LEPROSY REACTIONS - CURRENT AND FUTURE APPROACHES TO MANAGEMENT

Leprosy reactions are a major cause of morbidity and nerve function im pairment (NFI) in leprosy patients. They are immunologically mediated episodes of acute or subacute inflammation which can occur at any stag e of therapy. Reversal reaction (RR) is caused by a spontaneous increa se in T cell reactivity to Mycobacterium leprae, resulting in increase d inflammation of skin lesions, nerve trunks and loss of motor and sen sory function. More subtle forms of progressive NFI without apparent i nflammation in the skin or nerves may be detected only by serial testi ng. Acute RR responds to the prompt introduction of immunosuppressive doses of prednisolone which must be continued for 4-6 months to permit maximal recovery and prevent relapse. Recent NFI of < 6 months durati on may also be reversed by corticosteroids. Erythema nodosum leprosum (ENL) is a systemic reaction associated with the deposition of extrava scular immune complexes and affects many organs, most notably the skin , nerves, eyes and kidneys. Mild episodes of ENL may respond to simple anti-inflammatory drugs; however, severe ENL with involvement of nerv es requires prednisolone treatment. The judicious use of thalidomide i n selected patients contributes to the control of ENL, as does clofazi mine at high doses.