TY - CHAP M1 - Book, Section TI - Photochemotherapy and Photodynamic Therapy A1 - Hönigsmann, Herbert A1 - Szeimies, Rolf-Markus A1 - Knobler, Robert A2 - Kang, Sewon A2 - Amagai, Masayuki A2 - Bruckner, Anna L. A2 - Enk, Alexander H. A2 - Margolis, David J. A2 - McMichael, Amy J. A2 - Orringer, Jeffrey S. Y1 - 2019 N1 - T2 - Fitzpatrick's Dermatology, 9e AB - AT-A-GLANCEPhotochemotherapy (psoralen and ultraviolet A light [PUVA]) has been successfully used for more than 40 years. Its effectiveness has profoundly influenced dermatologic therapy in general, providing treatment for many diverse disorders besides psoriasis and vitiligo.PUVA can be combined with topical treatments and with some systemic agents (retinoids, methotrexate, and, perhaps, biologics) to enhance efficacy and to reduce the number of exposures.The most important adverse effects of oral PUVA consist of an increased risk of squamous cell carcinoma and a possible risk of melanoma. No such increased risk was found so far with bath-PUVA.Extracorporeal photochemotherapy (ECP) was introduced in the 1980s for the palliative treatment of erythrodermic cutaneous T-cell lymphoma.ECP appears to have a major impact in the treatment of graft-versus-host disease after allogeneic bone marrow transplantation where it allows progressive reduction or even discontinuation of the concomitant immunosuppressive therapy without an increase in graft-versus-host disease activity. Several other indications are under investigation.No serious side effects have been reported with ECP.Photodynamic therapy (PDT) for skin tumors started with the introduction of topical photosensitization by a porphyrin precursor (5-aminolevulinic acid or its methyl ester) that would avoid generalized light sensitivity over many weeks.Current experience with PDT of epithelial cancers and precancerous conditions suggests that actinic keratoses, Bowen disease, superficial and nodular basal cell carcinomas, and early squamous cell carcinomas can be treated curatively.Cosmetic outcomes following PDT are excellent; therefore, it is also used for rejuvenation purposes, frequently in combination with laser treatment.The only significant side effect of topical PDT is a stinging pain during and shortly after irradiation. With daylight-mediated PDT, pain is no longer an issue. PDT has neither mutagenic nor carcinogenic potential. SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/04/19 UR - accessmedicine.mhmedical.com/content.aspx?aid=1161346310 ER -