CALCA and retinitis pigmentosa 1: In scleroderma, there are fewer CGRP-supplying nerves, and in RP, there may be CGRP deficiency in the distal or acral skin.2,3 Cutaneous blood flow increases in these patients after CGRP infusion.3,4 A previous study5 examined the effects of systemic therapy with calcitonin in patients with scleroderma, finding a reduction of digital ulceration and improvement in pulmonary function after infusion.