Disseminated Bacille Calmette-Guerin (BCG) disease in an infant with severe combined immunodeficiency.

Bacille Calmette-Guerin (BCG) vaccine is administered to all newborns in countries where tuberculosis is still endemic. It is a live attenuated vaccine and considered quite safe in immunocompetent children. Disseminated BCG disease is the most serious complication seen only in individuals with underlying primary or secondary immunodeficiencies. We report a case of disseminated BCG disease in an infant with Severe Combined Immunodeficiency (SCID) who received BCG administration prior to diagnosis of SCID.