Photodynamic therapy in dermatology

Application of non-ionising radiation with or without photosensitizers is rather common in dermatology. Though the method itself was described in ancient times, its routine use in medicine based on scientific research started in the second half of the 20th century. Light can be used in three different patterns: phototherapy (UV-A or UV-B light), photochemotherapy (combination of psoralens with UV-A light) and photodynamic therapy (combination of photosensitizers with UV- and/or visible light). The following article deals with the photodynamic therapy or PDT. Using PDT implies the understanding of light dosimetry and calculation of light dose using different light sources and photosensitizers. The number of PDT sensitisers under investigation is rapidly increasing. The PDT itself, being a relatively new modality, quickly spreads its list of applications covering new indications in different areas of medicine. Though the main part of this list is made up of dermatological conditions, the use of PDT in other disciplines is also discussed to make dermatologists familiar with different aspects of the issue. PDT, like any treatment modality, has its benefits and adverse effects. The future of PDT is closely related to teamwork in physical, biochemical and clinical research which could provide better understanding of underlying mechanisms and help to create protocols for higher therapeutic efficacy.