In acute ITP it is postulated that the antibodies, produced in response to an acute viral infection or other antigenic stimulation, attach to glycoprotein IIb IIIa on the surface of the platelets by molecular mimicry. These opsonized platelets selectively undergo phagocytosis by the macrophages of the spleen and RES. This increased and premature destruction of antibody coated platelets leads to a temporary state of thrombocytopenia.

After a period of weeks to months, the antibody production declines leading to less opsonization of platelets and a relative increase in platelet count.

Fact: Approximately 80% of children with acute ITP will spontaneously recover and have normal platelet counts at 6 months from diagnosis.