Does clofazimine prevent erythema nodosum leprosum (ENL) in leprosy? A retrospective study, comparing the experience of multibacillary patients receiving either 12 or 24 months WHO-MDT.

OBJECTIVE To compare the occurrence, duration and severity of ENL in leprosy patients treated with either 12 or 24 months of standard multi-drug therapy (MDT). MATERIALS AND METHODS STUDY POPULATION 296 patients treated with MDT for 2 years, between 1985 and 1992 and followed up as part of a relapse study; and 293 patients, treated between 1998 and 2004, with MDT for 1 year and also followed up as part of a relapse study. The Chi squared test and multiple logistic regression analysis were used to test for statistical significance. RESULTS ENL was not significantly more common, but it was longer-lasting and more severe in patients receiving only 12 months of MDT, as compared with those receiving 24 months treatment. A high BI at the start of treatment significantly increased the risk of severe ENL by a factor of between 6 and 12, while treatment with 12 instead of 24 months of MDT significantly increased the risk by a factor of between 3 and 10. CONCLUSIONS This study provides further evidence that a high initial BI is the key risk factor for ENL. It also suggests that the difference between these two cohorts in their experience of ENL as demonstrated in this study, may be related to the different amounts of clofazimine which the two cohorts were given in the early years of their treatment. Further studies are needed to determine whether clofazimine could be used more specifically to reduce the severity of ENL in the small group of patients at high risk for the condition.