Atmospheric pressure plasma in dermatology: Ulcus treatment and much more

Plasma in the sense of ionized gas can be referred to as the fourth state of matter following solids, liquids, and gases in view of their energy content. Application of high voltages across small gas filled spaces results in ionization of the air. Generally, two types of cold plasma can be discerned: direct plasma (e.g. dielectric barrier discharge-DBD) and indirect plasma (plasma torch, plasma jet). In indirect plasma treatment, the plasma is produced in a remote cavity and ejected by gas flow onto the skin in the form of an effluent. In direct plasma treatment, the skin itself acts as the counter electrode. Advantageous features of direct plasma treatment include the higher plasma density as well as the induced high frequency electric current onto the skin. In plasma treatment antiinflammatory, antipruritic, antimicrobial, tissue stimulation, stimulation of microcirculation, and other therapeutic effects are achieved in a single treatment due to the combined action of ultraviolet radiation, reactive oxygen species (e.g. ozone), reactive nitrogen species, and electric fields. In line with other reports, we have already demonstrated the use of direct plasma treatment in skin disinfection, in atopic eczema (superinfected dermatitis), in modulating the epidermal barrier, as well as in chronic wound treatment. We as well as others did not notice any side effects of plasma treatment so far. In summary, cold atmospheric pressure plasma constitutes a new and innovative treatment option especially for superinfected skin diseases. These promising relatively new clinical applications warrant further carefully conducted translational research to delineate the modes of actions of plasma as well as potential long term side effects. This should lead to norms for the technical devices to allow a standardized treatment of given diseases in the mid-term.