VASCULAR TRAUMA AND THE PATHOGENESIS OF THE KOEBNER REACTION IN PSORIASIS

[摘要] Uninvolved skin of 20 patients with psoriasis was injured in 3 ways: (1) suction until confluent petechiae formed; (2) scarification with production of superficial bleeding; and (3) removal of layers of stratum corneum with cellophane tape to about the level of the stratum granulosum or upper stratum Malpighi, with appearance of a moist surface. The Koebner reaction failed to occur in sites of petechiae in all cases. However, 7 patients showed positive reactions after scarification, and 8 after stripping with cellophane tape. Severe trauma to superficial vessels alone is inadequate to provoke the Koebner reaction. Removal of epidermal cells to about the level of the stratum granulosum or upper stratum Malpighi is adequate to provoke the Koebner reaction in psoriasis. It could not be determined that epidermal trauma is essential in causing the Koebner reaction, because such trauma was always followed by vascular reactions.