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Summary of the study: The mechanism of tap water iontophoresis: a functional disturbance of the secretory epithelium

Despite decades of positive results with tap water iontophoresis for the treatment of hyperhidrosis, the exact mechanism is still unclear.

The aim of the study was to review the hitherto common hypothesis of a mechanical closure of the excretory ducts in the sweat glands and propose an alternative theory as to how tap water iontophoresis works.

Histomorphological, functional, and electro-physical examinations were performed to assess the condition of the sweat glands under tap water iontophoresis treatment. The current used came from a device made by HIDREX GmbH.

Results:

The histomorphological examination showed that the sweat glands do not close mechanically nor are there structural changes in the excretory ducts of the sweat glands after iontophoresis. All that was observed was their inactivity.

As part of the functional examination of the sweat glands after tap water iontophoresis had eliminated or reduced sweat levels, they were shown to be refractory to pharmacological stimuli, indicating that the effect takes place through a change in the postsynaptic region.

Skin resistance measurements were performed during the electro-physical examination. The low increase in resistance after tap water iontophoresis in contrast to the comparative study (use of aluminium chloride) also speaks against the closing of the excretory ducts of the sweat glands as a mechanism of action.

From the results of the study it can be concluded that the effect of tap water iontophoresis is not based on a mechanical blocking of the ducts, as had previously been assumed. Rather, it is believed that the TWI disrupts the way stimuli and secretion are coupled in the sweat glands.

(cf. Reinauer, S., Schauf, G. et al.: Wirkungsmechanismus der Leitungswasser-Iontophorese: Funktionelle Störung des sekretorischen Epithels. in: Z. Hautkr. 67 (7), 1992, p. 622-626)

Summary of the study: Treating hyperhidrosis using tap water iontophoresis: positive effects on healing time and freedom from recurrence in hand-foot eczema

Excessive sweating caused by hyperhidrosis of the hands and feet can severely restrict the lives of affected patients. This lends this phenomenon its own disease character. Morbid sweating is also discussed as a factor that worsens eczema of the hands and feet.

The aim of the study was to investigate the influence of eczema on treatment of hyperhidrosis with tap water iontophoresis. The study used a HIDREX pulse current device.

The study showed that tap water iontophoresis is not only effective in relieving excessive perspiration on the hands and feet, but also cuts the healing time and reduces recurrence of eczema. On average, there was a shorter healing time (20 days with iontophoresis vs. 22.3 days without iontophoresis), which might not be significant itself, but the length of the relapse-free period (24.8 weeks with iontophoresis vs. 8.35 weeks without iontophoresis) is highly significant.

This is not only due to the reduction in sweat but also to an influence on the inflammatory reactions in the eczematous skin. The capsaicin-like effects of the electrical current are suspected. The inflammation is interrupted, which has a positive effect on prolonged freedom from recurrence in hyperhidrotic hand-foot eczema.

(cf. Wollina, U., Uhlemann, C. et al.: Therapie der Hyperhidrosis mittels Leitungswasseriontophorese: Positive Effekte auf Abheilungszeit und Rezidivfreiheit bei Hand-Fuß-Ekzemen. in: Hautarzt (1998) 49, p. 109-113).

Pulsed DC iontophoresis as a new treatment option for hyperhidrosis

Tap water iontophoresis with direct current has become the treatment of choice for excessive sweating of the hands or feet due to its high success rate (98%).

Because of such side effects as discomfort and issues such as shocks that sometimes occur with direct current iontophoresis, the aim of the present study was to minimize the side effects of tap water iontophoresis, increase safety standards, and reduce the technical effort without losing therapeutic efficacy.

In the investigation, the effectiveness and side effects of a DC device made by HIDREX GmbH, a device with pulsed direct current with triangular voltage curve (experimental device, manufacturer unnamed), and a pulse current device made by HIDREX GmbH with rectangular voltage curve were compared.

Overview of the study’s results:

Normal sweating was achieved with DC treatment after an average of 10 treatments, with both pulse current forms achieving the same results after about 12 treatments. Adverse events such as pain, skin irritation, or mild electric shock due to improper use occasionally occurred during treatment with DC. The subjects reported few side effects when treated with pulse currents. Skin irritations occurred only rarely when subjects were treated with triangular pulse current and the occurrence was further minimized when treated with the rectangular pulse current of the HIDREX GmbH device. Neither pulse current devices caused electric shocks. Both DC and pulse current treatment with HIDREX devices was 100% effective in normalising the sweat levels of all subjects. The device using triangular pulse current was successful with only 80% of the subjects.

Conclusion: Due to the reduced occurrence of side effects, tap water iontophoresis with pulse current, despite its somewhat lower efficiency, is a viable alternative to DC iontophoresis. It should be considered the method of choice for treating children. In extreme cases of hyperhidrosis, the use of pulse current may not be sufficient. In these cases, treatment with DC is also recommended.

(cf. Reinauer, S., Neußer, A. et al.: Die gepulste Gleichstrom-Iontophorese als neue Behandlungsmöglichkeit der Hyperhidrosis. in: Hautarzt (1995) 46, p. 543 – 547)