The article describes our own observation of two patients with juvenile dermatomyositis, 2-year-old girl and 11-year-old boy. The modern classification of the disease, clinical signs, and fundamentals of differential diagnosis are described based on the literature data, in particular, we specified the differences between the juvenile and adult dermatomyositis, analyzed adequate strategies of the diagnosis, therapy, and prevention. Case reports described in this article should draw attention of dermatologists to characteristic features of clinical presentation, diagnosis, differential diagnosis, and treatment of this disease.