Acquired hypogammaglobulinemia should always be considered during the evaluation of a patient with a suspected antibody deficiency Chronic corticosteroid use, antiepileptic drugs, and rituximab therapy, malignancies such as chronic lymphocytic leukemia, or lymphomas, nephrotic syndrome, protein-losing enteropathy and congenital lymphangiectasis, as well as HIV infection are considered as common causes of secondary hypogammaglobulinemia Headaches are a typically associated with intravenous immunoglobulin infusions Slowing or stopping the infusion for 15–30 minutes can reverse most of the acute reactions associated with IVIG infusion Adequate hydration or prescribing acetaminophen or NSAIDs are among options to prevent headaches during IVIG treatment