The drug of choice is intravenous IgG (IVIG) for treatment of ITP. The side effects are flu-like symptoms, and in rare cases aseptic meningitis. Another option is intravenous anti-D, if the child is rhesus positive. Anti-D is primarily used in North America. The effect of Anti-D is comparable with IVIG when considering the time it takes to bring the platelet count above 50,000/μL. Anti-D also causes flu-like symptoms. Establishing an i.v. access is a disadvantage to both IVIG and anti-D. For both treatments mechanism of action is not finally described.