[Heinrich Köbner and the "isomorphic phenomenon". History and review of the literature].

The isomorphic phenomenon belongs to the probably most well-known entities of dermatology and is closely connected to the man who was the first to describe it. Today the Koebner phenomenon is well documented in a number of skin diseases and still of considerable interest. Heinrich Koebner first reported his observation in 1872 and caused considerable diverse discussion about the origin of psoriasis in the following years. Heinrich Koebner is not only well known as "father" of the Koebner phenomenon, but also as a founder of the university dermatology clinic and pioneer of dermatology in Breslau. We not only describe the life of Heinrich Koebner, but also discuss the evolution of the term "Koebner phenomenon" and its current status.