Background: Juvenile dermatomyositis is potentially life threatening rare autoimmune illness that mainly affects muscle and skin. Cutaneous features are useful in establishing the diagnosis of this disease.
Case summary: We report an 8-year-old male juvenile dermatomyositis who presented epidermal nevus like-lesions on the back of the right thigh. Characteristic cutaneous changes such as Gottron's papules of the hand, heliotrope rash of the eyelids, and poikiloderma-like lesions on the back were observed. Diagnosis of juvenile dermatomyositis was made by positive muscle biopsy and magnetic resonance imaging findings and typical cutaneous manifestations. However, epidermal nevus-like skin lesions, an acquired inflammatory dermatosis that follows Blaschko lines, seen in this case have been rarely reported in the literatures.
Discussion: We would like to report this case and discuss about the significance and pathogenesis of this rare cutaneous manifestation like Blaschkitis in juvenile dermatomyositis.