Idiopathic Thrombocytopenic Purpura (ITP)

What is ITP?
ITP stands for idiopathic thrombocytopenic purpura. "Idiopathic" means that the cause is unknown. "Thrombocytopenic" means the blood doesn't have enough platelets. "Purpura" means a person has excessive bruising. You may also hear ITP called "immune thrombocytopenic purpura."
In people with ITP, all of the blood cells are normal except for the blood platelets. Platelets are the tiny cells that seal minor cuts and wounds and form blood clots. A person with too few platelets bruises easily and bleeds for a long time after being injured. Tiny red dots on the skin, called petechiae (say "pe-TEEK-ee- ay") might also appear. When the platelet count is very low, the person with ITP might have nosebleeds that are hard to stop, or might have bleeding in the intestines.

What causes ITP?
The cause of ITP is not known. People with ITP form antibodies that destroy their blood platelets. Normally, antibodies are a healthy response to bacteria or viruses. In people with ITP, however, the antibodies attack the body's own blood platelets.

Who gets ITP?
There are 2 types of ITP. One type affects children, and the other type affects adults. In children, the usual age for getting ITP is 2 to 4 years of age. Most adults with ITP are young women, but it can occur in anyone. ITP does not run in families.

How does ITP affect children?
ITP is different in children than in adults. Most children with ITP have a very low platelet count that causes sudden bleeding. The usual symptoms are bruises and the tiny red dots on the skin. Nosebleeds and bleeding gums are also common.

How is ITP diagnosed?
Your doctor can diagnose ITP by asking questions about your health and doing a physical exam. Your doctor may take a blood sample and look at it under a microscope.

How is ITP treated in children?
Because most children recover with no treatment, many doctors recommend just watching them carefully and taking care of the bleeding symptoms. Children don't have to go to the hospital if good care is available at home. However, some doctors recommend a short treatment with prednisone pills or intravenous infusions (given in a vein) of gamma globulin to increase the platelet count more quickly. Both medicines have some side effects.

How does ITP affect adults?
In most adults, ITP lasts much longer than it does in children. At the time of diagnosis, most adults have noticed increased bleeding and easy bruising for several weeks, or even months. In women, increased menstrual blood flow is a major sign.
Many adults have only mild thrombocytopenia. In fact, quite a few people have no bleeding symptoms. They are only diagnosed with ITP when their blood is checked for another reason and a low blood platelet count is found.

How is ITP treated in adults?
Treatment of ITP in adults is aimed at increasing the blood platelet count. This is not the same as curing the disease. Patients may take prednisone for several weeks, even a month or longer. However, when the medicine is stopped, the platelet counts may get low again. If prednisone doesn't help enough, the spleen can be removed. The spleen makes most of the antibodies that destroy the blood platelets. It also destroys old or damaged blood cells. In an otherwise healthy young person, removal of the spleen is not a serious operation.

What about ITP in pregnant women?
Diagnosing ITP during pregnancy can be difficult, because platelet counts may be low for other reasons. About 5% of women have mildly low platelet counts at the end of a normal pregnancy. The cause of this is unknown. The platelet count goes back to normal right after delivery. A baby born to a mother with ITP may have a low blood platelet count a few days to a few weeks after birth. These babies are usually kept in the hospital for several days for observation (watching to make sure they are ok) before they go can home.
(AAFP)