The human skin is one of the biggest organs in terms of surface. As humans grow older, more and more people are affected by skin diseases. Although a skin disease may be addressed easily due to its accessibility, the complex structure and function of it often prevent side effect-free interventions.The observation that a fractionated treatment of the skin leads to improved results as compared with that which can be achieved by treating the whole affected area is not new. In vessels, it has been discovered that there is no need to address the structure in total along its way under the skin. In addition, there were superior cosmetic results when only parts of the vasculature were coagulated whereas intact structures did not diminish the results.Fractional lasers are named after their characteristic to deliver a laser light onto fractions or parts of the skin surface.
1By doing so, it came to our attention that the biggest human organ in size is able to replace itself up to 50% within only 4 to 6 weeks if the individual piece of skin taken out is less than 0.3 mm in diameter. These columns of treated skin can go as deep as the entire integument and are called microscopic treatment zones (MTZ). As fractional lasers enable us to trigger a skin remodeling in both the epidermal and the dermal compartment, they have found a wide acceptance in a rather short time. On a cellular level, the post-fractional wound healing is defined by a stereotypical sequence of processes, mainly triggered by the activation of heat shock proteins (HSPs) within the remaining keratinocytes, culminating in an active expulsion of pigmented irreparable tissue parts (microscopic epidermal necrotic debris [MEND]) 3 days later.
2Despite a wide use of fractional lasers to treat several skin conditions associated with aging and trauma, the door has just been opened in terms of using this extremely high capacity of self-renewal in the context of treating skin cancers, fibrosing skin diseases, inflammatory and granulomatous skin conditions, as well as infectious diseases. This review aims at summarizing the current status of fractional lasers in daily clinical routine as well as the underlying technology, and it provides an outlook for ways in which the as yet unused potential can be transferred to clinics.
Basic Concepts and MechanismsIn the past it has been shown that wounding in particular results in a typical sequence of healing, which is most often accompanied by inflammation. To specifically address skin remodeling in sun-damaged or aged skin for a long time, socalled skin resurfacing has been used. Lasers that have been
AbstractRecent insights to the potential of fractional skin treatments have established standard laser procedures to treat aged, sun-damaged skin and scars. On top of this, the concept has been extended to fibrosing conditions, to remove foreign bodies and to treat inflammatory skin diseases. The biggest potential, however, is foreseen with the option of a contact-free temporary opening of the epidermal barrier (TOR, German: gate)...