<prompt> Large unilateral hypopigmented lesion on right trunk and arm in female. Which of the following best explain the etiology for it?Autoimmune hypothesisNeurogenic hypothesisGenetic factorsSelf destruct theory of Lerner  <response>: Image shows large UL hypopigmented lesion on right trunk and arm in young female: segmental vitiligo. Vitiligo Segmental Non segmental Unilateral along dermatome Localised Generalised Focal: few mucosal: mucosa -Vulgaris - MC, BL symptoms - Acrofacial including hand and face - Universalis 90 Etio: Autoimmune condition - Antibody formed destroy melanocytes Neurogenic hypothesis - It is only valid for segmental type The image shown above in question is of Segmental vitiligo Self-destruct theory of Lerner - Given for vitiligo It states that the oxidative stress which is going on in body causes destruction of melanocytes. If question would be about Vitiligo or BL type, answer would be Autoimmune hypothesis. If there is family history of Vitiligo , answer would be Genetic factors 