Reflections on some aspects of leprosy among children in Brazil and in other countries

The authors discuss the classification, clinical aspects, lepromin reactivity, and epidemiologic features of leprosy among children. The most frequent characteristics of each form of leprosy are described. Lepromatous leprosy is less frequent among children in countries of low endemicity and more frequent, even in the most advanced forms, in hyperendemic regions. Borderline forms are rare. In a large number of cases the initial manifestations are those of the indeterminate form and, in an even larger number of cases, of the tuberculoid pole. The evolution from indeterminate to the tuberculoid pole very frequently occurs in a few months or within less than one year. With respect to epidemiology, the authors consider the general frequency of leprosy among children and the frequency of each form of leprosy among children and adults. Data from surveys carried out in Brazil and other countries are presented. Children have a potential for the rapid development of immunoresistance and consequently of lepromin-positivity, and therefore only a few of them eventually develop lepromatous leprosy. This explains the low indices of lepromatous leprosy (approximately 5%) even in hyperendemic areas. Finally, they discuss the factors that may be responsible for the clinical manifestations of leprosy and their characteristics among children.