Snapshot A 4-year-old boy is brought to the emergency department with a fever, rigors, hypotension, and dyspnea following BCG vaccine administration. When an IV was attempted, she began bleeding profusely from the site. A CXR showed interstitial infiltrates, raising suspicion for pneumonitis. Blood specimens show acid-fast bacilli. Culture are pending. Empiric treatment with fluoroquinolones is started. Introduction IL-12 function login to view 4 more bullets Mutations in IL-12 receptors resulting in decreased IFN-γ Genetics login to view 1 more bullet Pathogenesis login to view 3 more bullets Presentation Symptoms login to view 9 more bullets Evaluation Serology login to view 1 more bullet Differential Diagnosis IFN-γ receptor deficiencies Hyper IgE syndrome Treatment Antibiotics/antifungals as infections arise IFN-γ therapy may help Prognosis, Prevention, and Complications Prognosis login to view 2 more bullets Complications login to view 1 more bullet