What Causes Idiopathic Thrombocytopenic Purpura?
In most cases, it’s believed that an autoimmune response causes idiopathic thrombocytopenic purpura (ITP). Normally, the immune system makes antibodies (proteins) to fight off germs or other harmful things that enter the body. In ITP, however, the immune system attacks and destroys the body’s platelets by mistake. Why this happens isn’t known. Children who get acute (short-term) ITP often have had recent viral infections. It’s possible that the infection somehow “triggers” or sets off the immune reaction that leads to ITP in these children. ITP in adults, on the other hand, doesn’t seem to be linked to infections.