Idiopathic thrombocytopenic purpura

Eighty diseases in this category have been identified. People with idiopathic thrombocytopenic purpura (ITP) bleed under the skin, causing a kind of purple bruise to spread across the body. Other symptoms can include tiny red spots on the skin (petechiae) and nosebleeds. The condition is mild in the majority of cases. The disease is considered chronic when it has lasted more than 6 months.

Thrombocytopenia refers to decrease in blood platelets. Purpura refers to the purplish-looking areas of the skin and mucous membranes (such as the lining of the mouth) where bleeding has occurred as a result of decreased platelets.

Approximately 100,000 people in the USA have ITP. In adults, about two to three times more women have the disease than men. In children, the ratio is about even. It affects all age groups. The percentage rate of ITP cases is increasing. Each year there are approximately 20,000 new cases in the USA, or about 10 to 125 per million people. It is linked with viral diseases, such as mumps, rubella and measles, which it may follow.