An unusual adverse effect of nadroparin injections: Calcinosis cutis

In 1988, Tumiati et al described the first case of calcinosis cutis related to a calcium-containing heparin. Since then, only 18 cases have been reported in the literature; they usually have an altered calcium-phosphate product, an elevated parathyroid hormone (PTH), or both. We report a 33-year-old patient who developed calcinosis cutis at sites of nadroparin injections without any disturbance of calcium-phosphate product, PTH, or vitamin D. The pathogenesis of calcinosis cutis secondary to nadroparin injections remains controversial; Proposed causes included metastatic, dystrophic, iatrogenic, or multifactorial etiologies. This is the first case of multiple nodules of calcinosis cutis without alterations of calcium-phosphate product, PTH, or vitamin D, which supports an iatrogenic mechanism. We also suggest that calcinosis cutis could be more frequent than we thought and is probably an underdiagnosed entity.