Case 104: Calcinosis in Juvenile Dermatomyositis

Abstract

A 30-year-old woman presented with diffuse hard nodules of 10 years duration over her entire body (Fig 1) and dysphagia of 3 months duration. A physical examination revealed violaceous discoloration of the eyelids, grade 4 strength (ability to sustain movement against mild resistance) in proximal muscles, and diffuse numerous hard nodules in skin, subcutaneous, and muscular planes. She had experienced proximal muscle weakness since 6 years of age and had been taking prednisolone since then. She had no history of Raynaud phenomenon, skin thickening, or malar rash and no family history of muscle weakness or cutaneous nodules. Laboratory studies revealed a creatine phosphokinase level of 583 U/L (normal range, 60-170 U/L), a serum aspartate aminotransferase level of 93 U/L (normal range, 0-35 U/L), an aldolase level of 23 U/L (normal range, 0-6 U/L), a serum calcium level of 9.4 mg/dL (2.35 mmol/L) (normal range, 8.0-10.4 mg/dL [2.0-2.6 mmol/L]), a phosphorus level of 4.2 mg/dL (1.4 mmol/L) (normal range, 2.5-4.5 mg/dL [0.8-1.5 mmol/Lj), an albumin level of 3.8 g/dL (normal range, 3.8-5.5 g/dL), and an alkaline phosphatase level of 208 U/mL (normal range, 60-306 U/mL). Parathyroid hormone and vitamin D levels were within normal limits, and the results of urine and renal function tests were normal. Abdominal ultrasonography did not reveal nephrocalcinosis. Electromyography revealed increased insertional activity, short duration of the action potential, and polyphasic potentials with low amplitude in the quadriceps and deltoid muscles. Results of an antinuclear antibody test were negative. Radiography and skeletal scintigraphy were performed at presentation.