Elisabeth Kohl

Skin ageing: Skin ageing

Similar to the entire organism, skin is subject to an unpreventable intrinsic ageing process. Additionally, skin ageing is also influenced by exogenous factors. Ultraviolet radiation in particular results in premature skin ageing, also referred to as extrinsic skin ageing or photoageing, which is the main cause of the changes associated with the ageing process in sun‐exposed areas. Despite their morphological and pathophysiological differences, intrinsic and extrinsic ageing share several molecular similarities. The formation of reactive oxygen species and the induction of matrix metalloproteinases reflect the central aspects of skin ageing. Accumulation of fragmented collagen fibrils prevents neocollagenesis and accounts for the further degradation of the extracellular matrix by means of positive feedback regulation. The importance of extrinsic factors in skin ageing and the detection of its mechanisms have furthered the development of various therapeutic and preventive strategies.

Clinical, histopathological and immunohistochemical assessment of human skin field cancerization before and after photodynamic therapy

Summary Background  The field cancerization concept in photodamaged patients suggests that the entire sun‐exposed surface of the skin has an increased risk for the development of (pre)‐malignant lesions, mainly epithelial tumours. Topical photodynamic therapy (PDT) is a noninvasive therapeutic method for multiple actinic keratosis (AK) with excellent outcome.

In vitro and in vivo comparison of two different light sources for topical photodynamic therapy.

Background  Photodynamic therapy (PDT) with 5‐aminolaevulinic acid (ALA) is an effective and safe treatment option for the treatment of actinic keratosis (AK). Incoherent lamps are often used, matching the absorption maxima of ALA.

Photodynamic therapy for skin rejuvenation: treatment options – results of a consensus conference of an expert group for aesthetic photodynamic therapy

In addition to providing effective treatment for non‐melanoma skin cancers or their precursors, photodynamic therapy (PDT) has also attracted considerable attention for its use on aesthetic dermatology. In a first consensus publication the mechanisms of action of its photorejuvenation effects and recent studies were presented; in this paper treatment protocols for the different anatomical regions exposed to chronic sun damage like face, neck, décolleté and the back of the hands are given and suitable procedures for pre‐ and after‐care are discussed.

Aesthetic effects of topical photodynamic therapy.

Topical photodynamic therapy has shown to be effective for the treatment of several aspects of skin ageing. Multiple studies have demonstrated improvement of fine wrinkles, mottled hyperpigmentation, tactile roughness and sallowness. These results are supported by immunohistochemical analysis that revealed both upregulation of collagen production and increased epidermal proliferation. Neocollagenesis as an indirect dermal effect of photodynamic therapy is stimulated through cytokine induction. This article reviews the available literature for photodynamic rejuvenation while discussing cosmetic effects, light sources, adverse effects and the mechanism of action.

Quality of life in health care of non-melanoma skin cancer - results of a pilot study.

Background: Modern patient‐oriented medicine increasingly involves psychosocial aspects of disease processes in therapy evaluations. We conducted a pilot study on the implementation of a suitable device assessing the quality of life of patients with non‐melanoma skin cancer (NMSC) in clinical routine.

Photodynamic therapy for skin rejuvenation: review and summary of the literature – results of a consensus conference of an expert group for aesthetic photodynamic therapy

Skin rejuvenating effects of photodynamic therapy (PDT) for photoaged skin has been well‐documented in several clinical trials. Different photosensitizers (5‐aminolevulinic acid, methyl aminolevulinate) and diverse light sources (light‐emitting diodes, lasers, intense pulsed light) have been used with promising results. An improvement of lentigines, skin roughness, fine lines and sallow complexion has been achieved with PDT. These clinically evident effects are at least in part due to histologically proven increase of collagen and decrease of elastotic material in the dermis. Effective improvement of photoaged skin, simultaneous treatment and possibly also prevention of actinic keratoses, the possibility of repeated treatments and, in contrast to other procedures, limited and calculable side effects make PDT a promising procedure for skin rejuvenation.

Photodynamic therapy in dermatology

Photodynamic therapy (PDT) is a modern therapy modality, based upon the application of a photosensitizing agent like aminolevulinic acid, a physiological precursor of porphyrins, onto the tissue followed by illumination with light of the visible wavelength spectrum. During this oxygen‐dependent reaction, reactive oxygen species (ROS) are generated that have immunomodulatory or cytotoxic effects. PDT shows excellent cosmetic results especially for its key indication in dermatology – the treatment of non‐melanoma skin cancer. The associated pain and the low tissue penetration are the most frequent limiting factors of PDT. We review basic principles and recent developments in photosensitizers and light sources. Key oncological and non‐oncological indications are presented as well.

Indocyanine green‐augmented diode laser therapy of telangiectatic leg veins: A randomized controlled proof‐of‐concept trial

Telangiectatic leg veins, which affect about 40–50% of adults, represent a frequent cosmetic rather than a medical problem. Besides sclerotherapy, various laser devices are common treatment options. However, complete clearance rates can only be achieved in a small number of patients.

Die photodynamische Therapie in der Dermatologie

Zusammenfassung Die photodynamische Therapie ist eine relativ moderne Behandlungsform, der die Applikation photosensibilisierender Agenzien wie 5-Aminolävulinsäure, einer natürlichen Porphyrinvorstufe, auf zu behandelndes Gewebe mit anschließender Bestrahlung mit Licht aus dem sichtbaren Wellenlängenbereich zugrunde liegt. Aus einer sauerstoffabhängigen Reaktion entstehen Sauerstoffradikale, die immunmodulatorische oder zytotoxische Effekte vermitteln. Dabei werden gerade im Haupteinsatzgebiet der Dermatologie – der Behandlung nicht-melanozytärer Hauttumoren – exzellente kosmetische Ergebnisse erzielt, wobei die mitunter hohe Schmerzhaftigkeit und geringe Tiefenwirkung die bedeutendsten Einschränkungen in der Anwendung darstellen. Basierend auf dem aktuellen Kenntnisstand werden Grundlagen und neue Entwicklungen hinsichtlich der Erforschung von Photosensibilisator-Zubereitungen und Lichtquellen sowie die Indikationsgebiete auf onkologischer wie nicht-onkologischer Basis vorgestellt.