Leprosy. Recognition and treatment

Abstract

Leprosy is a slowly progressive, chronic infectious disease caused by the bacillus Mycobacterium leprae. It is a very serious, multilating and stigmatizing disease in many parts of the world and early diagnosis and therapy is the most important strategy for its control. The skin and peripheral nerves are the most affected organs. It is highly infective, but has low pathogenicity and low virulence with a long incubation period. The geographical distribution of leprosy has varied greatly with time and it is now endemic only in tropical and subtropical regions such as India and Brazil. The diagnosis of leprosy is made from the clinical picture, but must be complimented by skin bacilloscopy and histopathology. Leprosy has a number of distinct clinical presentations. Indeterminate leprosy is frequently the initial form consisting of a few lesions that either evolves into the other forms or resolves spontaneously. Lepromatous leprosy is the more contagious form and affects mainly the skin. In addition, some peripheral nerves may be thickened and other symptoms maybe present. The tuberculid form affects the skin and nerves, although usually there are few lesions. There is also a form borderline between the lepromatous and tuberculoid forms. Current treatment of leprosy involves use of 3 drugs: rifampicin (rifampin); clofazimine; and dapsone. Multidrug therapy aims to effectively eliminate M. leprae in the shortest possible time to prevent resistance from occurring. The duration of therapy was recently reduced from 24 to 12 months. Other treatment options are under evaluation in both preclinical and clinical trials and a number show promise. The combination of rifampicin, ofloxacin and minocycline given as a single dose has been recommended for the treatment of paucibacillar leprosy. Only when physicians, other health workers, and the population in endemic countries become fully aware of, and able to recognize, the disease in its initial phase, will it be possible for therapy to be instituted at the very beginning with either the standard scheme or the newer ones. Intervention at such an early stage will avoid the onset of the more serious signs and symptoms, meaning that leprosy will eventually become a less important public health problem. Therefore, efforts must be made to alert populations at risk and all health workers of the importance of an early diagnosis and treatment in leprosy infection.