After immunoglobulin therapy's discovery and description in Pediatrics in 1952, weekly intramuscular injections of immunoglobulin (IMIG) were the norm until intravenous formulations (IVIG) began to be introduced in the 1980s [REF].
Although intravenous was the preferred route for immunoglobulin therapy for many years, in 2006 the FDA approved the first preparation of immunoglobulin that was designed exclusively for subcutaneous use [REF].