Pruritus and hydration state of stratum corneum in hemodialysis patients

Xerosis is the most frequent cutaneous manifestation in hemodialysis (HD) patients, but the association between dry skin and pruritus remains to be clarified. Since the skin surface hygrometer can detect the changes of water content in the stratum corneum more sensitively, we re-examined the relationship between the severity of pruritus and water content in dialysis patients.

Fifty patients who had been undergoing regular HD were examined for the degree of pruritus by clinical grading. Water contents in the stratum corneum at volar forearm and lower leg were assessed by measurement of high-frequency conductance using a skin surface hygrometer both at pre- and postdialysis.

Thirty-seven (74%) of dialysis patients complained of pruritus. High-frequency conductance values were significantly lower in HD patients compared to those of age-matched control subjects (n = 13) both at forearm (35.1+/-3.0 vs. 73.3+/-10.4 microS, p<0.01) and lower leg (14.2+/-1.1 vs. 52.4+/-7.5 microS, p<0.01). There was no relationship between the severity of pruritus and age, gender, HD duration, underlying renal disease, or removing fluid volume. A significant reduction of itching score was found in patients using polysulfone membrane. A single HD session using cellulose triacetate or polysulfone membrane significantly increased water content both at forearm and lower leg (p<0.05). However, the degree of pruritus did not correlate with the skin water content both at the beginning and the end of HD session, respectively.

It follows from these findings that water content in the stratum corneum was reduced in HD patients, but did not correlate with the severity of pruritus.