Erythema nodosum leprosum in Nepal: a retrospective study of clinical features and response to treatment with prednisolone or thalidomide

[[[ Introduction: ]]] Erythema nodosum leprosum (ENL) is an inflammatory reaction, which may occur in the course of leprosy and may result in nerve function impairment and subsequent disability. [[[ Methods: ]]] This retrospective study explores demographic and disease specific parameters. Severity of ENL was assessed using the Reaction Severity Scale (RSS). Records of 94 patients were reviewed. The study reports also on the treatment of 76 of these patients who were treated with prednisolone alone or thalidomide in addition to prednisolone. RESULTS Thirty percent of patients presented with ENL at time of diagnosis; 41% developed ENL-reaction in the first year of MDT. Forty-eight percent of patients were treated for ENL-reaction for less than 12 months; 13% for more than 5 years. High RSS-scores correlated with a longer duration of treatment. In group A (prednisolone) 51.7% and in group B (prednisolone and thalidomide) 76.6% of patients were male. Age, leprosy classification, delay of multidrug treatment (MDT) and interval between MDT and first ENL-symptoms did not differ significantly in both groups. Median duration of ENL-treatment was 15 months in group A versus 38 months in group B (P < 0.001). At the start of treatment, ENL-reaction was less severe in group A (RSS = 12) than in group B (RSS = 18; P = 0.003). [[[ Discussion: ]]] ENL-symptoms may be of help in the early diagnosis and adequate treatment of ENL. Characterisation of (sub) groups of patients with ENL based on presence and severity of symptoms is important for future prospective studies to better evaluate the efficacy of interventions.