Uræmia and Mast-Cell Proliferation

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.

Section: Discussionsupporting

confidence: 93%

Uremic Pruritus and Skin Mast Cells

Dimković

Djukanović²,

Radmilović

et al. 1992

“…They have been shown to improve pruritus in some patients but either had no effect or aggravated symptoms in others. Histamine has been suggested to be the most important mediator of the itch sensation [20][21][22], However, the use of antihistamine often fails to offer sufficient relief. It is reasonable to speculate that other important mediator(s) may play a role in the generation of uremic pruritus.…”

Section: Discussionmentioning

confidence: 99%

Hemodialysis-Related Pruritus: A Double-Blind, Placebo-Controlled, Crossover Study of Capsaicin 0.025% Cream

Tarng¹,

Cho

Liu

et al. 1996

122

Pruritus is a significant symptom among patients receiving hemodialysis. However, its underlying mechanisms remain obscure. Substance P, a neuropeptide, has been implicated in the mediation of pain and some itch sensations. Local application of capsaicin depletes the peripheral neurons of substance P and may block the conduction of pain or pruritus. This study aims to assess the efficacy and safety of capsaicin 0.025% cream in the treatment of hemodialysis-related pruritus and to further explore the underlying pathomechanism. Nineteen hemodialysis patients with idiopathic, moderate (n = 5) to severe (n = 14) pruritus were examined in a double-blind, placebo-controlled, crossover study and 17 of them completed the study. Topical agent of capsaicin or placebo base cream was applied to localized areas of pruritus 4 times a day. The severity of pruritus and treatment-related side effects (cutaneous burning/stinging sensations, dryness, or erythema) were evaluated weekly. The results showed (1) that 14 of 17 patients reported marked relief and 5 of these 14 patients had complete remission of pruritus during capsaicin treatment (Wilcoxon signed-ranks test, 2p < 0.001); (2) capsaicin was significantly more effective than placebo (Mann-Whitney rank sum test, 2p < 0.001) and a prolonged antipruritic effect was observed 8 weeks posttreatment; (3) no serious side effects were noted during the study and (4) there were no significant changes in serum concentrations of albumin, calcium, phosphorus, alkaline phosphatase, or intact parathyroid hormone during the treatment with either capsaicin or placebo. In summary, the present study indicates indirectly that idiopathic pruritus in some patients on maintenance hemodialysis may be transmitted by substance P from the peripheral sensory neurons to the central nervous system. Topical capsaicin with the unique pharmacological effect is demonstrated to markedly improve the pruritus of these patients.

“…Patients with ESRF, especially those maintained on HD, suffer from several cutaneous manifestations [5,8,11,12,16]. Persistent pruri tus is a symptom which the patient can usually hardly tolerate, and is so intense that the use of antipruritics often fails to afford sufficient relief [6,7,13,16], Some authors pointed out that the mast cell prolifera tion in various organs might induce pruritus [8], diarrhea and constipation, and bone marrow damage from a re lease of histamine [1,2,10]. In the present series, numer ous mast cells were seen in the subepidermal pericapillary areas of the patients maintained on HD, with the numberof mast cells surpassing that in nondialysis ESRF patients or in reported cases of nonspecific dermatitis with pruritus [8], The mast cell proliferation did not necessarily coincide with the presence of pruritus in the present study.…”

Section: Discussionmentioning

confidence: 99%

Microangiopathic Changes of Subepidermal Capillaries in End-Stage Renal Failure

Ichimaru¹,

Horie

1987

Skin biopsies were taken from 63 patients with end-stage renal failure (ESRF) and 5 normal volunteers, 53 of whom were on maintenance hemodialysis (HD) and the other 10 without HD. They were examined with light and electron microscopy and subepidermal capillaries were subjected to image analysis. Thickening of the basement membrane (BM) with multilamination of the basal lamina, endothelial activation and chronic inflammatory cell infiltration with participation of mast cells were evident. The extent of these BM changes was correlated with the duration of HD, but not significantly correlated with the clinical findings indicative of arteriosclerosis. There was significant correlation between the duration of HD and mast cell proliferation or eosinophilia. We suspect that the subepidermal capillary changes represent an inflammatory reaction provoked by uremic toxins or by the repeated use of an artificial organ.