Variability of tuberculin reactions in adolescents may be represented by changes of a negative tuberculin test to a positive or false one, then to a positive test. Adolescents primarily infected with tuberculosis have predisposing factors: inadequate immunoprophylaxis contact with tuberculosis patients, discord in physical development, hyperergic sensitivity to tuberculin, which can determine a further course of tuberculosis infection. The variability of tuberculin reactions in adolescents is characterized by changed immunological responsiveness as higher immunospecific parameters and lower nonspecific responsiveness parameters, as well as decreased attention; there is a trend for frequent development of primary infection in persons having character accentuation. The aforesaid allows the variability of tuberculin reactions to be regarded as "minor disease".