Heinrich Köbner (1838–1904) The<unk>  or Köbner<unk>  (, ), also called the<unk>  response or the isomorphic response, attributed to Heinrich Köbner, is the appearance of skin lesions on lines of trauma. The<unk>  may result from either a linear exposure or irritation. Conditions demonstrating linear lesions after a linear exposure to a causative agent include: molluscum contagiosum, warts and toxicodendron dermatitis (a dermatitis caused by a genus of plants including poison ivy). Warts and molluscum contagiosum lesions can be spread in linear patterns by self-scratching ("auto-inoculation"). Toxicodendron dermatitis lesions are often linear from brushing up against the plant. Causes of the<unk>  that are secondary to scratching rather than an infective or chemical cause include vitiligo, psoriasis, lichen planus, lichen nitidus, pityriasis rubra pilaris, and keratosis follicularis (Darier disease).
Koebner phenomenon
Crescent sign
Cupola sign
Amsler sign
Palla's sign
Sulcus sign
De Musset's sign
Markle sign