SULPHONES ARE DRUGS OF CHOICE FOR THE THERAPY OF ALL FORMS OF LEPROSY. DAPSONE IS BACTERICIDAL AS WELL AS BACTERIOSTATIC AGAINST MYCOBACTERIUM LEPRAE. MUCOSAL LESIONS ARE FIRST TO RESPOND : ORAL, NASAL, PHARYNGEAL, AND LARYGEALNODULES, INFITRATIONS, AND ULCERATIONS REGRESS AND DISAPPEAR, AND SECONDARY INFECTIONS SUBSIDE. INVASION OF THE PERIPHERAL NERVES PROBABLY OCCURS IN ALL CASES OF LEPROSY, BUT IT IS PROMINENT IN THE TUBERCULOID FORM OF THE DISEASE. THE INVOLVED EXTREMITY IS PAINFUL AND SWOLLEN. PATIENTS HARBOUR M.LEPRAE IN MUCOUS MEMBRANES, SKIN, AND NERVES LONG AFTER SUPERFICIAL LESIONS HAVE DISAPPEARED.