Thalidomide in the treatment of erythema nodosum leprosum (ENL) in an outpatient setting: A five-year retrospective analysis from a leprosy referral centre in India

Erythema nodosum leprosum (ENL), or type 2 lepra reaction, is a multi-system immune-mediated complication in patients with multibacillary leprosy, frequently associated with chronicity and recurrences. Management of ENL requires high doses of oral corticosteroids, which may not be universally effective and pose serious adverse effects. Thalidomide has proven to be a steroid-sparing agent and is useful in controlling the reactions. However, many centres do not employ it in outpatient settings due to adverse effects and teratogenicity risk. Hence, we studied the feasibility of treating ENLs and reported the therapeutic outcome.This is a five-year record-based analysis of ENL leprosy patients treated with thalidomide, includingdescriptive statistics of demographic variables. Clinical characteristics were stratified by treatment compliance status (yes/no). Incidence rates and rate ratios for recovery stratified by bacillary index, type of ENL presentation and MDT treatment status were calculated.Out of 102 ENL patients treated with thalidomide, 68 (66.7%) were compliant and improved. Among them, ENL recurrence was noted in 11(16.2%) patients. The commonest thalidomide side effect was pedal oedema (73.5%). Patients with bacillary index (BI) less than or equal to 4.0 had a 37% increase in the incidence of recovery. Patients with acute ENL were almost twice as likely to recover as those with chronic ENL. Also, the improvement was two and a half times greater among those who completed MDT as compared to those on MDT. The study showed that thalidomide treatment for patients with ENL is possible in outpatientclinics. We also successfully prevented pregnancies to a larger extent through counselling for contraception.We observed that early institution of thalidomide induces faster remission and prevents ENL recurrence.Author summary: Erythema nodosum leprosum (ENL), is an immune-mediated condition of leprosy.It is a multi-system disorder which can occurbefore, during or after completion of multidrug therapy for leprosy.ENL is often characterised by chronicity and recurrence. Management of ENL requires long-term oral corticosteroids which are associated with adverse effects.Thalidomide is an alternative to steroids, but many centres donot use it in their outpatient clinics due to the significant concern of drug-producing birth defects.This study provides additional evidence of the feasibility of thalidomide treatment in ENL at outpatient settings.