This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Autoimmune skin disorders, Subject name: Dental
A person came with a unilateral white skin lesion with leukotrichia. Diagnosis is 
Select and explain. 
A. Segmental vitiligo, B. Piebaldism, C. Albinism, D. Nevus achromicus
B: Piebaldism
Answer: B: Piebaldism 
Explanation: Piebaldism is a rare autosomal dominant trait characterized by well-demarcated hypopigmented macules The most typical and common clinical picture is a white forelock often associated with a V-shaped area of leukoderma on mid-forehead Mostly seen over the anterior poion of the limbs, seen on the face paicularly on the chinLesions can be bilateral but not always symmetrical Other features: inter-pupillary distance is increased (Ref: Rook's page 1856 chapter 70.30)