This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Unknown
Isomorphism not seen in: 
Select and explain. 
A. Lichen planus, B. Warts, C. Psoriasis, D. Vitiligo
D: Vitiligo
Answer: D: Vitiligo 
Explanation: Isomorphism or Koebner phenomenon-It means linear lesions produced by scratching a primary lesion which results in new lesions developing along the line of the scratch. Eg: Lichen planus, warts and psoriasis. But Koebner phenomenon is characteristic for Lichenplanus.