Placebo-controlled evaluation of direct electrical current administration for palmoplantar hyperhidrosis

Background Direct electrical current (d.c.) administration based on tap water iontophoresis has been used as a therapeutic option for palmoplantar hyperhidrosis. The placebo effect of this technique has not been investigated adequately. Aim To investigate whether d.c. administration has a possible placebo effect in the treatment of palmoplantar hyperhidrosis. Methods As a placebo, low alternating electrical current (a.c.; 9–12 mA, 10–15 V, and 8–10 Hz) was applied to the palms of 15 patients with idiopathic palmoplantar hyperhidrosis. The placebo effect was evaluated by inspection and sweat intensity measurements performed before and after placebo application. Patients then received d.c. treatment (18–22 mA, 40–60 V) according to the same procedure as applied for placebo. The final sweat intensity measurements of the patients were performed 1 week after the last session of d.c. treatment. Sweat intensities measured before and after placebo and at the end of d.c. treatment were analyzed statistically by paired t‐test. Results The initial sweat intensity measurements of the palms, before placebo application, were 3.12 ± 0.39 g/h on the right side and 3.17 ± 0.28 g/h on the left side. The second sweat intensity measurements, 1 week after the last session of placebo, were 3.08 ± 0.46 g/h on the right side and 3.16 ± 0.21 g/h on the left side. There were no significant differences between the initial and second sets of sweat intensity measurements of the hands (P > 0.05 for both sides). The final sweat intensity measurements, 1 week after the last session of d.c. treatment, were 0.38 ± 0.06 g/h on the right side and 0.39 ± 0.07 g/h on the left side. Conclusions Statistical evaluation of sweat intensity measurements and inspections revealed that d.c. administration had no placebo effect in the treatment of palmoplantar hyperhidrosis.