Lucio’s phenomenon is an acute inflammatory event characterized by leukocytoclastic vasculitis and endothelial proliferation, with massive presence of Mycobacterium leprae in the vascular endothelium. It is considered a rare leprosy reaction seen in diffuse lepromatous leprosy, typically in untreated or inadequately treated patients. It has high mortality, severity, and rapid progression. This case report highlights Lucio’s phenomenon as a manifestation of relapse in a previously treated patient with diffuse lepromatous disease and underscores the importance of controlling secondary infection for survival. A 56-year-old man with a history of leprosy treated in the 1990s was admitted after being found in poor hygienic conditions, with two weeks of fever associated with skin necrosis of the face, upper and lower limbs, buttocks, and scrotum. In addition to extensive purpuric macules and necrotic crusts, he had purulent drainage with underlying collections in fingers and toes, fever, weight loss, and elevated infectious/inflammatory markers. Material collected from the edge of an ulcerated lesion confirmed histopathologically skin infarction with vasculitis and leukocytoclasia, with a high bacillary index (5+), compatible with Lucio’s phenomenon. He received targeted antimicrobial therapy for leprosy and secondary infection, anticoagulation with enoxaparin, arterial vasodilation with pentoxifylline, and high-dose corticosteroids. He progressed to hospital discharge criteria and transitioned from intravenous to oral therapy. The patient had multiple untreated cutaneous infectious foci. Beyond immunologic management of Lucio’s phenomenon and relapse treatment, this case illustrates the essential role of controlling the aggravating factor—secondary cutaneous infection. Recognizing the reaction and secondary infection and promptly initiating appropriate therapy were crucial to reduce mortality associated with one of the most frequent complications: sepsis.
Lima et al. (Sun,) studied this question.