Skin sensitivity of schoolchildren in Yugoslavia to different mycobacterial sensitins.

Schoolchildren were tested on one arm with human sensitin RT 23 and simultaneously on the other arm with one of the sensitins prepared from atypical mycobacteria: nonchromogen, RS 10; photochromogen, RS 30; or scotochromogen, RS 64. Testing was made with low and with high doses of sensitins. Because of the extensive BCG vaccination programme in the country the number of persons not previously vaccinated with BCG in the study was very small. However, no indication of the prevalence of higher skin sensitivity to atypical sensitins than to human sensitin was foun. Almost all the persons previously vaccinated with BCG who reacted to human sensitin showed a cross-reaction to the atypical sensitins. The cross-sensitivity was more pronounced in persons who were tested with scotochromogen sensitin and when they were tested with higher doses.