A pilot study to evaluate the potential therapeutic effect of hydrogen-water bathing on atopic dermatitis in humans

Background

Hydrogen molecules, which have excellent antioxidant and anti-inflammatory effects, are absorbed through the skin and spread hematogenously throughout the body. Hydrogen-water bathing (HWB) is expected to be effective against atopic dermatitis (AD); however, its usefulness remains controversial in humans.

Objective

This study aimed to determine whether HWB has the potential to have a therapeutic effect in a pilot study conducted on six patients with AD.

Methods

AD severity was assessed based on the itching intensity per the visual analog scales (VAS) and the transepidermal water loss (TEWL) values of the lesions, in addition to macroscopic observations.

Results

HWB for eight weeks ameliorated the severity of rashes and increased TEWL levels in the trunk/limb areas that could be completely immersed in the bathwater, resulting in ameliorations in severe itching. The specificity of its therapeutic effect was further investigated in one patient who first underwent HWB for four weeks, discontinued it for two weeks, and resumed it for another four weeks. The rashes on the trunk/limb areas visibly improved after four weeks of HWB but worsened again after it was stopped for two weeks, only to improve again after the resumption of HWB for four weeks. The VAS and TEWL values also showed changes that reflected the skin condition.

Conclusion

These results suggest that HWB may be useful in the treatment of AD. To conclude the effectiveness of HWB for AD, it needs to be supported by randomized controlled trials with larger sample sizes and longer study durations in the future.