Abstract :
Leprosy is a chronic granulomatous disease caused by Mycobacterium leprae, mainly affecting the skin and peripheral nerves. Leprosy reaction is an immunological complication of leprosy and consists of two types of reactions. Type 1 leprosy is called a reversal reaction (RR), and type 2 is called erythema nodosum leprosum (ENL). Indonesia has the third-highest number of cases of leprosy infection globally, after India and Brazil. To determine the characteristics of leprosy reactions at 13 teaching hospitals in Indonesia for three years, from 2018 to 2020. The highest proportion of cases were found in the age group >14 years (95.33%), while children aged ≤14 years were only 4.6% of the total cases. Leprosy is more common in men (1,642 cases). Multibacillary leprosy is more common (86.19%). Of 2,461 cases, as many as 843 (34.25%) had leprosy reactions, with type 2 reactions being more common than 500 cases (59.31%). Of 13 cities, the most cases of leprosy reaction were reported in Jakarta, with 396 cases with 168 cases (67.47%) of type 1 leprosy reaction. Lucio phenomenon in this study only occurred in 1.9% of 843 cases of leprosy reactions. Leprosy is more common in adolescents and adults, as well as in males. The most common type of leprosy in Indonesia is multibacillary leprosy. Overall, type 2 leprosy reactions in Indonesia are more common than type 1 leprosy reactions.