Paul Gerson Unna

Paul Gerson Unna (1850 to 1929) was a German physician from Hamburg who specialised in dermatology and is counted among the pioneers of dermatopathology. Born to a Jewish family of physicians, he studied at Heidelberg, interrupted his studies to serve in the Franco-Prussian War where he was severely wounded, and took his doctorate at Strasbourg in 1876 with work on the histology and development of the epidermis. After training in Vienna he opened a skin practice in Hamburg in 1881 and later the Dermatologikum private hospital. His 1884 book Histopathologie der Hautkrankheiten made him one of the most prominent dermatologists of his time. He proposed ichthyol and resorcinol against skin disease in 1886, coined the term acanthosis nigricans in 1889, described the stratum granulosum, and in 1919 received the first chair of dermatology at the University of Hamburg. Unna boot, Unna disease and Unna-Thost syndrome are named for him.