JADASSOHN, JOSEF (1863–1936), German dermatologist. Jadassohn, who was born at Liegnitz, studied at Breslau and was professor and director of the dermatological clinic at the University of Berne, Switzerland, from 1896. From 1917 until his retirement in 1931 he was professor of dermatology at the University of Breslau and became famous for his work on skin and venereal diseases. Jadassohn devoted much of his time to research. Maculopapular erythematosa, a scaling skin affection, is known as "Jadassohn's disease" because he first identified it and his name is also associated with the Jadassohn-Bloch skin test for allergic conditions. He described the patch test and nevus sebaceus (1895). His publications include Krankheiten der Haut und die venerischen Krankheiten written in collaboration with Albert Neisser (1900–01) and Allgemeine Aetologie, Pathologie, Diagnose und Therapie der Gonorrhoe (1910). He edited Handbuch der Haut-und Geschlechtskrankheiten (1927–32) and coedited the Archiv fuer Dermatologie und Syphilis.
S.R. Kagan, Jewish Medicine (1952), 423f.; Biographisches Lexikon der hervorragenden Aerzte (1932), 695.