01440nas a2200181   4500000000100000008004100001260001600042653001200058653003200070653002200102653000500124653003100129100001000160700001500170245006400185520099500249022001401244       2012                            d  c2012 Oct 2910aleprosy10aDiffuse lepromatous leprosy10aLucios Phenomenon10a10aMycobacterium lepromatosis1 aHan X1 aJessurun J00aSevere leprosy reactions due to mycobacterium lepromatosis.3 aABSTRACT:: Leprosy is caused by the well-known Mycobacterium leprae and the newly discovered M lepromatosis. Here, the authors describe 2 cases of leprosy with unusual clinical presentation caused by M lepromatosis. The patients, a 32-year-old man and a 50-year-old woman, both of Mexican origin, manifested high fever, lymphadenopathy and florid skin lesions in the form of erythema nodosum and Lucio's phenomenon as the first clinical presentation. Heavy infiltration of acid-fast bacilli was identified in the tissues that led to the diagnosis of lepromatous leprosy or diffuse leprosy. The patients were treated with multidrug regimen and responded appropriately. From the lymph node tissue, the authors showed the bacillus to be M lepromatosis, not M leprae as presumed previously, by differential polymerase chain reactions and analysis of gene sequences. These cases add to the growing studies on this organism, expand its endemic regions in Mexico and provide more clinical insight.  a1538-2990