Juvenile dermatomyositis (JDM) is a rare autoimmune inflammatory myopathy of childhood, characterized by proximal muscle weakness and distinctive cutaneous findings. The pathogenesis involves genetic predisposition, environmental triggers, and immune dysregulation, particularly via type I interferon (IFN) pathways. Understanding the complex immunological mechanisms and clinical spectrum of JDM is essential for improving diagnostic and therapeutic strategies. This narrative review synthesizes current literature and clinical data on the pathophysiology, autoantibody profiles, clinical manifestations, diagnostic tools, and treatment approaches in JDM. Treatment involves high-dose corticosteroids, methotrexate (MTX), and other immunosuppressives, with emerging interest in biologic agents targeting IFN pathways. Recent advances in immunogenetics and imaging have enhanced diagnostic precision and patient stratification. Early diagnosis and personalized, multidisciplinary treatment approaches are critical for improving prognosis and preventing long-term complications.