Cutaneous response to 2 and 10 units of tuberculin in infants
O'Ryan, M.; Gómez, T.; Tapia, J.; Sáez, M.; Talesnik, E.; Rivero, S.; Vilches, S.; Capdeville, V.
Revista Chilena de Pediatria 61(3): 133-138
1990
ISSN/ISBN: 0370-4106 PMID: 2077584 Document Number: 358192
A study was done in 322 healthy, well nourished infants, 3 to 18 months old from day care centers of metropolitan Santiago, Chile, that were given BCG immunization in their neonatal period: 304 (94.4%) of them showed BCG scars and were included in a double blind open study, to determine the cutaneous responses to 2 TU and 10 TU tuberculin (PPD). There were no differences in the mean size of cutaneous reactions nor in percent positive responses (greater than or equal to 10 mm), but cutaneous reactions greater than or equal to 15 mm were more frequent in infants tested with PPD 10 TU. In 184 out of 304 infants (60.5%) tuberculin reactions were negative (less than or equal to 10 mm). Eighteen out of 322 infants (5.6%) that didn't show BCG scars were injected with PPD 2 TU: tuberculin reactions sized 6 to 9 mm were recorded in 3/18 of these infants but none of them attained 10 mm. Fifty five infants whose tuberculin reactions were 5 mm or less were retested: a booster effect was likely from the appearance of enhanced dermal response after a second tuberculin test done with the same or higher tuberculin strength than the first one in 12/47 of these infants with BCG scar (25%) and in only 1/8 such subjects without BCG scar.