Idiopathic thrombocytopenic purpura (ITP) is a blood disorder characterized by a decrease in the number of platelets in the blood. Platelets are cells in the blood that help with clotting, and low levels of platelets can lead to bruising and bleeding. ITP is a rare autoimmune disorder that causes the immune system to destroy the blood-clotting platelets. The cause of ITP is not known, but it is due to an immune system error that may be triggered by viral infections. ITP can also be associated with pregnancy or other immune disorders such as rheumatoid arthritis or lupus.

ITP can affect both children and adults, and there are two forms of ITP: acute and chronic. Acute ITP usually affects young children, ages 2 to 6 years old, and the symptoms may follow a viral illness, such as chickenpox. Acute ITP usually starts suddenly and the symptoms usually disappear in less than 6 months, often within a few weeks. Treatment is often not needed, and the disorder usually does not recur. Chronic ITP is more common in adults and can last for months or years. People with chronic ITP may need treatment for the rest of their lives.

Symptoms of ITP may include easy bruising, bleeding into the skin that looks like tiny reddish-purple spots, also known as petechiae, and bleeding that is difficult to stop. In adults, an infection with HIV, hepatitis, or the bacteria that causes stomach ulcers, known as H. pylori, can cause ITP.

Treatment for ITP depends on the severity of the symptoms. People with ITP who arent bleeding and whose platelet count isnt too low might not need treatment. For worse symptoms, treatment might include medicines to raise platelet count or surg...