Ultraviolet Phototherapy of Pruritus

It has been known for more than 2000 years that several skin diseases improve upon exposure to the sun. However, it was not until the end of the 19th century before Niels R. Finsen started to use sunlight as well as electric light for the treatment of skin tuberculosis.1 He was awarded the Nobel Prize in 1903 “in recognition of his contribution to the treatment of diseases, especially lupus vulgaris, with concentrated light radiation, whereby he has opened a new avenue for medical science.” The carbon arc lamp initially used by Finsen was later shown to emit longwave ultraviolet radiation. Another device, still successfully used in some circumscribed itchy skin diseases, was constructed by Gustav Bucky in 1929. This device produced ionizing radiation employing ultrasoft X-rays (0.07-0.4 nm), which Bucky called “grenz rays” since he believed that the biological effects of these rays resemble those of X-rays in some ways and ultraviolet rays in other ways