Case Presentation: Common variable immunodeficiency (CVID) is a primary immunodeficiency characterized by hypogammaglobulinemia and heterogenous manifestations. We present a 67-year-old woman admitted inpatient for fluctuating mental status changes along with intermittent fevers and diaphoresis for several months. Her medical history is notable for congestive heart failure, obstructive sleep apnea, and chronic abdominal pain in the [...]