Case report: Cyclophosphamide pulse therapy for chronic recalcitrant erythema nodosum leprosum.

Chronic recalcitrant erythema nodosum leprosum (ENL) or type 2 reaction (T2R) is a severe condition found in approximately 50% of multibacillary leprosy subjects. T2R is associated with important morbidities and may lead to several disabilities, not only due to nerve damage but also due to the prolonged use of corticosteroids, thalidomide, or immunosuppressors. We describe here four leprosy patients with chronic recalcitrant ENL treated with cyclophosphamide pulse therapy. All subjects had been on prednisone and thalidomide therapy for at least 30 months but showed inflammatory activity when doses were reduced. Pulse therapy with 1.0 g of cyclophosphamide was used every 4-6 weeks for a minimum of three applications. After pulse therapy, all cases presented total or partial regression of symptoms, and we were able to taper thalidomide and prednisone doses, with better control of ENL, avoiding further hospital admissions and disabilities. No side effects were observed during or after infusion therapy. Cyclophosphamide pulse therapy may be useful and safe to control chronic recalcitrant ENL.