Reflectance confocal microscopy (RCM) is a novel noninvasive technique for "in vivo" examination of the skin. In a confocal microscope, near- infrared light from a diode laser is focused on a microscopic skin target. As this light passes between cellular structures having different refraction indexes, it is naturally reflected, and this reflected light is then captured and recomposed into a two-dimensional gray scale image by computer software. Focusing the microscope (adjusting the focal point on the z-axis) allows images to be obtained of different levels within the skin. Commercially available microscope systems of this type can create images with enough detail for use in histological analysis. The first investigations using these microscopes served to identify the appearance of the various cell populations living in the different layers of normal skin. Today, the main interest has become focused on the use of these microscopes as a diagnostic tool: a means of investigating benign and malignant tumors of melanocytes and keratinocytes, and, more importantly, the findings of this field of study can be used to develop a diagnostic algorithm which would be not only highly sensitive but specific as well. The aim of the paper is to provide an updated literature review and an in-depth critique of the state-of-the-art of RCM for skin cancer imaging with a critical discussion of the possibilities and limitations for clinical use.

Photodynamic therapy (PDT) is a two-step therapeutic technique in which the topical or systemic delivery of photosensitizing drugs is followed by irradiation with visible light. Activated photosensitizers transfer energy to molecular oxygen, generating reactive oxygen species (ROS). The subsequent oxidation of lipids, amino acids and proteins induces cell necrosis and apoptosis. In addition, ROS indirectly stimulate the transcription and release of inflammatory mediators. The photosensitizers are selective, in that they penetrate and accumulate in tumour cells or in the endothelium of newly formed vessels while generally avoiding the surrounding healthy tissue. The mechanisms of penetration through the cell membrane and the pattern of subcellular localization strongly influence the type of cellular effect. The photobiology and photoimmunology of the haematoporphyrin (Hp) derivative and its purified, lyophilized and concentrated form porfimer sodium have been investigated over the past 30 years. However, interest in PDT in dermatology was not raised until the 1990s with the availability of a simple and effective technique, the topical application of aminolaevulinic acid (ALA) and its methyl ester (methyl aminolaevulinate, MAL) followed by irradiation with broadband red light. At the same time, several new 'second-generation' synthetic sensitizers (e.g. benzoporphyrin derivatives, phthalocyanines, chlorins and porphycenes) became available. These compounds are chemically pure, highly efficient, selective and safe, while offering the advantage that the generalized skin photosensitivity they produce lasts for only a short time. They are currently under clinical evaluation but have not yet been approved for clinical use. This paper provides an overview of the chemistry of the photosensitizers, the photobiology and photoimmunology of the photodynamic reaction as well as the photophysical characteristics of the light sources available for PDT.

Patients with psoriasis may have a tendency to hyperhomocysteinaemia, which may predispose to higher cardiovascular risk. Dietary modification of this risk factor appears relevant to the global management of patients with moderate to severe psoriasis.