Pruritus and mast cell proliferation of the skin in end stage renal failure.

We studied the relationships between dermal mast cell proliferation and pruritus or hyperparathyroidism in hemodialysis (HD). Skin biopsies were taken from 59 patients in end stage renal failure; 51 were on maintenance HD, and the other 8 were not. As a control, 34 non-renal failure pruritic patients were used. Thirty-one of the 59 end stage renal failure patients (52.5%) had pruritus. The incidences of pruritus found in patients on HD and those not on HD were 56.9% and 25%, respectively. Significantly larger numbers of dermal mast cells were found in HD patients than in the control. There was no clear relationship between dermal mast cell proliferation and serum parathyroid hormone (PTH) levels. We speculated that the cause of pruritus in the patients undergoing maintenance HD was due to an increase of dermal mast cells and a release of histamine as a result of extra-corporeal circulation.