Treatment of hyperhidrosis manuum by tap water iontophoresis.

In a randomised, double-blind, controlled clinical trial of the effect of treatment with tap water iontophoresis, 11 patients with palmar hyperhidrosis were treated actively on one hand and with placebo on the other. The patients' sweat production was 100% higher (median) than measured in control subjects of the same age and sex. Prior to iontophoresis, the patient's sweat production was the same on both hands but after treatment it was reduced significantly on the treated hand (p less than 0.01) compared with the sweat production prior to treatment as well as with that of the untreated side. An 81% reduction (median) in sweating was found in 6 patients receiving maintenance treatment every second week.