Subcutaneous fat calcinosis in adult-onset dermatomyositis.

1 of 2 DESCRIPTION Calcinosis is a well-documented manifestation seen in up to 40% of patients with juvenile dermatomyositis. It is an uncommon feature in adult-onset dermatomyositis. 1 We present a rare occurrence of calcinosis with unusual distribution in a 51-year-old male. 18-months after diagnosis, our patient was seen in clinic following an episode of cellulitis. His muscle weakness and skin rash had responded well to steroid and oral methotrexate therapy. Examination identifi ed a hard, irregular and extensive mass palpable across the abdomen. Laboratory studies revealed normal renal function, with creatine kinase elevated at 440 IU/l. Serum calcium, phosphate, parathyroid hormone and vitamin D were all within normal parameters. Malignancy was considered but the mass did not correspond to a specifi c abdominal organ. Due to the patient’s body weight of 170 kg ultrasound assessment was limited. An abdominal CT scan ( fi gure 1 ) identifi ed extensive calcifi cation in the subcutaneous fat overlying the anterior abdominal wall and buttocks, with normal intra-abdominal viscera. Despite this development, the patient demonstrated clinical improvement in his muscle power and skin rash. Consequentially, no change in the patient’s management was made. Calcinosis of the skin and muscle is unusual but recognised fi ndings in adult-onset dermatomyositis, which typically have a predilection for sites of trauma. 2 Other causes of ectopic calcifi cation such as hyperparathyroidism, hypervitaminosis D and nephropathy were excluded by relevant investigations. We demonstrate fascinating images illustrating the development of exclusive subcutaneous fat calcinosis, also known as calcinosis universalis 3 4 –a phenomenon that is only rarely reported in adult-onset dermatomyositis.