Immune thrombocytopenic purpura (ITP) is an autoimmune bleeding disorder. Persons with the disease have too few platelets in the blood. ITP is sometimes called immune thrombocytopenic purpura or simply, immune thrombocytopenia. ITP occurs when certain immune system cells produce antibodies against platelets. Platelets help your blood clot by clumping together to plug small holes in damaged blood vessels. The antibodies attach to the platelets. The spleen destroys the platelets that carry the antibodies. In children, the disease sometimes follows a viral infection. In adults, it is more often a chronic (long-term) disease and can occur after a viral infection, with use of certain drugs, during pregnancy, or as part of an immune disorder. ITP affects women more often than men, and is more common in children than adults. The disease affects boys and girls equally. Symptoms can include any of the following: abnormally heavy menstruation, bleeding into the skin, often around the shins, causing a skin rash that looks like pinpoint red spots (petechial rash), easy bruising, nosebleed or bleeding in the mouth.