Patient education: Immune thrombocytopenia (ITP) (The Basics)

What is immune thrombocytopenia? — Immune thrombocytopenia ("ITP") is a problem with the immune system that causes too few platelets. Platelets are blood cells that help blood to clot.

People with ITP have a lower-than-normal number of platelets because their immune system destroys their platelets. The immune system is the body's infection-fighting system. Doctors call a low platelet count "thrombocytopenia." Immune thrombocytopenia means that it is caused by your immune system.

Some people with ITP can bruise or bleed much more easily than normal. If the platelet count is very low, the bleeding can be serious.

ITP can happen in adults and children. In children, it sometimes happens after an infection.

●In children, the platelet count often gets better on its own.

●Adults might need medicines to block their immune system from destroying platelets. This is most important if the platelet count is very low.

What are the symptoms of ITP? — Some people with ITP have no symptoms. When people do have symptoms, they can have:

●Bleeding – This can include nosebleeds or blood-filled blisters inside the mouth. In people who get monthly periods, bleeding can be very heavy. Sometimes, there can be more serious bleeding, like bleeding in the brain or in other parts of the body.

●Bleeding in the skin – This could look like large bruises or tiny bruise-like dots on the feet and ankles.

Is there a test for ITP? — Partly. There is a test for the number of platelets in the blood, called the "platelet count." This is often done as part of a "complete blood count" ("CBC"). If your platelet count is low, ITP might be the cause. But there is no test that can tell for sure if the low platelet count is because of ITP or something else.

If a blood test shows that you have a low platelet count, your doctor or nurse will:

●Ask questions – They will ask about your symptoms and what medicines you are taking. They will also ask whether you had a normal platelet count in the past and whether any of your relatives have a low platelet count. If there is a chance that you could be pregnant, they will ask about this, too.

●Do an exam and order blood tests – This is to help figure out if another condition is causing the low platelet count. The main test is a CBC. It tells if the white blood cell count is also low. (White blood cells are infection-fighting cells.) It also shows if you have a condition called anemia.

In children, ITP is a common cause of a low platelet count. A child might get better on their own.

Adults might have tests for other causes of a low platelet count. If no other cause of a low platelet count is found, the diagnosis might be ITP. Some of the other tests might include:

●Other lab tests – These might include tests to check for infections (including HIV), measure vitamin levels, or look for other blood disorders. If you are taking certain medicines, you might get a blood test to see if 1 of the medicines is causing a low platelet count.

●Bone marrow test – This might be done in older adults. Bone marrow is the cells inside some of your bones. It makes all of the blood cells, including platelets. A bone marrow test is a procedure that involves numbing the hip bone and using a needle to take a tiny sample. Then, the sample is examined under a microscope.

How is ITP treated? — Treatment depends on the person's age, symptoms, and how low the platelet count is.

Children with ITP do not need treatment unless they have serious bleeding or a very low platelet count. For most children, ITP goes away on its own within 6 months. But doctors follow children with ITP closely to make sure that the ITP does not get worse or needs treatment.

Adults with a very low platelet count or bleeding will most likely need treatment. If the ITP is mild and there is no bleeding, treatment is usually not needed. For adults who do need treatment:

●The first treatment is a steroid medicine. Steroids block the immune system and stop it from destroying platelets.

●Steroids have some side effects that you will need to know about. Your doctor will talk to you more about this.

●Steroids can take several days to work. People who need a very fast increase in platelet count might be treated with a platelet transfusion (when you get platelets donated by someone else). Or they might get a medicine called intravenous immune globulin ("IVIG"). IVIG stops the body from destroying platelets.

If the ITP doesn't get better, there are other treatments. These include:

●Surgery to remove the spleen – The spleen is part of the body's immune system (figure 1). Removing the spleen often stops the immune system from destroying platelets.

●Other medicines that block the immune system, such as rituximab. This is given through a thin tube that goes into a vein, called an "IV."

●Medicines that help the body make more platelets. Some of these medicines can be given as a pill, and some are given as an injection.

If these treatments don't work, other treatments are available.

What else might I need to do? — Depending on your platelet count and symptoms, you might need to:

●Avoid certain sports or activities – If your platelet count is very low, it's important to limit physical activity and not play certain sports, especially contact sports. That's because accidents can cause bleeding. If you have a very low platelet count and you get hurt, you can have even more serious bleeding. You can do your usual sports and activities again when your platelet count gets to a safe level.

●Avoid taking certain medicines – Some medicines, such as aspirin and drugs called nonsteroidal antiinflammatory drugs ("NSAIDs"), make your platelets not work as well. This can make bleeding more likely. Drugs that thin your blood, or "anticoagulants," also increase your risk of bleeding. Your doctor or nurse will let you know which prescription and over-the-counter medicines to avoid.

What if I have ITP and want to get pregnant? — If you have ITP and want to get pregnant, tell your doctor or nurse.

Most people with ITP can have a normal pregnancy and delivery. But you might need to be watched more closely or take certain medicines, especially around the time of delivery.

Your baby's platelet count might need to be tested as well. This is because there is a small chance that your baby could also have a low platelet count for a short time after birth. This does not mean that the baby has ITP, but it is important to check the baby's platelet count.

More on this topic

Patient education: Complete blood count (CBC) (The Basics)
Patient education: Splenectomy (The Basics)
Patient education: Managing increased bleeding risk (The Basics)
Patient education: Intravenous immune globulin (IVIG) (The Basics)

Patient education: Heavy or prolonged menstrual bleeding (menorrhagia) (Beyond the Basics)