A case of calcinosis universalis successfully treated with low-dose warfarin

A 27-year-old male patient with calcinosis universalis resulting from dermatomyositis was successfully treated with low-dose warfarin. On his trunk and extremities, there were many subcutaneous calcified nodules, and knee flexion was difficult. After oral warfarin therapy for three years, the calcified nodules became smaller, and the knee mobility improved. His serum vitamin K level was abnormally high, decreased just after starting warfarin therapy, and then remained within the normal range. Since vitamin K has been known to play an important role in the Ca2+ binding process in bones or tissues, we suggest that this therapy is effective in reducing subcutaneous calcification through the vitamin K cycle.