Paul Gerson Unna
- Ducrey-Krefting bacillus
- Russell's bodies (William Russell)
- Taenzer's syndrome
- Taenzer-Unna stain
- Unna's disease
- Unna's paste
- Unna's stain
- Unna's zinc boot
- Unna-Pappenheim stain
- Unna-Politzer naevus
- Unna-Thost syndrome
Biography of Paul Gerson Unna
Paul Gerson Unna was the son of a prominent local physician, Moritz Adolph Unna (born 1813), and on his mother’s side the family had a long tradition tradition of medicine. He commenced his medical studies at Heidelberg but joined the army in the Franco-Prussian War and was badly wounded. After the war, in 1871, he returned to studies at Heidelberg, then went on to Leipzig, before he completed his medical education in Strassburg.
Unna had problems with his thesis, which contained original and contentious proposals which drew intense criticism from von Recklinghausen. As a result it was rewritten and accepted in 1875, despite continued opposition from Friedrich Daniel von Recklinghausen (1833-1910). The thesis was on the histology and developmental history of the human epidermis. (Archiv für mikroskopische Anatomie, 1876, 12: 665). This dissertation made him a name and was the harbinger of his continual unconventional and original approaches. He then received further education at Vienna under the dermatologists Ferdinand von Hebra (1816-1880), Moriz Kaposi (1837-1902, and Heinrich Auspitz (1835-1886), before returning to Hamburg where he initially joined his father's private practice in general medicine, and worked at the St. Georg hospital.
Unna soon was able to concentrate on his particular field of interest, diseases of the skin. Already in 1881 he established a private skin clinic in Hamburg. This occasioned him to abandon general practice, and in 1884 he built a new institution in the Hamburg suburb Eimsbüttel. This institution soon attracted large numbers of student from Germany and abroad. He became titular professor in 1907 and in 1908 received a position as physician-in-chief at the Eppendorf Krankenhaus.
Unna described several skin diseases, he developed several new therapies, and in 1886 introduced ichtyol and resorcin in the treatment of skin disease. Unna conducted research on the biochemical processes of the skin, and discovered the Stratum granulosum in the skin. In 1894 he introduced slide projection as a method of skin examinations.
His classical book on histopathology from 1884 established him as one of the foremost dermatologists in the world. He described the plasma cell, and conducted extensive research hunting the agent causing soft chancre, work he continued after the agent had been found by Agosto Ducrey. It was in 1927 he described the disease that bears his name. He also devised several stains used for demonstrating fungus in smear preparations.
Harshly described as a pompous little man who seldom smiled, Unna had as many admirers as detractors, but his ability and standing cannot be doubted - since he held his own with German academics who would have been rated as possibly the most competitive of all time. He himself held no academic post until he in 1919, aged 68, was appointed the first professor – ordinary honorary professor – of dermatology at the University of Hamburg.