Idiopathic thrombocytopenic purpura (ITP)

Alternative names:

immune thrombocytopenic purpura; ITP

Definition:

A bleeding disorder resulting from a shortage of platelets with characteristic bleeding under the skin.

Causes, incidence, and risk factors:

The disease is caused when the spleen and lymph tissue produce antibodies against platelets. The antibodies destroy the platelets in the spleen.

Skin hemorrhage, easy bruising, abnormal menstrual bleeding, or sudden and severe loss of blood from the gastrointestinal tract may occur. Usually, no other abnormal findings are present. In children, the disease is sometimes preceded by a viral infection and runs its course without treatment. In adults, it is usually a chronic disease and rarely follows a viral infection.

ITP affects women more frequently than men and is more common in children than adults. There is no sex difference in children. Risk factors are unknown. The incidence is 1 out of 10,000 people.