Dermatomyositis is a non-purulent inflammatory lesion involving mainly the transverse muscles with a lymphocytic infiltrate and may or may not be associated with a variety of skin lesions. It is characterized by symmetrical weakness of the limb girdle, cervical and pharyngeal muscles, often involving multiple organs, and may be associated with tumors and other connective tissue diseases. What are the clinical manifestations of dermatomyositis? 1. Damage: Zinnia-colored edematous patches centered on the upper eyelids are the characteristic skin lesions of dermatomyositis, as are symmetrically scattered flattened purplish-red scaly papules on the sides of the fingers, elbows, and knees. 2, muscle symptoms: any part of the transverse muscle can be involved, generally more symmetrical, the proximal muscles of the limbs are involved first, and then other muscles, the most commonly invaded muscle groups are the scapular girdle muscle, the proximal muscle groups of the limbs, the neck muscle groups and respiratory muscle and heart muscle involvement, respiratory distress, palpitations, arrhythmias, and even heart failure, etc., the acute phase due to muscle inflammation, degeneration and muscle weakness, swelling, involvement of In children, dermatomyositis can cause calcium deposits in the skin, subcutaneous tissues, and the diseased muscles near the joints. 3, other symptoms: may have irregular fever, wasting, anemia, interstitial pneumonia, splenomegaly, arthritis, etc., joint swelling can be similar to rheumatoid arthritis, kidney damage is rare, about 29% of adult patients with complications of malignant tumors.