Koebner phenomenon

One of the classic features of psoriasis is its tendency to Koebnerise, that is to form along the line of injury or trauma. The trauma may be an acute episode such as a surgical incision or a low-grade long-term influence like the constant rubbing of a garment. Where a linear incision is made, the psoriasis is likely to follow the line of the scar rather than forming in its usual oval shape. Patients who are undergoing non-essential surgical interventions should be warned of the possibility of Koebnerisation.