Dual Fates: The Deadly Intersection of BCGiosis and Primary Immunodeficiency in Two Children

Bacillus Calmette-Guerin (BCG) vaccine related complications are rare and range from benign local BCGitis (regional lymphadenitis due to BCG) to disseminated BCG disease (BCGiosis), a potentially lethal disseminated disease. Incidence of disseminated BCGiosis is very rare- 1 in 3.4 million. We present two such rare cases. A 7-month-old male child presented with complaints of red raised lesions all over body since 15 days with fever and chills. There was a nonhealing ulcer at the BCG scar site that prompted us to evaluate for BCGiosis and workup for immunodeficiency. Gene-expert of tissue and gastric lavage was positive for Mycobacterium tuberculosis . Immunodeficiency workup revealed severe combined immunodeficiency disease (SCID). The patient was started on antitubercular therapy (ATT), but the child succumbed due to respiratory failure on day 3 of ATT drugs. A 9-month-old male child had a left axillary swelling noticed by the parents for 15 days. On enquiry, there was a red raised lesion over the BCG scar site with the development of crust at the age of 5 months. We suspected localized BCGitis and accordingly evaluated for immunodeficiency. The studies revealed chronic granulomatous disease (CGD). The patient was started on ATT and planned for granulocyte infusions but succumbed. BCGosis as well as BCGitis should prompt clinicians to evaluate for immunodeficiency to determine the underlying immune defect as done in our cases. BCG-related infections are often a way of revealing immunodeficiency. Therefore, a careful family history and an extended neonatal screening including SCID and CGD should be carried out to prevent BCG vaccine-related mortality in these patients.