Abstract: Background: Erythema nodosum leprosum may appear before, during or after treatment of leprosy and is one of the main factors for nerve damage in patients. When it occurs or continues to occur after treatment, it may indicate disease recurrence and a new treatment may be instituted again. Objective: To evaluate the retreatment of patients with multibacillary leprosy who underwent standard treatment with multidrug therapy, but developed or continued to present reactions of erythema nodosum leprosum and/or neuritis 3-5 years after its end. Method: For this objective, a new treatment was performed in 29 patients with multibacillary leprosy who maintained episodes of erythema nodosum and/or neuritis 3-5 years after conventional treatment. Results: In general, we observed that 27 (93.10%) had no more new episodes after a follow up period of eight months to five years. In five of these patients the reason for the retreatment was the occurrence of difficult-to-control neuritis, and that has ceased to occur in all of them. Study limitations: Small number of patients.. Conclusion: In the cases observed, retreatment was an effective measure to prevent the occurrence of erythema nodosum leprosum and/or persistent neuritis.

BACKGROUND: Leprosy can have its course interrupted by type 1 and 2 reactional episodes, the last named of erythema nodosum leprosum (ENL). Thalidomide has been the medication of choice for the control of ENL episodes since 1965. OBJECTIVES: These episodes can repeat and cause damages to the patient. In order to prevent these episodes, an extra dose of 100 mg/day thalidomide was used during six months, followed by a follow-up period of six more months after thalidomide discontinuation. METHODS: We included 42 patients with multibacillary (MB) leprosy who had episodes of ENL. They were male and female patients aged between 18 and 84 years. RESULTS: Of the 42 patients, 39 (92.85%) had the lepromatous form and three (7.15%) had the borderline form. We found that 100% of patients had no reactional episode during the use of the drug. During the follow-up period after thalidomide discontinuation, 33 (78.57%) patients had no reactional episode and nine (21.43%), all of them with the lepromatous form, had mild episodes, which were controlled using non-steroidal anti-inflammatory. There were no thalidomide-related side effects. CONCLUSION: A maintenance dose of 100 mg/day of thalidomide showed to be effective to prevent repeated type 2 reactional episodes of ENL.