[Uremic arteriopathy and ischemic skin changes].

The syndrome of uremic arteriopathy with ischemic skin manifestations--livedo reticularis, skin infarction and ulcerative necrosis--is described in a series of 6 patients. In all patients (3 female and 3 male, age 53-73 years) the syndrome occurred after slowly progressive renal failure and in 5 cases during temporary exacerbation of chronic renal failure and after alkalinizing treatment for marked metabolic acidosis. All patients had evidence of secondary hyperparathyroidism. In 4 the Ca X P product was in excess of 4.90, but only once above the critical product of 5.60 (greater than 70 when conventional units are used). Diagnosis was based on the clinical appearance of the skin involvement and the finding of vascular calcifications (x-ray and skin biopsy). The secondary hyperparathyroidism appears to play an important role in the pathogenesis of the syndrome. An increase in plasma phosphate or Ca X P product, calciphylaxis and/or alkalinizing therapy may release the precipitation of calcium salts in the interstitium or in the vessel walls. Therapy is confined to decreasing plasma phosphate and therewith the Ca X P product by means of phosphate binders or a diet low in phosphate. The unpredictable, often rapid success of parathyroidectomy awaits further clarification.