Dystrophic calcinosis cutis in subacute lupus.

Dystrophic calcinosis cutis is known to be associated with various connective tissue disorders but to the best of our knowledge has never been reported in subacute cutaneous lupus erythematosus (SCLE), a distinctive cutaneous subset in the spectrum of lupus erythematosus. It occurs without calcium and phosphorus metabolic abnormalities and may be localized or generalized. We report a patient with SCLE who developed calcinosis cutis and had normal serum calcium and phosphorus levels and, interestingly, a normal concentration of blood ionized calcium. This latter, which represents the active form in the total amount of blood calcium, is a parameter only rarely assessed in patients with dystrophic calcinosis cutis. Thus, other pathogenic factors should be investigated to clarify the pathophysiology of the dystrophic type of calcification.