Relapses after multibacillary leprosy treatment

Leprosy relapses are mainly due to bacillary persistence and diamino-diphenyl-sulphone (DDS) monotherapy. Case histories were examined for 33 patients with lepromatous leprosy (LL), diagnosed 7-48 years before the relapse and treated only with DDS during 4 to 38 years. Twenty-eight patients received irregular non-supervised polychemotherapy (PCT) since 1983. Five patients received only DDS, and presented relapses 13-20 years after the treatment was stopped. Relapses were diagnosed by clinical methods, including the reappearance of lesions or presence of new anesthetic areas. All cases were confirmed by bacilloscopy, and a subset of 20 cases by skin biopsy. Four patients presented indeterminate leprosy (IL) and one patient borderline tuberculoid leprosy (BT) in the biopsy. The latter 5 demonstrated presence of intraneural bacilli; the remainder were LL. Two patients relapsed even with PCT treatment. The others were cured with supervised PCT. Predisposing factors for relapses were as follows: DDS monotherapy, irregular PCT with inadequate dosage, unsupervised treatment, treatment uncompliance, and inadequate relationship between the patient and the health staff. Inspections for relapse in leprosy is recommended for in all multibacillary patients that were treated with DDS. The clinical appearance of new lesions or new anesthetic zones, the bacilloscopy and skin biopsy, used together, are effective in establishing the presence of relapses.