[Phototherapy in the "City of Light" Jena].

In 1801, ultraviolet (UV) radiation was first described in Jena (Germany). Over the course of the last 200 years, the city has developed into a university and industry center for glass production, optics and spectroscopy. How this development influenced dermatotherapy in Jena is the subject of this article. In the late 19th century, the developing glass and optic industry of Jena played a leading role in the production of electric lamps for therapeutic use. Although production in Jena did not become established for dermatotherapeutic lamps, Jena glassmakers remained a supplier of UV filters. The industry's fortunes were generously spent on development of the city and university and enabled the creation of a dermatology clinic in an independent building. A department of radio- and phototherapy was established and since then has been part of the dermatology clinic's therapeutic portfolio. Although the city of Jena faced heavy economic repression, the industry and the dermatology clinic's scientific activity expanded to fluorescence and protein diagnostics in the early 1960s. Investigations by Professor Heinz Langhof led to the description of erythropoietic protoporphyria (EPP) simultaneously, but independently from English colleagues, whose publication is considered EPP's first description. The first functioning laser in the former German Democratic Republic was built at the university, although the first laser beam was created by a research group in Berlin a short time before. Use of laser technology in the dermatology department proceeded only after political changes began. Despite economic hardships, excellent research was done in Jena through intense collaborations. The dermatology clinic has thus been able to offer modern phototherapy from the very beginning.