Pediatric thrombocytopenic purpura is a bleeding disorder caused by a lack of platelets in the blood. Thrombocytopenia is usually caused by the body's immune system mistakenly destroying platelets. Children with thrombocytopenia will bruise easily and may have other bleeding problems. Therefore, the basic principle in caring for children with thrombocytopenic purpura is to prevent bleeding events in children.

Idiopathic thrombocytopenic purpura is an immune disorder in which the blood does not clot normally. This condition is now commonly known as immune thrombocytopenia (ITP).

Although drugs are a common cause of acute immune-mediated thrombocytopenia in humans, drug-induced thrombocytopenia is often not initially recognized. Typically, drug-induced thrombocytopenia occurs 1 to 2 weeks after starting a new drug or abruptly after a single dose when a previous drug has not been used continuously. However, severe drug-induced thrombocytopenia can occur shortly after starting antiplatelet or antithrombotic drugs.