<prompt> Lucio reaction is seen in -TBLeprosySyphillisLGV  <response>: Ans is b i.e., Leprosy Lucio reactionphenomenono Seen in untreated cases of lepromatous leprosy LL.o Patients develop recurrent crops of large, sharply marginated, ulcerative lesions, particularly on lower extremities,o It is due to heavy parasitism of endothelial cells, endothelial proliferation and thrombus formation which leads to ischemic necrosis. 