Koebner phenomenon in a patient with psoriasis Koebner phenomenon in a patient with psoriasis. Erythematous, scaly papules developed in a linear array after scratching. Typical psoriasiform papules and plaques are also seen in this patient. Source: Dermatologic Findings in Systemic Disease, Principles and Practice of Hospital Medicine, 2e Citation: McKean SC, Ross JJ, Dressler DD, Scheurer DB. Principles and Practice of Hospital Medicine, 2e; 2017 Available at: https://accessmedicine.mhmedical.com/DownloadImage.aspx?image=/data/books/1872/mckeanhm2_ch149_f008.png&sec=146981208&BookID=1872&ChapterSecID=146981177&imagename= Accessed: March 02, 2018 Copyright © 2018 McGraw-Hill Education. All rights reserved