Introduction: Colombia is the country in America with the highest proportion of new cases leprosy with severe disability. To decrease such disability it is necessary to control these reactions, the main cause of nerve damage in leprosy. Objective: To describe the clinical and epidemiological characteristics and the treatment of patients with type 1 and 2 leprosy reactions who consulted the Centro Dermatológico Federico Lleras Acosta. Materials and methods: It is a descriptive study which included patients with clinical diagnoses of type 1 and 2 reactions who were seen in the center between 2003 and 2009. The town of origin of the patients, their age, clinical features and treatments were analysed. Results: We studied 96 reactions in 87 patients, 35 type 1 and 61 type 2 reactions; 75percent-flag-change of the patients came from the departments of Tolima, Cundinamarca, Santander and Boyacá; 77percent-flag-change of type 1 reaction occurred before the beginning of multidrug therapy for leprosy. The reactions that started after stopping the multidrug therapy were considered as a leprosy relapse. Conclusions: Correct identification of type 1 reaction by the general practitioner will allow the diagnosis of leprosy in a large percentage of patients. The type 1 reaction that begins after stopping the leprosy multidrug therapy may be a manifestation of a relapse of the disease.
