A brief report on the history of phototherapy.

From ancient times, light has played a significant role in the treatment of diseases. The modern discoveries (eg, ultraviolet radiation) and modern inventions (eg, the electric generator or the electric lightbulb), as well as balneologic experiences of the treatment with sunlight, contributed to the transition from heliotherapy to artificial light phototherapy at the end of the 19th century. Nils Ryberg Finsen (1860-1904) was the founder of modern phototherapy. He is famous for applying an electric carbon arc torch in treating patients with lupus vulgaris using ultraviolet radiation. Subsequently, phototherapy using artificial light sources gained importance in the treatment of skin diseases with a noninfectious etiology. William Henry Goeckerman (1884-1954) chose an ultraviolet B light to treat psoriasis. Improvement in the effectiveness of dermatologic phototherapy occurred in 1947, when methoxypsoralen was isolated. During the 20th century, phototherapy was applied to new therapeutic areas, such as neonatology, psychiatry, and ophthalmology.