Cold plasma is well-tolerated and does not disturb skin barrier or reduce skin moisture

Background: Cold plasma, a new treatment principle in dermatology based on ionic discharge delivering reactive molecular species and UV-light, exhibits strong antimicrobial efficacy in vitro and in vivo. Before implementing plasma as new medical treatment tool, its safety must be proven, as well as assessing skin tolerance and patient acceptance. Patients and Methods: We investigated the plasma effects of three different plasma sources (pulsed, non-pulsed atmospheric pressure plasma jet (APPJ) and a dielectric barrier discharge (DBD)) on the transepidermal water loss (TEWL) and skin moisture after treating the fingertips of four healthy male volunteers. Results: TEWL values were reduced by pulsed APPJ and DBD by about 20% but increased after non-pulsed APPJ by 520%. TEWL values normalized 30 min after all forms of plasma treatment. Skin moisture was increased immediately and 30 min after treatment with pulsed APPJ but was not affected by non-pulsed APPJ and DBD. Conclusions: All plasma treatments were well-tolerated and did not damage the skin barrier nor cause skin dryness. Cold plasma fulfils basic recommendations for safe use on human skin and as future option may serve as the first physical skin antiseptic.