Koebner response

Psoriatic lesions may develop at the site of injury on normalappearing skin (Koebner response). This response may be induced by a variety of trauma that includes rubbing, venipuncture, bites, surgery, and mechanical pressure. The mechanism for a Koebner response is unknown, is not unique to psoriasis, and yet occurs in a majority of psoriatic patients. Duration of time between injury and lesion development may vary from a day to several weeks. 

The association between trauma and psoriasis was first described by Heinrich Koebner in the i8th century. The Koebner response refers to the development of an overt lesion of psoriasis following an injury to previously normal appearing skin. This new lesion of psoriasis has morphology identical to the injury thus, it is also known as an isomorphic response . Koebner phenomenon tends to occur more commonly in patients with active psoriatic disease (Eyre and Krueger 1991). 

In an epidemiological study of 1253 psoriatic patients, Melski et al. (1983) found that one-third of the study population had a history of Koebner response at sites of physical trauma. These patients were also found to be associated with earlier onset of psoriasis in life and a tendency to flare despite various treatment options. Apart from the limitations of this study, the authors believed that there is indeed a subset of psoriatic patients, in which Koebner phenomenon may be an important marker. Thus, it is important to identify psoriatic patients and discourage them from engaging in jobs in which they will be subject to excessive trauma. 

Ancona A, Fernandez-Diez J, Bellamy C (1986) Occupational induced psoriasis. Dermatosen 34 71-73 Eyre RW, Krueger GG (1991) The Koebner response in psoriasis. In Roegnik HH Jr, Maibach HI (eds) Psoriasis. Marcel Dekker, New York, pp 135-147... 

Fisher AA (1979) Occupational palmar psoriasis due to safety prescription caps. Contact Dermatitis 5 56 Kanerva L, Talvi A, Estlander T (1998) Occupational contact psoriasis. Eur J Dermatol 8 217-218 Melski JW, Bernhard JD, Stern RS (1983) The Koebner (isomorphic) response in psoriasis. Arch Dermatol 119 655-659 Moroni P, Cazzaniga R, Pierini F, Panella V, Zerboni R (1988) Occupational contact psoriasis. Dermatosen 36 163-164 Rietschel RL, Fowler JF (1995) Fisher s contact dermatitis, 4th edn. Williams and Wilkins, Baltimore, pp 92-113... 

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