Juvenile dermatomyositis (JDM) is a rare systemic disease of unknown etiology characterized by inflammation of the muscle, skin and digestive tract, with variable outcome. The diagnostic criteria include proximal symmetrical muscular weakness, characteristic skin rashes, elevation of skeletal muscle enzymes and specific electromyographic and muscle biopsy abnormalities. Pulmonary and gastro-intestinal involvements, calcinosis and generalized edema usually indicate severe disease. Recent data suggest an association between the genotype -308 AA of the Tumour Necrosis Factor (TNF) gene and disease chronicity. We present a case of a 14 year-old female with JDM and generalized oedema which is a rare manifestation of the disease and it is associated to a poor outcome.