New skin lesions developing at sites of skin trauma in a patient with psoriasis are characteristic of the Koebner phenomenon, which is also known as the isomorphic response. The Koebner phenomenon can occur with other dermatoses such as vitiligo or lichen planus. Histopathologic findings typically mirror those of the underlying skin condition. Although the psoriasis was well controlled in this patient, koebnerization is most strongly associated with active disease. Therefore, recognition has important implications for management, which includes both treatment of the underlying dermatosis and prevention of additional skin trauma.
Comment
New skin lesions developing at sites of skin trauma in a patient with psoriasis are characteristic of the Koebner phenomenon, which is also known as the isomorphic response. The Koebner phenomenon can occur with other dermatoses such as vitiligo or lichen planus. Histopathologic findings typically mirror those of the underlying skin condition. Although the psoriasis was well controlled in this patient, koebnerization is most strongly associated with active disease. Therefore, recognition has important implications for management, which includes both treatment of the underlying dermatosis and prevention of additional skin trauma.