An 11-year-old girl presented with a 3-month history of myalgia ofthe upper and lower limbs, progressive severe asthenia and positiveGower’s sign. Erythema overlying the palmar surfaces of both hands(Fig. 1) had appeared in the last month without other skin signs.Blood tests showed elevated Creatine Kinase (1988 U/L), AspartateAminotransferase (112 U/L), aldolase (80 U/L) and Erythrocyte Sedi-mentation Rate (61 mm/h), with normal blood count, lactic acid andthyroid function. Echocardiography, abdominal ultrasound and eyeexamination were normal. Electromyography showed an inamma-tory pattern. Capillaroscopy showed a subversion of the capillaryarchitecture of the nail bed and microvascular alterations (Fig. 2).What is the most likely diagnosis?
