, which can be accompanied by tumors. Patients are treated with symptomatic general therapy, as well as glucocorticoids and immunosuppressive drugs. The prognosis of patients is mainly affected by severe muscle weakness due to delayed treatment, irreversible myasthenia and respiratory failure. Patients with severe heart disease and malignant tumors often have a poor prognosis. The occurrence of dermatomyositis is related to the low physical fitness of the patient, so you can usually do more outdoor exercises to enhance your physical fitness and improve your resistance. Patients should go to the hospital as soon as possible after the disease to check for hidden malignancies and to avoid infections that can cause acute exacerbation of the disease. Severe patients should pay attention to bed rest, while performing joint and muscle activities to prevent muscle atrophy.