Iatrogenic Calcinosis Cutis Successfully Treated with Topical Sodium Thiosulfate.

Calcinosis cutis is a term used to describe a group of disorders in which calcium salt deposits form in the skin and subcutaneous tissue. We report a 6-year-old boy with hypoparathyroidism after thyroidectomy who was admitted to the hospital for severe hypocalcemia being treated with calcium gluconate intravenous infusion through peripheral veins. Within a few days we made a diagnosis of iatrogenic calcinosis cutis and treatment with 10% topical sodium thiosulfate was prescribed; complete resolution of lesions was achieved after 6 months, with no local or systemic adverse effects. Because of the lack of noninvasive alternatives and the good tolerance of the treatment, especially in childhood, we suggest the topical use of this drug as an option for this condition.