Leprosy late-onset neuropathy: an uncommon presentation of leprosy.

Clinical and pathological findings in leprosy are determined by the natural host immune response to Mycobacterium leprae. We previously described cases of painful neuropathy (PN) with no concurrent cause apart from a past history of leprosy successfully treated. Four leprosy previously treated patients who developed a PN years after multidrug therapy (MDT) are reported. The mean patient age was 52.75 years (47-64). The mean time interval of the recent neuropathy from the previous MDT was 19 years (12-26). A painful multiplex neuritis or polyneuropathy were observed respectively in two cases. Electrophysiological studies disclosed a sensory axonal neuropathy in two cases. Microvasculitis with no bacilli was seen in nerve biopsy. Neuropathic symptoms were improved with prednisone. We consider these cases as being a leprosy late-onset neuropathy (LLON) form of presentation. A delayed immune reaction could explain the late appearance of LLON.