Uremic pruritus and skin mast cells.

The number of mast cells in the skin was evaluated in 25 patients with end-stage renal failure on different treatment modality (conservative, hemodialysis and peritoneal dialysis). According to the presence of pruritus, uremic patients were divided into two groups: group A, 13 patients with diffuse pruritus, and group B, 12 patients without pruritus. Controls were 6 age- and sex-matched healthy subjects. In comparison with patients without pruritus, patients with pruritus had mainly degranulated, diffusely spread and more numerous mast cells in the skin; significantly higher levels of plasma middle molecular weight substances, serum histamine and PTH and significantly lower serum iron levels. However, no differences were noted in observed parameters between groups on different treatment modalities. Favorable therapeutic effects in patients with pruritus were achieved either with iron supplementation in those with hypoferremia or with antihistamines, mast cell membrane stabilizers and high-permeability membranes.