What Is Idiopathic Thrombocytopenic Purpura?

Idiopathic thrombocytopenic purpura (ITP) is a bleeding condition in which the blood doesn't clot as it should. This is due to a low number of blood cell fragments called platelets (PLATE-lets).

Platelets also are called thrombocytes (THROM-bo-sites). They're made in your bone marrow along with other kinds of blood cells. Platelets stick together (clot) to seal small cuts or breaks on blood vessel walls and stop bleeding.

"Idiopathic" (id-ee-o-PATH-ick) means that the cause of the condition isn't known. "Thrombocytopenic" (throm-bo-cy-toe-PEE-nick) means there's a lower than normal number of platelets in the blood. "Purpura" (PURR-purr-ah) refers to purple bruises caused by bleeding under the skin.

Overview

People who have ITP often have purple bruises that appear on the skin or on the mucous membranes (for example, in the mouth). The bruises mean that bleeding has occurred in small blood vessels under the skin.

A person who has ITP also may have bleeding that results in tiny red or purple dots on the skin. These pinpoint-sized dots are called petechiae (peh-TEE-kee-ay). Petechiae may look like a rash.

Petechiae and Purpura

The photograph shows petechiae (red/purple dots) and purpura (bruises) in the skin. Bleeding under the skin causes the purple, brown, and red color of the petechiae and purpura.

People who have ITP also may have nosebleeds, bleeding from the gums when they have dental work done, or other bleeding that's hard to stop. Women who have ITP may have menstrual bleeding that's heavier than usual.

More extensive bleeding can cause hematomas (he-mah-TO-mas). A hematoma is a collection of clotted or partially clotted blood under the skin. It looks or feels like a lump.

Bleeding in the brain as a result of ITP is very rare, but can be life threatening if it occurs.

In most cases, an autoimmune response is believed to cause ITP. Normally your immune system helps your body fight off infections and diseases. But if you have ITP, your immune system attacks and destroys its own platelets. The reason why this happens isn’t known.

ITP can't be passed from one person to another.

Types of Idiopathic Thrombocytopenic Purpura

There are two types of ITP: acute (temporary or short-term) and chronic (long-lasting).

Acute ITP generally lasts less than 6 months. It mainly occurs in children, both boys and girls, and is the most common type of ITP. Acute ITP often occurs after an infection caused by a virus.

Chronic ITP is long-lasting (6 months or longer) and mostly affects adults. However, some teenagers and children can get this type of ITP. Chronic ITP affects women 2 to 3 times more often than men.

Treatment depends on how severe the bleeding symptoms are and the platelet count. In mild cases, treatment may not be needed.

Outlook

For most children and adults, ITP isn't a serious or life-threatening condition.

Acute ITP in children often goes away on its own within a few weeks or months and doesn't return. In 80 percent of children who have ITP, the platelet count returns to normal within 6 to 12 months. Treatment may not be needed.

A small number of children, about 5 percent, whose ITP doesn't go away on its own may need to have further medical or surgical treatment.

Chronic ITP will vary with each individual and can last for many years. Even people who have severe forms of chronic ITP can live for decades. Most people who have chronic ITP are able at some point to stop treatment and keep a safe platelet count.

Other Names for Idiopathic Thrombocytopenic Purpura

• Immune thrombocytopenic purpura
• Autoimmune thrombocytopenic purpura

What Causes Idiopathic Thrombocytopenic Purpura?

In most cases, it's believed that an autoimmune response causes idiopathic thrombocytopenic purpura (ITP).

Normally, the immune system makes antibodies (proteins) to fight off germs or other harmful things that enter the body. In ITP, however, the immune system attacks and destroys the body's platelets by mistake. Why this happens isn't known.

Children who get acute (short-term) ITP often have had recent viral infections. It's possible that the infection somehow "triggers" or sets off the immune reaction that leads to ITP in these children. ITP in adults, on the other hand, doesn't seem to be linked to infections.

Who Is At Risk for Idiopathic Thrombocytopenic Purpura?

Both children and adults can develop idiopathic thrombocytopenic purpura (ITP).

Children usually get the acute (short-term) type of ITP. Acute ITP often develops after an infection caused by a virus. Adults tend to get the chronic (long-lasting) type of ITP. Women are 2 to 3 times more likely than men to get chronic ITP.

ITP is a fairly common blood disorder, with 50 to 150 new cases per every 1 million people each year; about half of these cases are children. However, the number of cases of ITP is rising because routine blood tests that can detect a low platelet count are being done more often.

ITP can't be passed from one person to another.

What Are the Signs and Symptoms of Idiopathic Thrombocytopenic Purpura?

Having a low platelet count doesn’t cause symptoms. However, the bleeding that a low platelet count can cause may have the following signs and symptoms:

• Pinpoint red spots on the skin that often are found in groups and may look like a rash. The spots, called petechiae, are due to bleeding under the skin.
• Bruising or purplish areas on the skin or mucous membranes (such as in the mouth) due to bleeding under the skin. The bruises may occur for no known reason. This type of bruising is called purpura. More extensive bleeding can cause hematomas. A hematoma is a collection of clotted or partially clotted blood under the skin. It looks or feels like a lump.
• Nosebleeds or bleeding from the gums (for example, when dental work is done).
• Blood in the urine or stool (bowel movement).

Any kind of bleeding that's hard to stop could be a sign of ITP. This includes menstrual bleeding in women that’s heavier than usual.

Bleeding in the brain is rare, and the symptoms of bleeding in the brain may vary in severity.

A low number of platelets doesn't cause pain, fatigue (tiredness), problems concentrating, or any other symptoms.

How Is Idiopathic Thrombocytopenic Purpura Diagnosed?

Your doctor will diagnose idiopathic thrombocytopenic purpura (ITP) based on your medical history, a physical exam, and test results.

Your doctor will want to make sure that your low platelet count isn’t due to another condition (such as an infection) or a side effect of medicines you're taking (such as chemotherapy medicines or aspirin).

Medical History

Your doctor may ask about:

• Your signs and symptoms of bleeding and any other signs or symptoms you're having
• Whether you have illnesses that could lower your platelet count or cause bleeding
• Medicines or any other over-the-counter supplements or remedies you take that could cause bleeding or lower your platelet count

Physical Exam

Your doctor will give you a physical exam and look for signs of bleeding and infection. For example, your doctor may look for pinpoint red spots on the skin and bruising or purplish areas on the skin or mucous membranes. These are signs of bleeding under the skin.

Diagnostic Tests

You'll likely have blood tests to check your platelets. These tests usually include:

• A complete blood count. This test shows the numbers of different kinds of blood cells, including platelets, in a small sample of your blood. In ITP, the red and white blood cell counts are normal.
• A blood smear. During this test, some of your blood is put on a slide. A microscope is then used to look at your platelets and other blood cells. In ITP, the number of platelets is lower than normal.

You also may have a blood test to check for the antibodies that attack platelets.

If blood tests show that you have a low number of platelets, your doctor may recommend more tests to confirm a diagnosis of ITP. For example, bone marrow tests may be used to see whether your bone marrow is making platelets.

Some people who have mild ITP have few or no signs of bleeding. These people may be diagnosed only after a blood test done for another reason shows that they have a low platelet count.

How Is Idiopathic Thrombocytopenic Purpura Treated?

Treatment for idiopathic thrombocytopenic purpura (ITP) is based on how much and how often you’re bleeding and your platelet count. In some cases, treatment may not be needed.

Medicines often are used as the first course of treatment. Treatments used for children and adults are similar.

Adults with ITP who have very low platelet counts or problems with bleeding often are treated. Adults who have milder cases of ITP may not need any treatment, other than watching their symptoms and platelet counts.

The acute (short-term) type of ITP that occurs in children often goes away within a few weeks or months. Children who have bleeding symptoms, other than merely bruising (purpura), usually are treated.

Children who have milder cases of ITP may not need treatment other than monitoring and followup to make sure platelet counts return to normal.

Medicines

If adults or children who have ITP need treatment, medicines often are tried first. Corticosteroids (cor-ti-co-STEER-roids), such as prednisone, are commonly used to treat ITP.

These medicines, called steroids for short, help increase your platelet count by lowering the activity of your immune system. However, steroids have a number of side effects, and some people relapse (get worse) when treatment ends.

The steroids used to treat ITP are different from illegal steroids taken by some athletes to enhance performance. Corticosteroids aren't habit-forming, even if you take them for many years.

Some medicines used to help raise the platelet count are given through a needle inserted into a vein. These medicines include immune globulin and anti-Rh (D) immunoglobulin.

Medicines also may be used along with a procedure to remove the spleen, called splenectomy (splee-NECK-tuh-mee).

If steroids, immunoglobulins, or splenectomy don’t help, two newer medicines—eltrombopag and romiplostim—can be used to treat ITP.

Removal of the Spleen (Splenectomy)

If necessary, the spleen will be removed surgically. This organ is located in the upper left abdomen. The spleen is about the size of a golf ball in children and a baseball in adults.

The spleen makes antibodies (proteins) that help fight infection. In ITP, these antibodies destroy platelets.

If ITP hasn't responded to steroids, removing the spleen will reduce the destruction of platelets. However, it also may make you more likely to get certain infections. Before you have the surgery, your doctor may give you vaccines to help prevent these infections.

If your spleen is removed, your doctor will explain what steps you can take to help avoid infections and what symptoms to watch for.

Other Treatments

Platelet Transfusions

Some people with ITP who have severe bleeding may need to have platelet transfusions and be hospitalized. Some people will need a platelet transfusion before having surgery.

For a platelet transfusion, donor platelets from a blood bank are injected into the recipient's bloodstream. This increases the platelet count for a short time.

For more information on platelet transfusions, see the Diseases and Conditions Index Blood Transfusion article.

Treating Infections

Some infections can briefly lower a person's platelet count. If a person who has ITP has an infection that can lower his or her platelet count, treating the infection may help increase the platelet count and reduce bleeding problems.

Stopping Medicines

If a person who has ITP is taking medicine that can lower his or her platelet count or cause bleeding, stopping the medicine can sometimes help increase the platelet count or prevent bleeding.

For example, aspirin and ibuprofen are common medicines that increase the chance of bleeding. If you have ITP, your doctor may suggest that you avoid these medicines.

How Can Idiopathic Thrombocytopenic Purpura Be Prevented?

You can't prevent idiopathic thrombocytopenic purpura (ITP), but you can prevent its complications.

• Talk to your doctor about which medicines you can take. Your doctor may advise you to avoid medicines such as aspirin or ibuprofen that can affect your platelets and increase your risk of bleeding.
• Protect yourself from injuries that can cause bruising or bleeding.
• Seek treatment right away if you develop any infections. Report any symptoms of infection, such as a fever, to your doctor. This is very important for people with ITP who have had their spleens removed.

Living With Idiopathic Thrombocytopenic Purpura

If you have idiopathic thrombocytopenic purpura (ITP), you can take steps to prevent complications. Lifestyle changes and ongoing care can help you manage the condition.

Lifestyle Changes

If you have ITP, try to avoid injuries, especially head injuries, that can cause bleeding in the brain. For example, don’t participate in contact sports such as boxing, football, or karate. Other sports, such as skiing or horseback riding, also put you at risk for injuries that can cause bleeding.

Some safe activities are swimming, biking, and walking. Ask your doctor about physical activities that are safe for you.

Take precautions such as regular use of seatbelts and wearing gloves when working with knives and other tools.

If your child has ITP, ask his or her doctor whether you need to restrict your child's activities.

Ongoing Care

Find a doctor, preferably a hematologist, who is familiar with treating people who have ITP. Hematologists are doctors who specialize in diagnosing and treating blood diseases and disorders. Discuss with your doctor how to manage ITP and when to seek medical care.

Talk to your doctor before taking prescription and over-the-counter medicines and nutritional supplements. Some medicines and supplements can affect platelets and increase your chance of bleeding. Common examples are aspirin or ibuprofen.

Tell your doctor about all of the over-the-counter medicines you take, including vitamins, supplements, and herbal remedies. These products may contain substances that increase your risk of bleeding.

Watch for symptoms of infection, such as a fever, and report them to your doctor promptly. If you've had your spleen removed, you may be more likely to become ill from certain types of infection.

Idiopathic Thrombocytopenic Purpura in Pregnancy

In women who are pregnant and have ITP, the ITP usually doesn't affect the baby. However, some babies born to mothers who have ITP are born with or develop low numbers of platelets soon after birth.

Their platelet counts almost always return to normal without any treatment. Treatment can speed the recovery in the few babies whose platelet counts are very low.

Treatment for ITP during pregnancy depends on a woman's platelet count. If treatment is needed, the doctor will take a close look at the possible effects of the treatment on the unborn baby.

Women who have milder cases of ITP usually can go through pregnancy without treatment. Pregnant women who have very low platelet counts or a lot of bleeding are more likely to have serious heavy bleeding during delivery or afterward. To prevent serious bleeding, these women usually are treated.

Key Points

• Idiopathic thrombocytopenic purpura (ITP) is a bleeding condition in which the blood doesn't clot as it should. This is due to a low number of blood cell fragments called platelets.
• Platelets stick together (clot) to seal small cuts or breaks on blood vessel walls and stop bleeding.
• There are two types of ITP. Acute ITP is a short-term illness that mainly affects children and often occurs after a viral infection. Most children get well quickly without any treatment. Adults who have ITP most often have chronic (long-lasting) ITP. Symptoms can vary a great deal, and some adults who have mild ITP don't need treatment.
• In most cases, an autoimmune response is believed to cause ITP. Normally your immune system helps your body fight off infections and diseases. But if you have ITP, your immune system attacks and destroys its own platelets. The reason why this happens isn't known.
• ITP can't be passed from one person to another.
• ITP can affect children and adults of all ages. Women are 2 to 3 times more likely than men to get chronic ITP.
• People who have ITP may have signs of bleeding, such as bruises (purpura) that appear for no reason or tiny red dots (petechiae) that are visible on the skin.
• Bleeding in ITP also occurs in the form of nosebleeds, bleeding gums, menstrual bleeding that’s heavier than usual, or other bleeding that's hard to stop. Bleeding in the brain as a result of ITP is very rare, but it can be life threatening when it occurs.
• ITP is diagnosed based on your medical history, a physical exam, and results from blood tests.
• Treatment for ITP is based on how much and how often you’re bleeding and your platelet count. Medicines often are used as the first course of treatment. Treatments used for children and adults are similar.
• The spleen is sometimes removed if treatment with medicine fails to keep the platelet level high enough to prevent bleeding.
• You can't prevent ITP, but you can prevent its complications. Talk to your doctor about what medicines are safe for you, protect yourself from injuries that can cause bruising or bleeding, and seek treatment if any signs of infection develop.
• For most children and adults, ITP isn't a serious or life-threatening condition. Even people who have severe forms of chronic ITP can live for decades.

Links to Other Information About Idiopathic Thrombocytopenic Purpura

Non-NHLBI Resources

• Idiopathic Thrombocytopenic Purpura (MedlinePlus)

Clinical Trials

• Current Research (ClinicalTrials.gov)
• NHLBI Pediatric Clinical Trials
• Patient Recruitment for Studies Conducted by the NHLBI, NIH