Lucio's phenomenon: another case reported in Brazil.

Lucio's phenomenon is defined as a variant of type 2 leprosy reaction. It is a rare event, occurring in the evolution of leprosy of Lucio and other forms of lepromatous leprosy. It has an exacerbated proliferation of Hansen bacilli in its pathophysiology, which invade blood vessel walls and injure endothelial cells, causing endothelial proliferation and decreasing the vascular lumen. This fact, associated with inflammatory reactions and changes in the coagulation system causes vascular thrombosis, ischemia, infarction and tissue necrosis, leading to the histopathological characteristic of the phenomenon. We report a case of lepromatous leprosy with irregular treatment that developed Lucio's phenomenon. Treatment with multidrug therapy, antibiotics, steroids and thalidomide achieved a favorable outcome.