Idiopathic thrombocytopenic purpura (ITP) is a disorder where the blood doesn’t clot normally, which can result in excessive bruising and bleeding. ITP, also called immune thrombocytopenic purpura, stems from unusually low levels of platelets, or “thrombocytes,” in the blood.
Platelets are produced in the bone marrow. They help stop bleeding by clumping together to form a clot that seals cuts or small tears in blood vessel walls. Without enough platelets, the blood is slow to clot. Internal bleeding or bleeding on or under the skin can result.
People with ITP often have many purple bruises, called purpura on the skin or mucous membranes inside the mouth. These bruises may also appear as pinpoint-sized red or purple dots on the skin and are called petechiae (pronounced “peh-TEE-kee-ay”). Petechiae may look like a rash.
According to the Mayo Clinic, ITP occurs in children and adults. In children, it is found in roughly equal numbers in boys and girls. In adults, ITP is most often seen after age 60 and is two to three times more common in women than in men (Mayo Clinic, 2010).
There are two types of ITP: acute (temporary or short-term) and chronic (long-lasting)
Acute ITP, the most common form of the disorder, usually lasts less than six months and mainly occurs in children.
Chronic ITP lasts six months or longer and is most commonly seen in adults, although teenagers and younger children can be affected.
The term “idiopathic” means “of unknown cause,” indicating that the exact cause of ITP has not been identified. However, it is generally believed that most cases of ITP are triggered by an autoimmune response that causes the immune system to view platelets as foreign bodies instead of the person’s own cells. In response, the immune system produces antibodies that mark platelets for destruction and removal by the spleen, which lowers the platelet count.
In children, ITP most commonly follows a virus, such as the flu, measles, or mumps. In adults, ITP can occasionally occur after a viral infection, but it is more commonly triggered by an immune disorder, pregnancy, or the use of certain drugs.
ITP is not contagious and cannot be passed from one person to another.
The most common symptoms are:
- easy bruising
- pinpoint-sized petechiae, often on the lower legs
- spontaneous nosebleeds or bleeding from the gums (for example, during dental work)
- blood in the urine or stool
- abnormally heavy menstruation
- prolonged bleeding from cuts
- profuse bleeding during surgery
Some people with ITP have no symptoms.
Your doctor will perform a complete physical exam. He or she will ask about any illnesses that may account for your symptoms and medications or other over-the-counter supplements you take that could lower your platelet count or otherwise cause you to bleed excessively.
Your doctor will also order a blood test that includes a complete blood count. The blood test may also include a test to determine if your blood contains platelet antibodies.
Your doctor may also perform a blood smear, in which some of your blood is placed on a glass slide and viewed under a microscope to verify the number of platelets seen in the complete blood count.
If your platelet count is low, your doctor may also order a bone marrow test. If you have ITP, your bone marrow will be normal. This is because your platelets are destroyed in the bloodstream and spleen after they leave the bone marrow. If your bone marrow is abnormal, your low platelet count will likely be caused by another disease process, not ITP.
Your doctor will tailor your treatment based on the total number of platelets and on how often and how much you bleed. In some cases, treatment may not be needed. For example, children usually get the acute form of ITP, which typically runs its course within six months.
Adults with less severe cases of ITP may also not require treatment. However, your doctor will still want to monitor your platelet count to make sure you don’t need treatment in the future.
If you or your child requires treatment, your doctor will likely prescribe medications as the first course of treatment. The most common medications used to treat ITP include:
- corticosteroids:Your doctor may prescribe prednisone, which can increase your platelet count by decreasing the activity of your immune system.
- intravenous immune globulin (IVIG): If your bleeding has reached a critical level or you are going to have surgery and need to quickly increase your platelet count, you may be given IVIG.
- thrombopoietin receptor agonists: these drugs, which include romiplostim and eltrombopag, help, prevent bruising and bleeding by causing your bone marrow to produce more platelets.
If these medications do not improve your symptoms, your doctor may choose to prescribe other drugs, including:
- immunosuppressants: These drugs, which include rituximab (Rituxan), cyclophosphamide (Cytoxan), and azathioprine (Imuran, Azasan), inhibit the activity of the immune system. However, they have significant side effects.
- experimental drugs: New medications that increase platelet production are being studied in clinical trials. Two of these, eltrombopag and AMG 531, appear to be well-tolerated, but studies are continuing to determine whether they are safe and effective.
- antibiotics: Some people with ITP are also infected with Helicobacter pylori, the same bacteria that cause most peptic ulcers. Antibiotic therapy to eliminate Helicobacter pylori has helped increase platelet counts in some people.
If you have severe ITP and medication doesn’t improve your symptoms or platelet count, your doctor may advise surgery to remove your spleen (splenectomy). The spleen is located in the upper left abdomen.
Splenectomy is not usually performed in children because of their high rate of spontaneous remission.
Severe or widespread ITP requires emergency treatment. This usually includes transfusions of concentrated platelets and intravenous administration of a corticosteroid such as methylprednisolone or intravenous immune globulin, or both.
Your doctor may also advise you to make some lifestyle changes, including:
- avoiding certain over-the-counter drugs that can affect platelet function, including aspirin, ibuprofen (Advil, Motrin, others) and the blood-thinning medication warfarin (Coumadin)
- limiting intake of alcohol as excessive alcohol consumption can adversely affect blood clotting
- choosing low-impact activities instead of competitive sports or other high-impact activities, to decrease your risk of injury and bleeding
ITP in Pregnancy
Treatment for pregnant women with ITP depends on the platelet count. If you have a mild case of ITP you will probably not need any treatment other than careful monitoring and regular blood tests.
If you have an extremely low platelet count or excessive bleeding, you are more likely to experience serious, heavy bleeding during and after delivery. In these cases, your doctor will work with you to determine a treatment plan that will help maintain a safe platelet count without adversely affecting the baby.
Although most babies born to mothers with ITP are not affected by the disorder, some are born with or develop a low platelet count soon after birth. In most cases, the platelet count will return to normal without any treatment. Treatment may be necessary in babies with very low platelet counts.
The most dangerous complication of ITP is bleeding, especially bleeding into the brain, which can be catastrophic or fatal. However, serious bleeding is rare. The treatments for ITP can have more complications than the disease itself.
Long-term use of corticosteroids can cause serious side effects, including:
- loss of muscle mass
- increased risk of infection
- high blood sugar or diabetes
Surgery to remove the spleen permanently increases the risk of infection as well as the risk of becoming ill if you get an infection. It is important to watch for any symptoms of infection and report them to your doctor promptly.
In the majority of cases, ITP isn’t serious or life threatening.
Acute ITP in children often runs its course and resolves within six months without treatment.
Chronic ITP can last for many years. People can live for many decades with the disease, even those with severe cases, and many are eventually able to safely discontinue treatment.