Disseminated BCG disease with unusual manifestations

Bacille Calmette-Guérin (BCG) vaccine - although considered safe in infants, is associated with complications - ranging from local and regional complications to the disseminated form of BCG disease. We report an interesting case of fever of unknown origin in an infant, closely mimicking hematological malignancy and Langerhans cell histiocytosis (LCH). Investigations revealed disseminated BCG disease with underlying immunodeficiency.