Section : History & Terminology

Koebner isomorphic phenomenon: the story behind the name

  • The isomorphic phenomenon is the occurrence of the skin lesions in traumatized areas.
  • This occurs in the following dermatoses: vitiligo, psoriasis, lichen planus, lichen nitidus, pityriasis rubra pilaris, and keratosis follicularis (Darier’s disease).
  • It was described by Dr Heinrich Koebner (1838-1904) in 1876, a German dermatologist who trained in Paris and Vienna:
    • he showed it a a patient with psoriasis
    • lesions occurred 5 and 6 years after the first plaque appeared occurring on traumatized areas: excoriations from riding, a horse bite, a tattoo, lymaphenitis-induced suppuration….the bite had exerted the greatest influence.
  • Other achievements
    • he demonstrated the fungal origin of sycosis barbae by inoculating human fungi in rabbits
    • he described epidermolysis bullosa simplex

For the anecdote, he was an enthusiast and didn’t hesitate auto-inoculate fungal infections !


Dr Christophe Hsu – dermatologist. Geneva, Switzerland

Source of information:

-Crissey JT el al. Dermatology and Dermatologists (2002). Parthenon Publishing