Idiopathic thrombocytopenic purpura

Other Names: ITP; Autoimmune thrombocytopenic purpura; Thrombocytopenic purpura autoimmune

Idiopathic thrombocytopenic purpura (ITP) is a bleeding disorder characterized by too few platelets in the blood. This is because platelets are being destroyed by the immune system. In ITP, the blood doesn't clot as it should. This is due to a low number of blood cell fragments called platelets (PLATE-lets) or thrombocytes (THROM-bo-sites). Platelets are made in your bone marrow along with other kinds of blood cells. They stick together (clot) to seal small cuts or breaks on blood vessel walls and stop bleeding.

Cause

In most cases, an autoimmune response is thought to cause immune thrombocytopenia (ITP). Normally, your immune system helps your body fight off infections and diseases. In ITP, however, your immune system attacks and destroys your body's platelets by mistake. Why this happens isn't known. In some people, ITP may be linked to viral or bacterial infections, such as HIV, hepatitis C, or H. pylori. Children who have acute (short-term) ITP often have had recent viral infections. These infections may "trigger" or set off the immune reaction that leads to ITP.

Risk factors

Immune thrombocytopenia (ITP) is a fairly common blood disorder. Both children and adults can develop ITP. Children usually have the acute (short-term) type of ITP. Acute ITP often develops after a viral infection. Adults tend to have the chronic (long-lasting) type of ITP. Women are two to three times more likely than men to develop chronic ITP. 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.

Signs or symptoms

Without enough platelets, bleeding can occur inside the body (internal bleeding) or underneath or from the skin (external bleeding). Signs of bleeding may include: People who have ITP often have purple bruises called purpura (PURR-purr-ah). These bruises appear on the skin or mucous membranes (for example, in the mouth). Bleeding from small blood vessels under the skin causes purpura. People who have ITP also may have bleeding that causes 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. A collection of clotted or partially clotted blood under the skin that looks or feels like a lump. This is called a hematoma. Nosebleeds or bleeding from the gums (for example, during dental work). Blood in the urine or stool (bowel movement). A low platelet count doesn't directly cause pain, problems concentrating, or other symptoms. However, a low platelet count might be associated with fatigue (tiredness).

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  Petechiae on the lower extremities

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  Oral petechiae/purpura - lower lip

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  Petechia on the tongue in a person with platelets of 3 due to ITP

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  Petechia of the lower leg in a person with platelets of 3 due to ITP

For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. 80%-99% of people have these symptoms

• Thrombocytopenia(Low platelet count)
• Thromboembolism

30%-79% of people have these symptoms

• Arterial thrombosis(Blood clot in artery)
• Petechiae

5%-29% of people have these symptoms

• Bruising susceptibility(Bruise easily)
• Epistaxis(Bloody nose)
• Gastrointestinal hemorrhage(Gastrointestinal bleeding)
• Gingival bleeding(Bleeding gums)

1%-4% of people have these symptoms

• Cerebral hemorrhage(Bleeding in brain)

Diagnosis

You'll likely have blood tests to check your platelet count. These tests usually include: A complete blood count. This test checks the number of red blood cells, white blood cells, and platelets in your blood. In ITP, the red and white blood cell counts are normal, but the platelet count is low. A blood smear. For this test, some of your blood is put on a slide. A microscope is used to look at your platelets and other blood cells. You also may have a blood test to check for the antibodies (proteins) that attack platelets. If blood tests show that your platelet count is low, your doctor may recommend more tests to confirm a diagnosis of ITP. For example, bone marrow tests can show whether your bone marrow is making enough platelets. If you're at risk for HIV, hepatitis C, or H. pylori, your doctor may screen you for these infections, which might be linked to ITP. Some people who have mild ITP have few or no signs of bleeding. They may be diagnosed only if a blood test done for another reason shows that they have low platelet counts.

Treatment

Adults who have mild ITP may not need any treatment, other than watching their symptoms and platelet counts. Adults who have ITP with very low platelet counts or bleeding problems often are treated. Children who have mild ITP may not need treatment other than monitoring and followup to make sure their platelet counts return to normal. Medicines often are used as the first course of treatment for both children and adults. 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. However, steroids have many side effects. Some people relapse (get worse) when treatment ends. The steroids used to treat ITP are different from the illegal steroids that some athletes take to enhance performance. Corticosteroids aren't habit-forming, even if you take them for many years.

Other medicines also are used to raise the platelet count. Some are given through a needle inserted into a vein. These medicines include rituximab, immune globulin, and anti-Rh (D) immunoglobulin. Medicines also may be used with a procedure to remove the spleen called splenectomy (splee-NECK-tuh-mee).

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

The medication(s) listed below have been approved by the Food and Drug Administration (FDA) as orphan products for treatment of this condition.

• Immune Globulin Injection (Human) 10% Caprylate/Chromatography Purified (Brand name: Gammaked)
• Human immunoglobulin (human) (Brand name: Gammaplex)
• Immune globulin injection [human], 10% caprylate/chromatography purified (Brand name: Gamunex-C)
• Romiplostim (Brand name: Nplate)
• Immune globulin intravenous (human), 10% liquid (Brand name: Privigen)
• Eltrombopag (Brand name: Promacta)
• Fostamatinib disodium hexahydrate (Brand name: Tavalisse)
• Rho (D) immunoglobulin intravenous (human) (Brand name: WinRho SD)

Removal of the Spleen (Splenectomy)

children and a baseball in adults. The spleen makes antibodies (proteins) that help fight infections. In ITP, these antibodies destroy platelets by mistake. If ITP hasn't responded to medicines, removing the spleen will reduce the destruction of platelets. However, it also may raise your risk for infections. Before you have the surgery, your doctor may give you vaccines to help prevent 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 who have ITP with severe bleeding may need to have platelet transfusions and be hospitalized. Some people will need platelet transfusions 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 about platelet transfusions, go to the Health Topics Blood Transfusion article.

Treating Infections

Some infections can briefly lower your platelet count. Treating the infection may help increase your platelet count and reduce bleeding problems.

Stopping Medicines

Some medicines can lower your platelet count or cause bleeding. Stopping the medicine can sometimes help raise your platelet count or prevent bleeding. For example, aspirin and ibuprofen are common medicines that increase the risk of bleeding. If you have ITP, your doctor may suggest that you avoid these medicines.

Prognosis

It is uncommon for people with ITP to present with severe bleeding (only 5% of affected people). However, within five years of diagnosis, 15% of affected individuals are hospitalized with bleeding complications.