Dermatomyositis is a systemic autoimmune disease that belongs to the heterogeneous group of autoimmune disorders known as idiopathic inflammatory myopathies. It is characterized by specific skin changes, proximal muscle involvement, and various systemic manifestations that vary depending on the age of onset of the disease. DM can occur in childhood, adulthood, and can be drug-induced. The cause and mechanism of the disease are not fully understood, although several factors are believed to play a role in pathogenesis, including genetic, immunological, and environmental factors. Pathognomonic skin changes of dermatomyositis include Gottron's papules, Gottron's sign, and heliotrope erythema. Other characteristic changes include Shawl's sign, V sign, Holster's sign, as well as nail and scalp changes. The most commonly affected muscles are the proximal muscles of the shoulder and pelvic girdle, while in many cases, the muscles of the neck and abdomen are affected first. Systemic manifestations of the disease include general symptoms, lung, cardiovascular, joint, and gastrointestinal involvement. In adults with dermatomyositis, an interstitial lung disease often occurs, along with an increased risk of malignancy, while in children with juvenile dermatomyositis, skin calcifications and lipodystrophy are more common. The diagnosis of the disease is based on clinical and laboratory criteria and muscle biopsy. Treatment of DM is individualized depending on the severity of skin disease, presence of muscle, and systemic symptoms. Photoprotection along with appropriate local or systemic therapy plays an important role in therapy.