Acute Necrotic Violaceous Plaques and Hemorrhagic Bullae in a 53-Year-Old Man.

A 53-year-old man from northeast Mexico presented with acute painful violaceous plaques, hemorrhagic bullae and stellate necrotic eschars on the lower limbs, dorsal hands and external ears. Examination also revealed diffuse non-nodular cutaneous infiltration, madarosis and milphosis, and generalized hypoesthesia-subtle signs of underlying diffuse lepromatous leprosy. IgG anticardiolipin antibodies were positive, raising the possibility of antiphospholipid syndrome. Skin biopsy with Fite-Faraco staining showed endothelial colonization by acid-fast bacilli and polymerase chain reaction (PCR) confirmed Mycobacterium leprae, establishing the diagnosis of Lucio's phenomenon-a rare necrotizing vasculopathy occurring in untreated diffuse lepromatous leprosy. This case illustrates how positive serological mimickers can mislead the workup away from a mycobacterial cause and underscores the need for prompt initiation of multibacillary multidrug once the diagnosis is confirmed.