BLOCH, IWAN (1872–1922), German dermatologist and medical historian. After graduating from Wuerzburg University in 1896, Bloch settled in Berlin as a practicing dermatologist. He was one of the first to engage in the scientific study of sex and a leader in the movement for sexual reform. His scientific publications include Die Praxis der Hautkrankheiten ("The Practice of Skin Diseases," 1908) and Ursprung der Syphilis ("Origin of Syphilis," 1911). In the latter he suggests that the disease was introduced to Europe through the Spaniards after the discovery of South America. Bloch made important contributions to the history of medicine which were published in the monumental History of Medicine of Max Neuburger. He also wrote on the history of dermatology and of Indian and Byzantine medicine. Many of his works were written under the pseudonyms of "von Welsenburg" and "Eugen Dühren."
S.R. Kagan, Jewish Medicine (1952), 427.