Case Presentation:   A 47-year-old woman with history of immunoglobulin G (IgG) deficiency presented with severe headache, fever, vomiting, neck pain and photophobia. On the day prior to admission, she received first dose of Intravenous immunoglobulin (IVIG) infusion for recurrent bacterial infections refractory to antibiotic prophylaxis. On examination, her temperature was 100 °F and vital [...]