Therapeutic Effect of Topical Gamma-Linolenic Acid on Refractory Uremic Pruritus

Abstract

Pruritus is a bothersome symptom affecting up to 80% of dialysis patients. Lymphocyte and cytokine interaction has an important role in the pathogenesis of uremic pruritus. Gamma-linolenic acid (GLA) is associated with immune modulation of T lymphocytes and lymphokines. The aim of this study is to determine whether topical GLA can attenuate uremic pruritus. Seventeen dialysis patients with refractory uremic pruritus who passed the screening criteria entered a prospective, randomized, double-blind, placebo-controlled, crossover study. They stopped all antipruritic therapy at least 2 weeks before the study and were randomly assigned to treatment with either GLA 2.2% cream or placebo-based cream applied to the entire body after taking a bath once a day and to pruritic sites 3 times a day for 2 weeks, and then the reverse treatment after a 2-week washout period. Severity of pruritus was evaluated by using a traditional visual analogue scale (VAS) and a modified questionnaire method (pruritus score [PS]). Hemogram, aspartate and alanine aminotransferases, bilirubin, albumin, blood urea nitrogen, creatinine, calcium, phosphate, and intact parathyroid hormone were measured. Sixteen patients completed the study; 1 patient was withdrawn because of an allergic skin reaction. There were no significant differences between groups except for sex distribution. Median VAS and PS values between groups did not differ significantly at baseline. There is a greater antipruritic effect of GLA based on evaluation with both the VAS and PS. There is persistence of a residual effect into the second treatment period after GLA treatment. GLA-rich cream is better than placebo-based cream for alleviating uremic pruritus. It is a useful adjuvant in the management of refractory uremic pruritus.