Uwe Paasch

Objective: The objective of our in vitro study was to compare the extent and timing of heat shock protein 70 (HSP70) expression following non-ablative fractional laser (NAFL) Er:Glass as well as Nd:YAG and alexandrite laser systems. Background: The role of HSP70 has been established in wound healing. Reports indicate that HSP70 expression increases after skin laser interventions. Methods: Human skin ex vivo explants were subjected to different fluences and pulse durations by using the three laser systems. Assessments were conducted on days 0, 1, 3, and 5 post-laser intervention. HSP70 expression was assessed by immunohistochemistry using anti-HSP70. Results: Er:Glass interventions caused the most significant increase in HSP70 expression whereas alexandrite interventions resulted in the least HSP70 expression, although significant compared with controls. HSP70 expression rose rapidly and dissipated quickly after Er:Glass and Nd:YAG interventions. Epidermal damage was most noted after Er:Glass interventions followed by the Nd:YAG and alexandrite systems. Conclusions: Non-ablative laser systems induce the expression of HSP70. Therefore, laser treatment may be considered 1–3 days before anticipated skin trauma to minimize scar formation provided the future validation of our data in an in vivo setting. The NAFL Er:Glass has the most potential for HSP70, yet it has also the most potential for complications.

Die technische Fortentwicklung der jüngeren Vergangenheit bietet dem Dermatologen Zugriff auf neue Laser, Strahlquellen und Behandlungskonzepte. Seit langem eingeführte Wellenlängen zur Ablation sind nunmehr fraktioniert applizierend verfügbar und stehen nunmehr für eine wirksamere und effizientere Behandlung von zahlreichen Hautveränderungen zur Verfügung. Das gezielte Einbringung von Topika (laser assisted drug delivery; LADD) ist das wichtigste Beispiel. Die LADD erfordert eine spezifische Weiterbildung, um sicher und wirksam zur Therapie (prä‐)maligner nichtmelanozytärer Neoplasien der Haut wie der Feldkanzerisierung in Form der Laser‐assistierten photodynamischen Therapie angewandt werden zu können. Bisher verfügbare Daten weisen auf eine höhere Effektivität im Vergleich zu konventionell verwendeten Topika hin, wobei anhaltend über Weiterentwicklungen berichtet wird. Unter anderem wurde die Kombination mit Tageslicht oder alternativen tageslichtähnlichen Strahlquellen bekannt. Dieses Update basiert wie zitiert gekürzt und aktualisiert auf “Paasch, U. 2019. Laser‐assistierte photodynamische Therapie. p. 226–239. In G. Kautz (ed.) Energie für die Haut. Springer Nature, Springer Nature.”.

Technical advances in recent years have led to the development of new dermatologic laser systems, light sources, and treatment concepts. With the introduction of ablative fractional lasers (using common wavelengths) in the field of dermatology, it is now possible to more effectively and efficiently treat a variety of skin disorders. One important example of these advances is laser-assisted drug delivery (LADD). A type of LADD, laser-assisted photodynamic therapy has been successfully employed in the treatment of non-melanoma skin cancer including field cancerization. This treatment concept has been continually modified and today includes the use of daylight as well as artificial daylight systems. This update is based as cited, shortened and updated according to "Paasch,U. 2019. Laser-assistierte photodynamische Therapie. p. 226-239. In G.Kautz (ed.) Energie fur die Haut. Springer Nature, Springer Nature".

Introduction: Induction of collagen and elastin remodeling in the human skin can be achieved by non-ablative fractional laser (NAFXL) and ablative fractional laser (AFXL). Our objective was to compare the safety, efficacy, tolerability, and ability to induce collagen and elastin remodeling of NAFXL versus AFXL in a series of treatments over time. Materials and Methods: In this prospective, proof of principle, single-case study, the safety, tolerability and efficacy of the laser systems were assessed via histopathology and clinical evaluations including photographs. Optical biopsies by means of multiphoton tomography (MPT) were used to evaluate the induction of collagen and elastin remodeling. Results: Treatments by both NAFXL and AFXL were well tolerated. The NAFXL system was found to be less painful and resulted in a shorter down- and healing times. MPT findings showed the superior capability of the AFXL procedure to induce collagen; on the other hand, elastin induction was more pronounced after NAFXL treatments. Conclusions: While NAFXL is as effective and safe as the traditional AFXL, it is better tolerated and has a shorter downtime. Serial optical biopsies over time over time can be a useful tool to assess the induction of collagen and elastin remodeling in the human skin.

Zusammenfassung: Technische Innovationen der letzten Jahre führen zu neuen dermatologischen Lasern, Strahlquellen und Behandlungskonzepten. Bekannte Wellenlängen, die neuerdings auf der Basis von LED emittiert werden können, ermöglichen die Kombination verschiedener Gewebeeffekte und lassen bessere Ergebnisse erwarten. Laserepilationen werden infolge simultaner Applikation verschieden wirksamer Wellenlängen auf Diodenbasis effizienter. Die Gefäßbehandlung wird in naher Zukunft ebenso von neuen LED beeinflusst werden, da auch hier die Kombination von Wellenlängen Vorteile erwarten lässt. Möglicherweise lassen sich in Zukunft auch komplexe Farbstofflaser durch LED ersetzen. Zur Entfernung kleiner Pigmente wie in Tätowierungen sind nunmehr Pikosekundenlaser verfügbar.

Summary: Technical advances in recent years have led to new dermatologic laser systems, light sources, and treatment concepts. Commonly used wavelengths – generated today with LED‐based devices – allow for the combination of various tissue effects and are associated with improved outcomes. Laser hair removal has become more efficient with the use of diode lasers that emit multiple wavelengths simultaneously. In the near future, novel LED‐based lasers will also be introduced for the treatment of vascular lesions. Here, too, the combination of different wavelengths promises to be beneficial. Picosecond lasers have led to advances in the field of pigment removal (tattoos).

Lasers provide sound help in daily dermatology, despite the fact that those systems may be almost always substituted by other methods. On top of that lasers are dangerous, expensive, difficult to use and do require manual skills. Therefore additional efforts are required to qualify for laser treatments in order to achieve stepwise practical experience with no complications. Laser interventions in well trained hands however open the way to more precise, quick, esthetic and elegant way of treatment. The 2004 founded structured specialization in laser dermatology (Facharztgrundseminar "Laser in der Dermatologie") aimed on establishing a qualified education platform for dermatologists referenced by the certificate "Laser in der Dermatologie". Standard items of training of the courses lasting for 14 years as well as ongoing changes in laws and rules are highlighted.